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Whitman ET, Ryan CP, Abraham WC, Addae A, Corcoran DL, Elliott ML, Hogan S, Ireland D, Keenan R, Knodt AR, Melzer TR, Poulton R, Ramrakha S, Sugden K, Williams BS, Zhou J, Hariri AR, Belsky DW, Moffitt TE, Caspi A. A blood biomarker of the pace of aging is associated with brain structure: replication across three cohorts. Neurobiol Aging 2024; 136:23-33. [PMID: 38301452 PMCID: PMC11017787 DOI: 10.1016/j.neurobiolaging.2024.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 01/16/2024] [Accepted: 01/19/2024] [Indexed: 02/03/2024]
Abstract
Biological aging is the correlated decline of multi-organ system integrity central to the etiology of many age-related diseases. A novel epigenetic measure of biological aging, DunedinPACE, is associated with cognitive dysfunction, incident dementia, and mortality. Here, we tested for associations between DunedinPACE and structural MRI phenotypes in three datasets spanning midlife to advanced age: the Dunedin Study (age=45 years), the Framingham Heart Study Offspring Cohort (mean age=63 years), and the Alzheimer's Disease Neuroimaging Initiative (mean age=75 years). We also tested four additional epigenetic measures of aging: the Horvath clock, the Hannum clock, PhenoAge, and GrimAge. Across all datasets (total N observations=3380; total N individuals=2322), faster DunedinPACE was associated with lower total brain volume, lower hippocampal volume, greater burden of white matter microlesions, and thinner cortex. Across all measures, DunedinPACE and GrimAge had the strongest and most consistent associations with brain phenotypes. Our findings suggest that single timepoint measures of multi-organ decline such as DunedinPACE could be useful for gauging nervous system health.
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Affiliation(s)
- Ethan T Whitman
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.
| | - Calen P Ryan
- Butler Columbia Aging Center, Columbia University Mailman School of Public Health, New York, USA
| | | | - Angela Addae
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - David L Corcoran
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Maxwell L Elliott
- Department of Psychology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Sean Hogan
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - David Ireland
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Ross Keenan
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand; Christchurch Radiology Group, Christchurch, New Zealand
| | - Annchen R Knodt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Tracy R Melzer
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand; Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Richie Poulton
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Sandhya Ramrakha
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Karen Sugden
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | | | - Jiayi Zhou
- Butler Columbia Aging Center, Columbia University Mailman School of Public Health, New York, USA
| | - Ahmad R Hariri
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Daniel W Belsky
- Butler Columbia Aging Center, Columbia University Mailman School of Public Health, New York, USA; Department of Epidemiology, Columbia University Mailman School of Public Health, New York, USA
| | - Terrie E Moffitt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA; Center for Genomic and Computational Biology, Duke University, Durham, NC, USA; King's College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London, UK; PROMENTA, Department of Psychology, University of Oslo, Norway; Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
| | - Avshalom Caspi
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA; Center for Genomic and Computational Biology, Duke University, Durham, NC, USA; King's College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London, UK; PROMENTA, Department of Psychology, University of Oslo, Norway; Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
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2
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Samavat M, Bartol TM, Bromer C, Hubbard DD, Hanka DC, Kuwajima M, Mendenhall JM, Parker PH, Bowden JB, Abraham WC, Sejnowski TJ, Harris KM. Long-Term Potentiation Produces a Sustained Expansion of Synaptic Information Storage Capacity in Adult Rat Hippocampus. bioRxiv 2024:2024.01.12.574766. [PMID: 38260636 PMCID: PMC10802612 DOI: 10.1101/2024.01.12.574766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Long-term potentiation (LTP) has become a standard model for investigating synaptic mechanisms of learning and memory. Increasingly, it is of interest to understand how LTP affects the synaptic information storage capacity of the targeted population of synapses. Here, structural synaptic plasticity during LTP was explored using three-dimensional reconstruction from serial section electron microscopy. Storage capacity was assessed by applying a new analytical approach, Shannon information theory, to delineate the number of functionally distinguishable synaptic strengths. LTP was induced by delta-burst stimulation of perforant pathway inputs to the middle molecular layer of hippocampal dentate granule cells in adult rats. Spine head volumes were measured as predictors of synaptic strength and compared between LTP and control hemispheres at 30 min and 2 hr after the induction of LTP. Synapses from the same axon onto the same dendrite were used to determine the precision of synaptic plasticity based on the similarity of their physical dimensions. Shannon entropy was measured by exploiting the frequency of spine heads in functionally distinguishable sizes to assess the degree to which LTP altered the number of bits of information storage. Outcomes from these analyses reveal that LTP expanded storage capacity; the distribution of spine head volumes was increased from 2 bits in controls to 3 bits at 30 min and 2.7 bits at 2 hr after the induction of LTP. Furthermore, the distribution of spine head volumes was more uniform across the increased number of functionally distinguishable sizes following LTP, thus achieving more efficient use of coding space across the population of synapses.
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Affiliation(s)
- Mohammad Samavat
- Department of Electrical and Computer Engineering, Jacobs School of Engineering, UC San Diego
- Computational Neurobiology Laboratory, The Salk Institute for Biological Sciences, La Jolla, CA 92037
| | - Thomas M Bartol
- Computational Neurobiology Laboratory, The Salk Institute for Biological Sciences, La Jolla, CA 92037
| | - Cailey Bromer
- Computational Neurobiology Laboratory, The Salk Institute for Biological Sciences, La Jolla, CA 92037
| | - Dusten D Hubbard
- Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712
| | - Dakota C Hanka
- Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712
| | - Masaaki Kuwajima
- Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712
| | - John M Mendenhall
- Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712
| | - Patrick H Parker
- Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712
| | - Jared B Bowden
- Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712
- Department of Neuroscience, The University of Texas at Austin, Austin, TX 78712
| | - Wickliffe C Abraham
- Department of Psychology and Brain Health Research Centre, University of Otago, Dunedin, 9016, New Zealand
| | - Terrence J Sejnowski
- Computational Neurobiology Laboratory, The Salk Institute for Biological Sciences, La Jolla, CA 92037
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Kristen M Harris
- Center for Learning and Memory, The University of Texas at Austin, Austin, TX 78712
- Department of Neuroscience, The University of Texas at Austin, Austin, TX 78712
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Jedlicka P, Tomko M, Robins A, Abraham WC. Contributions by metaplasticity to solving the Catastrophic Forgetting Problem: (Trends in Neurosciences, 45, 656-666, 2022). Trends Neurosci 2023; 46:893-894. [PMID: 37599184 DOI: 10.1016/j.tins.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
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Wright AL, Konen LM, Mockett BG, Morris GP, Singh A, Burbano LE, Milham L, Hoang M, Zinn R, Chesworth R, Tan RP, Royle GA, Clark I, Petrou S, Abraham WC, Vissel B. The Q/R editing site of AMPA receptor GluA2 subunit acts as an epigenetic switch regulating dendritic spines, neurodegeneration and cognitive deficits in Alzheimer's disease. Mol Neurodegener 2023; 18:65. [PMID: 37759260 PMCID: PMC10537207 DOI: 10.1186/s13024-023-00632-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 06/03/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND RNA editing at the Q/R site of GluA2 occurs with ~99% efficiency in the healthy brain, so that the majority of AMPARs contain GluA2(R) instead of the exonically encoded GluA2(Q). Reduced Q/R site editing infcreases AMPA receptor calcium permeability and leads to dendritic spine loss, neurodegeneration, seizures and learning impairments. Furthermore, GluA2 Q/R site editing is impaired in Alzheimer's disease (AD), raising the possibility that unedited GluA2(Q)-containing AMPARs contribute to synapse loss and neurodegeneration in AD. If true, then inhibiting expression of unedited GluA2(Q), while maintaining expression of GluA2(R), may be a novel strategy of preventing synapse loss and neurodegeneration in AD. METHODS We engineered mice with the 'edited' arginine codon (CGG) in place of the unedited glutamine codon (CAG) at position 607 of the Gria2 gene. We crossbred this line with the J20 mouse model of AD and conducted anatomical, electrophysiological and behavioural assays to determine the impact of eliminating unedited GluA2(Q) expression on AD-related phenotypes. RESULTS Eliminating unedited GluA2(Q) expression in AD mice prevented dendritic spine loss and hippocampal CA1 neurodegeneration as well as improved working and reference memory in the radial arm maze. These phenotypes were improved independently of Aβ pathology and ongoing seizure susceptibility. Surprisingly, our data also revealed increased spine density in non-AD mice with exonically encoded GluA2(R) as compared to their wild-type littermates, suggesting an unexpected and previously unknown role for unedited GluA2(Q) in regulating dendritic spines. CONCLUSION The Q/R editing site of the AMPA receptor subunit GluA2 may act as an epigenetic switch that regulates dendritic spines, neurodegeneration and memory deficits in AD.
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Affiliation(s)
- Amanda L Wright
- St Vincent's Clinical School, St Vincent's Hospital Sydney, Faculty of Medicine, University of New South Wales, Darlinghurst, NSW, 2010, Australia
- School of Rural Medicine, Charles Sturt University, Orange, NSW, 2800, Australia
| | - Lyndsey M Konen
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
| | - Bruce G Mockett
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Gary P Morris
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, TAS, 7005, Australia
| | - Anurag Singh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Lisseth Estefania Burbano
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Luke Milham
- St Vincent's Clinical School, St Vincent's Hospital Sydney, Faculty of Medicine, University of New South Wales, Darlinghurst, NSW, 2010, Australia
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, ON, N2G 1C5, Canada
| | - Raphael Zinn
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
| | - Rose Chesworth
- School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Richard P Tan
- Chronic Diseases, School of Medical Sciences, Faculty of Health and Medicine, University of Sydney, Sydney, NSW, 2050, Australia
- Charles Perkins Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Gordon A Royle
- Middlemore Hospital, Counties Manukau DHB, Otahuhu, Auckland, 1062, New Zealand
- Faculty of Medical and Health Sciences, University of Auckland, Grafton, Auckland, 1023, New Zealand
| | - Ian Clark
- Research School of Biology, Australian National University, Canberra, ACT, 0200, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Bryce Vissel
- St Vincent's Clinical School, St Vincent's Hospital Sydney, Faculty of Medicine, University of New South Wales, Darlinghurst, NSW, 2010, Australia.
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia.
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Whitman ET, Ryan CP, Abraham WC, Addae A, Corcoran DL, Elliott ML, Hogan S, Ireland D, Keenan R, Knodt AR, Melzer TR, Poulton R, Ramrakha S, Sugden K, Williams BS, Zhou J, Hariri AR, Belsky DW, Moffitt TE, Caspi A. A blood biomarker of accelerated aging in the body associates with worse structural integrity in the brain: replication across three cohorts. medRxiv 2023:2023.09.06.23295140. [PMID: 37732266 PMCID: PMC10508789 DOI: 10.1101/2023.09.06.23295140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Biological aging is the correlated decline of multi-organ system integrity central to the etiology of many age-related diseases. A novel epigenetic measure of biological aging, DunedinPACE, is associated with cognitive dysfunction, incident dementia, and mortality. Here, we tested for associations between DunedinPACE and structural MRI phenotypes in three datasets spanning midlife to advanced age: the Dunedin Study (age=45 years), the Framingham Heart Study Offspring Cohort (mean age=63 years), and the Alzheimer's Disease Neuroimaging Initiative (mean age=75 years). We also tested four additional epigenetic measures of aging: the Horvath clock, the Hannum clock, PhenoAge, and GrimAge. Across all datasets (total N observations=3,380; total N individuals=2,322), faster DunedinPACE was associated with lower total brain volume, lower hippocampal volume, and thinner cortex. In two datasets, faster DunedinPACE was associated with greater burden of white matter hyperintensities. Across all measures, DunedinPACE and GrimAge had the strongest and most consistent associations with brain phenotypes. Our findings suggest that single timepoint measures of multi-organ decline such as DunedinPACE could be useful for gauging nervous system health.
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Affiliation(s)
- Ethan T Whitman
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Calen P Ryan
- Butler Columbia Aging Center, Columbia University Mailman School of Public Health, New York, USA
| | | | - Angela Addae
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - David L Corcoran
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Maxwell L Elliott
- Department of Psychology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Sean Hogan
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - David Ireland
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Ross Keenan
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand
- Christchurch Radiology Group, Christchurch, New Zealand
| | - Annchen R Knodt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Tracy R Melzer
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Richie Poulton
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Sandhya Ramrakha
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Karen Sugden
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | | | - Jiayi Zhou
- Butler Columbia Aging Center, Columbia University Mailman School of Public Health, New York, USA
| | - Ahmad R Hariri
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Daniel W Belsky
- Butler Columbia Aging Center, Columbia University Mailman School of Public Health, New York, USA
- Department of Epidemiology, Columbia University Mailman School of Public Health, New York, USA
| | - Terrie E Moffitt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
- King's College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London, UK
- PROMENTA, Department of Psychology, University of Oslo, Norway
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
| | - Avshalom Caspi
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
- King's College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London, UK
- PROMENTA, Department of Psychology, University of Oslo, Norway
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
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6
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Whitman ET, Knodt AR, Elliott ML, Abraham WC, Cheyne K, Hogan S, Ireland D, Keenan R, Leung JH, Melzer TR, Poulton R, Purdy SC, Ramrakha S, Thorne PR, Caspi A, Moffitt TE, Hariri AR. Functional topography of the neocortex predicts covariation in complex cognitive and basic motor abilities. Cereb Cortex 2023; 33:8218-8231. [PMID: 37015900 PMCID: PMC10321095 DOI: 10.1093/cercor/bhad109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 04/06/2023] Open
Abstract
Although higher-order cognitive and lower-order sensorimotor abilities are generally regarded as distinct and studied separately, there is evidence that they not only covary but also that this covariation increases across the lifespan. This pattern has been leveraged in clinical settings where a simple assessment of sensory or motor ability (e.g. hearing, gait speed) can forecast age-related cognitive decline and risk for dementia. However, the brain mechanisms underlying cognitive, sensory, and motor covariation are largely unknown. Here, we examined whether such covariation in midlife reflects variability in common versus distinct neocortical networks using individualized maps of functional topography derived from BOLD fMRI data collected in 769 45-year-old members of a population-representative cohort. Analyses revealed that variability in basic motor but not hearing ability reflected individual differences in the functional topography of neocortical networks typically supporting cognitive ability. These patterns suggest that covariation in motor and cognitive abilities in midlife reflects convergence of function in higher-order neocortical networks and that gait speed may not be simply a measure of physical function but rather an integrative index of nervous system health.
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Affiliation(s)
- Ethan T Whitman
- Department of Psychology and Neuroscience, Duke University, Durham, NC 27710, USA
| | - Annchen R Knodt
- Department of Psychology and Neuroscience, Duke University, Durham, NC 27710, USA
| | - Maxwell L Elliott
- Department of Psychology, Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | | | - Kirsten Cheyne
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin 9016, New Zealand
| | - Sean Hogan
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin 9016, New Zealand
| | - David Ireland
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin 9016, New Zealand
| | - Ross Keenan
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, Auckland 1010, New Zealand
- Christchurch Radiology Group, Christchurch 8014, New Zealand
| | - Joan H Leung
- School of Psychology, University of Auckland, Auckland 1142, New Zealand
- Eisdell Moore Centre, University of Auckland, Auckland 1142, New Zealand
| | - Tracy R Melzer
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, Auckland 1010, New Zealand
- Department of Medicine, University of Otago, Christchurch 9016, New Zealand
| | - Richie Poulton
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin 9016, New Zealand
| | - Suzanne C Purdy
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, Auckland 1010, New Zealand
- School of Psychology, University of Auckland, Auckland 1142, New Zealand
- Eisdell Moore Centre, University of Auckland, Auckland 1142, New Zealand
| | - Sandhya Ramrakha
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin 9016, New Zealand
| | - Peter R Thorne
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, Auckland 1010, New Zealand
- Eisdell Moore Centre, University of Auckland, Auckland 1142, New Zealand
- School of Population Health, University of Auckland, Auckland 1142, New Zealand
| | - Avshalom Caspi
- Department of Psychology and Neuroscience, Duke University, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC 27710, USA
- King’s College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London SE5 8AF, UK
- PROMENTA, Department of Psychology, University of Oslo, NO-0316 Oslo, Norway
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA
| | - Terrie E Moffitt
- Department of Psychology and Neuroscience, Duke University, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC 27710, USA
- King’s College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London SE5 8AF, UK
- PROMENTA, Department of Psychology, University of Oslo, NO-0316 Oslo, Norway
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA
| | - Ahmad R Hariri
- Department of Psychology and Neuroscience, Duke University, Durham, NC 27710, USA
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Kleinjan MS, Buchta WC, Ogelman R, Hwang IW, Kuwajima M, Hubbard DD, Kareemo DJ, Prikhodko O, Olah SL, Gomez Wulschner LE, Abraham WC, Franco SJ, Harris KM, Oh WC, Kennedy MJ. Dually innervated dendritic spines develop in the absence of excitatory activity and resist plasticity through tonic inhibitory crosstalk. Neuron 2023; 111:1517. [PMID: 37141861 PMCID: PMC10234094 DOI: 10.1016/j.neuron.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
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8
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Barrett-Young A, Abraham WC, Cheung CY, Gale J, Hogan S, Ireland D, Keenan R, Knodt AR, Melzer TR, Moffitt TE, Ramrakha S, Tham YC, Wilson GA, Wong TY, Hariri AR, Poulton R. Associations Between Thinner Retinal Neuronal Layers and Suboptimal Brain Structural Integrity in a Middle-Aged Cohort. Eye Brain 2023; 15:25-35. [PMID: 36936476 PMCID: PMC10018220 DOI: 10.2147/eb.s402510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 02/28/2023] [Indexed: 03/12/2023] Open
Abstract
Purpose The retina has potential as a biomarker of brain health and Alzheimer's disease (AD) because it is the only part of the central nervous system which can be easily imaged and has advantages over brain imaging technologies. Few studies have compared retinal and brain measurements in a middle-aged sample. The objective of our study was to investigate whether retinal neuronal measurements were associated with structural brain measurements in a middle-aged population-based cohort. Participants and Methods Participants were members of the Dunedin Multidisciplinary Health and Development Study (n=1037; a longitudinal cohort followed from birth and at ages 3, 5, 7, 9, 11, 13, 15, 18, 21, 26, 32, 38, and most recently at age 45, when 94% of the living Study members participated). Retinal nerve fibre layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness were measured by optical coherence tomography (OCT). Brain age gap estimate (brainAGE), cortical surface area, cortical thickness, subcortical grey matter volumes, white matter hyperintensities, were measured by magnetic resonance imaging (MRI). Results Participants with both MRI and OCT data were included in the analysis (RNFL n=828, female n=413 [49.9%], male n=415 [50.1%]; GC-IPL n=825, female n=413 [50.1%], male n=412 [49.9%]). Thinner retinal neuronal layers were associated with older brain age, smaller cortical surface area, thinner average cortex, smaller subcortical grey matter volumes, and increased volume of white matter hyperintensities. Conclusion These findings provide evidence that the retinal neuronal layers reflect differences in midlife structural brain integrity consistent with increased risk for later AD, supporting the proposition that the retina may be an early biomarker of brain health.
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Affiliation(s)
| | | | - Carol Y Cheung
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong
| | - Jesse Gale
- Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand
| | - Sean Hogan
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - David Ireland
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Ross Keenan
- Department of Radiology, Christchurch Hospital, Christchurch, New Zealand
- Pacific Radiology Group, Christchurch, New Zealand
- New Zealand Brain Research Institute, Christchurch, New Zealand
| | - Annchen R Knodt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Tracy R Melzer
- New Zealand Brain Research Institute, Christchurch, New Zealand
- Department of Medicine, University of Otago, Christchurch, New Zealand
- School of Psychology, Speech and Hearing, University of Canterbury, Christchurch, New Zealand
| | - Terrie E Moffitt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Sandhya Ramrakha
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Yih Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Duke-NUS Medical School, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Graham A Wilson
- Department of Medicine, University of Otago, Dunedin, New Zealand
| | - Tien Yin Wong
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Tsinghua Medicine, Tsinghua University, Beijing, People’s Republic of China
| | - Ahmad R Hariri
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Richie Poulton
- Department of Psychology, University of Otago, Dunedin, New Zealand
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9
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Kleinjan MS, Buchta WC, Ogelman R, Hwang IW, Kuwajima M, Hubbard DD, Kareemo DJ, Prikhodko O, Olah SL, Gomez Wulschner LE, Abraham WC, Franco SJ, Harris KM, Oh WC, Kennedy MJ. Dually innervated dendritic spines develop in the absence of excitatory activity and resist plasticity through tonic inhibitory crosstalk. Neuron 2023; 111:362-371.e6. [PMID: 36395772 PMCID: PMC9899020 DOI: 10.1016/j.neuron.2022.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/13/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022]
Abstract
Dendritic spines can be directly connected to both inhibitory and excitatory presynaptic terminals, resulting in nanometer-scale proximity of opposing synaptic functions. While dually innervated spines (DiSs) are observed throughout the central nervous system, their developmental timeline and functional properties remain uncharacterized. Here we used a combination of serial section electron microscopy, live imaging, and local synapse activity manipulations to investigate DiS development and function in rodent hippocampus. Dual innervation occurred early in development, even on spines where the excitatory input was locally silenced. Synaptic NMDA receptor currents were selectively reduced at DiSs through tonic GABAB receptor signaling. Accordingly, spine enlargement normally associated with long-term potentiation on singly innervated spines (SiSs) was blocked at DiSs. Silencing somatostatin interneurons or pharmacologically blocking GABABRs restored NMDA receptor function and structural plasticity to levels comparable to neighboring SiSs. Thus, hippocampal DiSs are stable structures where function and plasticity are potently regulated by nanometer-scale GABAergic signaling.
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Affiliation(s)
- Mason S Kleinjan
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - William C Buchta
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Roberto Ogelman
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - In-Wook Hwang
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Masaaki Kuwajima
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Dusten D Hubbard
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Dean J Kareemo
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Olga Prikhodko
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Samantha L Olah
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Luis E Gomez Wulschner
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Santos J Franco
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kristen M Harris
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Won Chan Oh
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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10
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Gibbons TD, Cotter JD, Ainslie PN, Abraham WC, Mockett BG, Campbell HA, Jones EMW, Jenkins EJ, Thomas KN. Fasting for 20 h does not affect exercise-induced increases in circulating BDNF in humans. J Physiol 2023. [PMID: 36631068 DOI: 10.1113/jp283582] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 11/18/2022] [Indexed: 01/13/2023] Open
Abstract
Intermittent fasting and exercise provide neuroprotection from age-related cognitive decline. A link between these two seemingly distinct stressors is their capability to steer the brain away from exclusively glucose metabolism. This cerebral substrate switch has been implicated in upregulating brain-derived neurotrophic factor (BDNF), a protein involved in neuroplasticity, learning and memory, and may underlie some of these neuroprotective effects. We examined the isolated and interactive effects of (1) 20-h fasting, (2) 90-min light exercise, and (3) high-intensity exercise on peripheral venous BDNF in 12 human volunteers. A follow-up study isolated the influence of cerebrovascular shear stress on circulating BDNF. Fasting for 20 h decreased glucose and increased ketones (P ≤ 0.0157) but had no effect on BDNF (P ≥ 0.4637). Light cycling at 25% of peak oxygen uptake ( V ̇ O 2 peak ${\dot V_{{{\rm{O}}_{\rm{2}}}{\rm{peak}}}}$ ) increased serum BDNF by 6 ± 8% (independent of being fed or fasted) and was mediated by a 7 ± 6% increase in platelets (P < 0.0001). Plasma BDNF was increased from 336 pg l-1 [46,626] to 390 pg l-1 [127,653] by 90-min of light cycling (P = 0.0128). Six 40-s intervals at 100% of V ̇ O 2 peak ${\dot V_{{{\rm{O}}_{\rm{2}}}{\rm{peak}}}}$ increased plasma and serum BDNF, as well as the BDNF-per-platelet ratio 4- to 5-fold more than light exercise did (P ≤ 0.0044). Plasma BDNF was correlated with circulating lactate during the high-intensity intervals (r = 0.47, P = 0.0057), but not during light exercise (P = 0.7407). Changes in cerebral shear stress - whether occurring naturally during exercise or induced experimentally with inspired CO2 - did not correspond with changes in BDNF (P ≥ 0.2730). BDNF responses to low-intensity exercise are mediated by increased circulating platelets, and increasing either exercise duration or particularly intensity is required to liberate free BDNF. KEY POINTS: Intermittent fasting and exercise both have potent neuroprotective effects and an acute upregulation of brain-derived neurotrophic factor (BDNF) appears to be a common mechanistic link. Switching the brain's fuel source from glucose to either ketone bodies or lactate, i.e. a cerebral substrate switch, has been shown to promote BDNF production in the rodent brain. Fasting for 20 h caused a 9-fold increase in ketone body delivery to the brain but had no effect on any metric of BDNF in peripheral circulation at rest. Prolonged (90 min) light cycling exercise increased plasma- and serum-derived BDNF irrespective of being fed or fasted and seemed to be independent of changes in cerebral shear stress. Six minutes of high-intensity cycling intervals increased every metric of circulating BDNF by 4 to 5 times more than prolonged low-intensity cycling; the increase in plasma-derived BDNF was correlated with a 6-fold increase in circulating lactate irrespective of feeding or fasting. Compared to 1 day of fasting with or without prolonged light exercise, high-intensity exercise is a much more efficient means to increase BDNF in circulation.
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Affiliation(s)
- Travis D Gibbons
- School of Physical Education, Sport & Exercise Sciences, University of Otago, Dunedin, New Zealand.,Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan, School of Health and Exercise Science, Kelowna, British Columbia, Canada
| | - James D Cotter
- School of Physical Education, Sport & Exercise Sciences, University of Otago, Dunedin, New Zealand
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan, School of Health and Exercise Science, Kelowna, British Columbia, Canada
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Bruce G Mockett
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Holly A Campbell
- Department of Surgical Sciences, University of Otago, Dunedin, New Zealand
| | - Emma M W Jones
- School of Physical Education, Sport & Exercise Sciences, University of Otago, Dunedin, New Zealand.,Department of Surgical Sciences, University of Otago, Dunedin, New Zealand
| | - Elliott J Jenkins
- School of Physical Education, Sport & Exercise Sciences, University of Otago, Dunedin, New Zealand.,Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Kate N Thomas
- Department of Surgical Sciences, University of Otago, Dunedin, New Zealand
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11
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Whitman ET, Knodt AR, Elliott ML, Abraham WC, Cheyne K, Hogan S, Ireland D, Keenan R, Lueng JH, Melzer TR, Poulton R, Purdy SC, Ramrakha S, Thorne PR, Caspi A, Moffitt TE, Hariri AR. Functional Topography of the Neocortex Predicts Covariation in Complex Cognitive and Basic Motor Abilities. bioRxiv 2023:2023.01.09.523297. [PMID: 36711683 PMCID: PMC9881949 DOI: 10.1101/2023.01.09.523297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Although higher-order cognitive and lower-order sensorimotor abilities are generally regarded as distinct and studied separately, there is evidence that they not only covary but also that this covariation increases across the lifespan. This pattern has been leveraged in clinical settings where a simple assessment of sensory or motor ability (e.g., hearing, gait speed) can forecast age-related cognitive decline and risk for dementia. However, the brain mechanisms underlying cognitive, sensory, and motor covariation are largely unknown. Here, we examined whether such covariation in midlife reflects variability in common versus distinct neocortical networks using individualized maps of functional topography derived from BOLD fMRI data collected in 769 45-year old members of a population-representative cohort. Analyses revealed that variability in basic motor but not hearing ability reflected individual differences in the functional topography of neocortical networks typically supporting cognitive ability. These patterns suggest that covariation in motor and cognitive abilities in midlife reflects convergence of function in higher-order neocortical networks and that gait speed may not be simply a measure of physical function but rather an integrative index of nervous system health.
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Affiliation(s)
- Ethan T. Whitman
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Annchen R. Knodt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Maxwell L. Elliott
- Department of Psychology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | | | - Kirsten Cheyne
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Sean Hogan
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - David Ireland
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Ross Keenan
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand
- Christchurch Radiology Group, Christchurch, New Zealand
| | - Joan H. Lueng
- School of Psychology, University of Auckland, New Zealand
- Eisdell Moore Centre, University of Auckland, New Zealand
| | - Tracy R. Melzer
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Richie Poulton
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Suzanne C. Purdy
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand
- School of Psychology, University of Auckland, New Zealand
- Eisdell Moore Centre, University of Auckland, New Zealand
| | - Sandhya Ramrakha
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Peter R. Thorne
- Brain Research New Zealand-Rangahau Roro Aotearoa, Centre of Research Excellence, Universities of Auckland and Otago, New Zealand
- Eisdell Moore Centre, University of Auckland, New Zealand
- School of Population Health, University of Auckland, New Zealand
| | - Avshalom Caspi
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
- King’s College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London, UK
- PROMENTA, Department of Psychology, University of Oslo, Norway
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
| | - Terrie E. Moffitt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
- King’s College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, & Neuroscience, London, UK
- PROMENTA, Department of Psychology, University of Oslo, Norway
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
| | - Ahmad R. Hariri
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
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12
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Reuben A, Moffitt TE, Abraham WC, Ambler A, Elliott ML, Hariri AR, Harrington H, Hogan S, Houts RM, Ireland D, Knodt AR, Leung J, Pearson A, Poulton R, Purdy SC, Ramrakha S, Rasmussen LJH, Sugden K, Thorne PR, Williams B, Wilson G, Caspi A. Improving risk indexes for Alzheimer's disease and related dementias for use in midlife. Brain Commun 2022; 4:fcac223. [PMID: 36213312 PMCID: PMC9535507 DOI: 10.1093/braincomms/fcac223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/01/2022] [Accepted: 09/01/2022] [Indexed: 11/07/2022] Open
Abstract
Knowledge of a person’s risk for Alzheimer’s disease and related dementias (ADRDs) is required to triage candidates for preventive interventions, surveillance, and treatment trials. ADRD risk indexes exist for this purpose, but each includes only a subset of known risk factors. Information missing from published indexes could improve risk prediction. In the Dunedin Study of a population-representative New Zealand-based birth cohort followed to midlife (N = 938, 49.5% female), we compared associations of four leading risk indexes with midlife antecedents of ADRD against a novel benchmark index comprised of nearly all known ADRD risk factors, the Dunedin ADRD Risk Benchmark (DunedinARB). Existing indexes included the Cardiovascular Risk Factors, Aging, and Dementia index (CAIDE), LIfestyle for BRAin health index (LIBRA), Australian National University Alzheimer’s Disease Risk Index (ANU-ADRI), and risks selected by the Lancet Commission on Dementia. The Dunedin benchmark was comprised of 48 separate indicators of risk organized into 10 conceptually distinct risk domains. Midlife antecedents of ADRD treated as outcome measures included age-45 measures of brain structural integrity [magnetic resonance imaging-assessed: (i) machine-learning-algorithm-estimated brain age, (ii) log-transformed volume of white matter hyperintensities, and (iii) mean grey matter volume of the hippocampus] and measures of brain functional integrity [(i) objective cognitive function assessed via the Wechsler Adult Intelligence Scale-IV, (ii) subjective problems in everyday cognitive function, and (iii) objective cognitive decline measured as residualized change in cognitive scores from childhood to midlife on matched Weschler Intelligence scales]. All indexes were quantitatively distributed and proved informative about midlife antecedents of ADRD, including algorithm-estimated brain age (β's from 0.16 to 0.22), white matter hyperintensities volume (β's from 0.16 to 0.19), hippocampal volume (β's from −0.08 to −0.11), tested cognitive deficits (β's from −0.36 to −0.49), everyday cognitive problems (β's from 0.14 to 0.38), and longitudinal cognitive decline (β's from −0.18 to −0.26). Existing indexes compared favourably to the comprehensive benchmark in their association with the brain structural integrity measures but were outperformed in their association with the functional integrity measures, particularly subjective cognitive problems and tested cognitive decline. Results indicated that existing indexes could be improved with targeted additions, particularly of measures assessing socioeconomic status, physical and sensory function, epigenetic aging, and subjective overall health. Existing premorbid ADRD risk indexes perform well in identifying linear gradients of risk among members of the general population at midlife, even when they include only a small subset of potential risk factors. They could be improved, however, with targeted additions to more holistically capture the different facets of risk for this multiply determined, age-related disease.
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Affiliation(s)
- Aaron Reuben
- Correspondence to: Aaron Reuben Department of Psychology and Neuroscience Duke University, Durham, NC 27708, USA E-mail:
| | - Terrie E Moffitt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA,Center for Genomic and Computational Biology, Duke University, Durham, NC, USA,Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA,King’s College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, and Neuroscience, London, UK,PROMENTA, Department of Psychology, University of Oslo, Oslo, Norway
| | - Wickliffe C Abraham
- Brain Health Research Centre, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Antony Ambler
- King’s College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, and Neuroscience, London, UK
| | - Maxwell L Elliott
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Ahmad R Hariri
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Honalee Harrington
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Sean Hogan
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Renate M Houts
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - David Ireland
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Annchen R Knodt
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Joan Leung
- School of Psychology, The University of Auckland, Auckland, New Zealand
| | - Amber Pearson
- Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, MI, USA,Department of Public Health, University of Otago, Wellington, New Zealand
| | - Richie Poulton
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Suzanne C Purdy
- Center for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Sandhya Ramrakha
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Line J H Rasmussen
- Department of Clinical Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
| | - Karen Sugden
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Peter R Thorne
- Center for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand,Faculty of Medical and Health Sciences, Department of Physiology, The University of Auckland, Auckland, New Zealand,Section of Audiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Benjamin Williams
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Graham Wilson
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand,Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Avshalom Caspi
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA,Center for Genomic and Computational Biology, Duke University, Durham, NC, USA,Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA,King’s College London, Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, and Neuroscience, London, UK,PROMENTA, Department of Psychology, University of Oslo, Oslo, Norway
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13
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Abraham WC, Geffen LB, McLachlan EM, Richards LJ, Rostas JAP. A brief history of the Australasian Neuroscience Society. J Hist Neurosci 2022; 31:395-408. [PMID: 34499016 DOI: 10.1080/0964704x.2021.1970481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The collective efforts of Australasian neuroscientists over the past 50 years to forge a binational presence are reviewed in this article. The events in the 1970s leading to the formation of an informal Australian Neurosciences Society are discussed in the context of the international emergence of neuroscience as an interdisciplinary science. Thereafter, the establishment in 1980 of the Australian Neuroscience Society, subsequently renamed as the Australasian Neuroscience Society (ANS), is described. The achievements of ANS-including its active role in developing national, regional, and global cooperation to promote neuroscience-are chronicled over successive decades, followed by a discussion of the future challenges facing the society and its associated neuroscience institutions.
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Affiliation(s)
- Wickliffe C Abraham
- Department of Psychology and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | | | - Elspeth M McLachlan
- Neuroscience Research Australia and University of New South Wales, Sydney, Australia
| | - Linda J Richards
- Queensland Brain Institute and School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - John A P Rostas
- Hunter Medical Research Institute and School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
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14
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Jedlicka P, Tomko M, Robins A, Abraham WC. Contributions by metaplasticity to solving the Catastrophic Forgetting Problem. Trends Neurosci 2022; 45:656-666. [PMID: 35798611 DOI: 10.1016/j.tins.2022.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/06/2022] [Accepted: 06/09/2022] [Indexed: 10/17/2022]
Abstract
Catastrophic forgetting (CF) refers to the sudden and severe loss of prior information in learning systems when acquiring new information. CF has been an Achilles heel of standard artificial neural networks (ANNs) when learning multiple tasks sequentially. The brain, by contrast, has solved this problem during evolution. Modellers now use a variety of strategies to overcome CF, many of which have parallels to cellular and circuit functions in the brain. One common strategy, based on metaplasticity phenomena, controls the future rate of change at key connections to help retain previously learned information. However, the metaplasticity properties so far used are only a subset of those existing in neurobiology. We propose that as models become more sophisticated, there could be value in drawing on a richer set of metaplasticity rules, especially when promoting continual learning in agents moving about the environment.
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Affiliation(s)
- Peter Jedlicka
- ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, Giessen, Germany; Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt/Main, Germany; Frankfurt Institute for Advanced Studies, Frankfurt 60438, Germany.
| | - Matus Tomko
- ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, Giessen, Germany; Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Anthony Robins
- Department of Computer Science, University of Otago, Dunedin 9016, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand.
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15
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Ohline SM, Liu X, Ibrahim MF, Mockett BM, Empson RM, Abraham WC, Iremonger KJ, Jones PP. Altered membrane properties but unchanged intrinsic excitability and spontaneous postsynaptic currents in an aged APPswe/PS1dE9 model of Alzheimer’s disease. Front Cell Neurosci 2022; 16:958876. [PMID: 36090787 PMCID: PMC9459330 DOI: 10.3389/fncel.2022.958876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
Neuronal hyperexcitability in Alzheimer’s disease (AD) models is thought to either contribute to the formation of amyloid beta plaques or result from their formation. Neuronal hyperexcitability has been shown in the cerebral cortex of the widely used young APPswe/PS1dE9 mice, which have accelerated plaque formation. However, it is currently unclear if hyperexcitability also occurs in CA1 hippocampal neurons of aged animals in this model. In the present work, we have compared intrinsic excitability and spontaneous synaptic inputs from CA1 pyramidal cells of 8-month-old APPswe/PS1dE9 and wildtype control mice. We find no change in intrinsic excitability or spontaneous postsynaptic currents (PSCs) between groups. We did, however, find a reduced input resistance and an increase in hyperpolarization-activated sag current. These results are consistent with findings from other aged AD model mice, including the widely used 5xFAD and 3xTg. Together these results suggest that neuronal hyperexcitability is not a consistent feature of all AD mouse models, particularly at advanced ages.
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Affiliation(s)
- Shane M. Ohline
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- HeartOtago, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- *Correspondence: Shane M. Ohline,
| | - Xinhuai Liu
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Mohamed F. Ibrahim
- Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, United Kingdom
| | - Bruce M. Mockett
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Ruth M. Empson
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Wickliffe C. Abraham
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Karl J. Iremonger
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Peter P. Jones
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- HeartOtago, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Peter P. Jones,
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16
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Ahmed S, Jing Y, Mockett BG, Zhang H, Abraham WC, Liu P. Partial Endothelial Nitric Oxide Synthase Deficiency Exacerbates Cognitive Deficit and Amyloid Pathology in the APPswe/PS1ΔE9 Mouse Model of Alzheimer’s Disease. Int J Mol Sci 2022; 23:ijms23137316. [PMID: 35806318 PMCID: PMC9266765 DOI: 10.3390/ijms23137316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 01/25/2023] Open
Abstract
Increasing evidence implicates endothelial dysfunction in the pathogenesis of Alzheimer’s disease (AD). Nitric oxide (NO) derived from endothelial NO synthase (eNOS) is essential in maintaining cerebrovascular function and can modulate the production and clearance of amyloid beta (Aβ). APPswe/PSdE1 (APP/PS1) mice display age-related Aβ accumulation and memory deficits. In order to make the model more clinically relevant with an element of endothelial dysfunction, we generated APP/PS1/eNOS+/− mice by crossing complete eNOS deficient (eNOS−/−) mice and APP/PS1 mice. APP/PS1/eNOS+/− mice at 8 months of age displayed a more severe spatial working memory deficit relative to age-matched APP/PS1 mice. Moreover, immunohistochemistry and immunoblotting revealed significantly increased Aβ plaque load in the brains of APP/PS1/eNOS+/− mice, concomitant with upregulated BACE-1 (hence increased Aβ production), downregulated insulin-degrading enzyme (hence reduced Aβ clearance) and increased immunoreactivity and expression of microglia. The present study, for the first time, demonstrated that partial eNOS deficiency exacerbated behavioral dysfunction, Aβ brain deposition, and microglial pathology in APP/PS1 mice, further implicating endothelial dysfunction in the pathogenesis of AD. The present findings also provide the scientific basis for developing preventive and/or therapeutic strategies by targeting endothelial dysfunction.
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Affiliation(s)
- Sara Ahmed
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand; (S.A.); (Y.J.)
| | - Yu Jing
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand; (S.A.); (Y.J.)
| | - Bruce G. Mockett
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand; (B.G.M.); (W.C.A.)
| | - Hu Zhang
- School of Pharmacy, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand;
| | - Wickliffe C. Abraham
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand; (B.G.M.); (W.C.A.)
| | - Ping Liu
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand; (S.A.); (Y.J.)
- Correspondence:
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17
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Harris KM, Hubbard DD, Kuwajima M, Abraham WC, Bourne JN, Bowden JB, Haessly A, Mendenhall JM, Parker PH, Shi B, Spacek J. Dendritic Spine Density Scales with Microtubule Number in Rat Hippocampal Dendrites. Neuroscience 2022; 489:84-97. [PMID: 35218884 PMCID: PMC9038701 DOI: 10.1016/j.neuroscience.2022.02.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 12/14/2022]
Abstract
Microtubules deliver essential resources to and from synapses. Three-dimensional reconstructions in rat hippocampus reveal a sampling bias regarding spine density that needs to be controlled for dendrite caliber and resource delivery based on microtubule number. The strength of this relationship varies across dendritic arbors, as illustrated for area CA1 and dentate gyrus. In both regions, proximal dendrites had more microtubules than distal dendrites. For CA1 pyramidal cells, spine density was greater on thicker than thinner dendrites in stratum radiatum, or on the more uniformly thin terminal dendrites in stratum lacunosum moleculare. In contrast, spine density was constant across the cone shaped arbor of tapering dendrites from dentate granule cells. These differences suggest that thicker dendrites supply microtubules to subsequent dendritic branches and local dendritic spines, whereas microtubules in thinner dendrites need only provide resources to local spines. Most microtubules ran parallel to dendrite length and associated with long, presumably stable mitochondria, which occasionally branched into lateral dendritic branches. Short, presumably mobile, mitochondria were tethered to microtubules that bent and appeared to direct them into a thin lateral branch. Prior work showed that dendritic segments with the same number of microtubules had elevated resources in subregions of their dendritic shafts where spine synapses had enlarged, and spine clusters had formed. Thus, additional microtubules were not required for redistribution of resources locally to growing spines or synapses. These results provide new understanding about the potential for microtubules to regulate resource delivery to and from dendritic branches and locally among dendritic spines.
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Affiliation(s)
- Kristen M Harris
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States.
| | - Dusten D Hubbard
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Masaaki Kuwajima
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Wickliffe C Abraham
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Jennifer N Bourne
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Jared B Bowden
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Andrea Haessly
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - John M Mendenhall
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Patrick H Parker
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Bitao Shi
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
| | - Josef Spacek
- Department of Neuroscience, Center for Learning and Memory, University of Texas at Austin, Austin, TX, United States
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18
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Smyth LCD, Murray HC, Hill M, van Leeuwen E, Highet B, Magon NJ, Osanlouy M, Mathiesen SN, Mockett B, Singh-Bains MK, Morris VK, Clarkson AN, Curtis MA, Abraham WC, Hughes SM, Faull RLM, Kettle AJ, Dragunow M, Hampton MB. Neutrophil-vascular interactions drive myeloperoxidase accumulation in the brain in Alzheimer's disease. Acta Neuropathol Commun 2022; 10:38. [PMID: 35331340 PMCID: PMC8944147 DOI: 10.1186/s40478-022-01347-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/11/2022] [Indexed: 01/13/2023] Open
Abstract
INTRODUCTION Neutrophil accumulation is a well-established feature of Alzheimer's disease (AD) and has been linked to cognitive impairment by modulating disease-relevant neuroinflammatory and vascular pathways. Neutrophils express high levels of the oxidant-generating enzyme myeloperoxidase (MPO), however there has been controversy regarding the cellular source and localisation of MPO in the AD brain. MATERIALS AND METHODS We used immunostaining and immunoassays to quantify the accumulation of neutrophils in human AD tissue microarrays and in the brains of APP/PS1 mice. We also used multiplexed immunolabelling to define the presence of NETs in AD. RESULTS There was an increase in neutrophils in AD brains as well as in the murine APP/PS1 model of AD. Indeed, MPO expression was almost exclusively confined to S100A8-positive neutrophils in both human AD and murine APP/PS1 brains. The vascular localisation of neutrophils in both human AD and mouse models of AD was striking and driven by enhanced neutrophil adhesion to small vessels. We also observed rare infiltrating neutrophils and deposits of MPO around plaques. Citrullinated histone H3, a marker of neutrophil extracellular traps (NETs), was also detected in human AD cases at these sites, indicating the presence of extracellular MPO in the vasculature. Finally, there was a reduction in the endothelial glycocalyx in AD that may be responsible for non-productive neutrophil adhesion to the vasculature. CONCLUSION Our report indicates that vascular changes may drive neutrophil adhesion and NETosis, and that neutrophil-derived MPO may lead to vascular oxidative stress and be a relevant therapeutic target in AD.
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Affiliation(s)
- Leon C. D. Smyth
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
- Department of Pathology and Immunology, Center for Brain Immunology and Glia, Washington University in St. Louis, Campus, Box 8118, St. Louis, MO USA
| | - Helen C. Murray
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Madison Hill
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Eve van Leeuwen
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Blake Highet
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Nicholas J. Magon
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Mahyar Osanlouy
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Sophie N. Mathiesen
- Department of Psychology, University of Otago, Dunedin, New Zealand
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Bruce Mockett
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Malvindar K. Singh-Bains
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Vanessa K. Morris
- School of Biological Science, University of Canterbury, Canterbury, New Zealand
| | | | - Maurice A. Curtis
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | | | | | - Richard L. M. Faull
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Anatomy With Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Anthony J. Kettle
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
| | - Mike Dragunow
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Mark B. Hampton
- Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, PO Box 4345, Christchurch, 8140 New Zealand
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19
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Lee K, Jung Y, Vyas Y, Skelton I, Abraham WC, Hsueh YP, Montgomery JM. Dietary zinc supplementation rescues fear-based learning and synaptic function in the Tbr1 +/- mouse model of autism spectrum disorders. Mol Autism 2022; 13:13. [PMID: 35303947 PMCID: PMC8932001 DOI: 10.1186/s13229-022-00494-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/07/2022] [Indexed: 12/02/2022] Open
Abstract
Background Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by a dyad of behavioural symptoms—social and communication deficits and repetitive behaviours. Multiple aetiological genetic and environmental factors have been identified as causing or increasing the likelihood of ASD, including serum zinc deficiency. Our previous studies revealed that dietary zinc supplementation can normalise impaired social behaviours, excessive grooming, and heightened anxiety in a Shank3 mouse model of ASD, as well as the amelioration of synapse dysfunction. Here, we have examined the efficacy and breadth of dietary zinc supplementation as an effective therapeutic strategy utilising a non-Shank-related mouse model of ASD—mice with Tbr1 haploinsufficiency. Methods We performed behavioural assays, amygdalar slice whole-cell patch-clamp electrophysiology, and immunohistochemistry to characterise the synaptic mechanisms underlying the ASD-associated behavioural deficits observed in Tbr1+/− mice and the therapeutic potential of dietary zinc supplementation. Two-way analysis of variance (ANOVA) with Šídák's post hoc test and one-way ANOVA with Tukey’s post hoc multiple comparisons were performed for statistical analysis. Results Our data show that dietary zinc supplementation prevents impairments in auditory fear memory and social interaction, but not social novelty, in the Tbr1+/− mice. Tbr1 haploinsufficiency did not induce excessive grooming nor elevate anxiety in mice. At the synaptic level, dietary zinc supplementation reversed α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and N-methyl-d-aspartate receptor (NMDAR) hypofunction and normalised presynaptic function at thalamic-lateral amygdala (LA) synapses that are crucial for auditory fear memory. In addition, the zinc supplemented diet significantly restored the synaptic puncta density of the GluN1 subunit essential for functional NMDARs as well as SHANK3 expression in both the basal and lateral amygdala (BLA) of Tbr1+/− mice. Limitations The therapeutic effect of dietary zinc supplementation observed in rodent models may not reproduce the same effects in human patients. The effect of dietary zinc supplementation on synaptic function in other brain structures affected by Tbr1 haploinsufficiency including olfactory bulb and anterior commissure will also need to be examined. Conclusions Our data further the understanding of the molecular mechanisms underlying the effect of dietary zinc supplementation and verify the efficacy and breadth of its application as a potential treatment strategy for ASD.
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Affiliation(s)
- Kevin Lee
- Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Yewon Jung
- Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Yukti Vyas
- Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.,INSERM, Neurocentre Magendie, U1215, Bordeaux, France
| | - Imogen Skelton
- Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, 128, Section 2, Academia Rd., Taipei, 11529, Taiwan
| | - Johanna M Montgomery
- Department of Physiology and Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.
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20
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Guévremont D, Tsui H, Knight R, Fowler CJ, Masters CL, Martins RN, Abraham WC, Tate WP, Cutfield NJ, Williams JM. Plasma microRNA vary in association with the progression of Alzheimer's disease. Alzheimers Dement (Amst) 2022; 14:e12251. [PMID: 35141392 PMCID: PMC8817674 DOI: 10.1002/dad2.12251] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 08/09/2021] [Indexed: 12/11/2022]
Abstract
Introduction Early intervention in Alzheimer's disease (AD) requires the development of an easily administered test that is able to identify those at risk. Focusing on microRNA robustly detected in plasma and standardizing the analysis strategy, we sought to identify disease‐stage specific biomarkers. Methods Using TaqMan microfluidics arrays and a statistical consensus approach, we assessed plasma levels of 185 neurodegeneration‐related microRNA, in cohorts of cognitively normal amyloid β‐positive (CN‐Aβ+), mild cognitive impairment (MCI), and Alzheimer's disease (AD) participants, relative to their respective controls. Results Distinct disease stage microRNA biomarkers were identified, shown to predict membership of the groups (area under the curve [AUC] >0.8) and were altered dynamically with AD progression in a longitudinal study. Bioinformatics demonstrated that these microRNA target known AD‐related pathways, such as the Phosphoinositide 3‐kinase (PI3K‐Akt) signalling pathway. Furthermore, a significant correlation was found between miR‐27a‐3p, miR‐27b‐3p, and miR‐324‐5p and amyloid beta load. Discussion Our results show that microRNA signatures alter throughout the progression of AD, reflect the underlying disease pathology, and may prove to be useful diagnostic markers.
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Affiliation(s)
- Diane Guévremont
- Department of Anatomy University of Otago Dunedin New Zealand.,Brain Health Research Centre University of Otago Dunedin New Zealand.,Brain Research New Zealand, Rangahau Roro Aotearoa University of Otago Dunedin New Zealand
| | - Helen Tsui
- Brain Health Research Centre University of Otago Dunedin New Zealand.,Brain Research New Zealand, Rangahau Roro Aotearoa University of Otago Dunedin New Zealand.,Department of Psychology University of Otago Dunedin New Zealand
| | - Robert Knight
- Brain Health Research Centre University of Otago Dunedin New Zealand.,Brain Research New Zealand, Rangahau Roro Aotearoa University of Otago Dunedin New Zealand.,Department of Psychology University of Otago Dunedin New Zealand
| | - Chris J Fowler
- The Florey Institute, The University of Melbourne, Parkville, Victoria, Australia. MD The Florey Institute The University of Melbourne Parkville Victoria Australia.,Australian Imaging Biomarkers and Lifestyle (AIBL) Research Group Australia
| | - Colin L Masters
- The Florey Institute, The University of Melbourne, Parkville, Victoria, Australia. MD The Florey Institute The University of Melbourne Parkville Victoria Australia.,Australian Imaging Biomarkers and Lifestyle (AIBL) Research Group Australia
| | - Ralph N Martins
- Australian Imaging Biomarkers and Lifestyle (AIBL) Research Group Australia.,Department of Biomedical Sciences Macquarie University New South Wales Australia
| | - Wickliffe C Abraham
- Brain Health Research Centre University of Otago Dunedin New Zealand.,Brain Research New Zealand, Rangahau Roro Aotearoa University of Otago Dunedin New Zealand.,Department of Psychology University of Otago Dunedin New Zealand
| | - Warren P Tate
- Brain Health Research Centre University of Otago Dunedin New Zealand.,Brain Research New Zealand, Rangahau Roro Aotearoa University of Otago Dunedin New Zealand.,Department of Biochemistry University of Otago Dunedin New Zealand
| | - Nicholas J Cutfield
- Brain Health Research Centre University of Otago Dunedin New Zealand.,Brain Research New Zealand, Rangahau Roro Aotearoa University of Otago Dunedin New Zealand.,Department of Medicine University of Otago Dunedin New Zealand
| | - Joanna M Williams
- Department of Anatomy University of Otago Dunedin New Zealand.,Brain Health Research Centre University of Otago Dunedin New Zealand.,Brain Research New Zealand, Rangahau Roro Aotearoa University of Otago Dunedin New Zealand
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21
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Ohline SM, Chan C, Schoderboeck L, Wicky HE, Tate WP, Hughes SM, Abraham WC. Effect of soluble amyloid precursor protein-alpha on adult hippocampal neurogenesis in a mouse model of Alzheimer's disease. Mol Brain 2022; 15:5. [PMID: 34980189 PMCID: PMC8721980 DOI: 10.1186/s13041-021-00889-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/19/2021] [Indexed: 01/08/2023] Open
Abstract
Soluble amyloid precursor protein-alpha (sAPPα) is a regulator of neuronal and memory mechanisms, while also having neurogenic and neuroprotective effects in the brain. As adult hippocampal neurogenesis is impaired in Alzheimer’s disease, we tested the hypothesis that sAPPα delivery would rescue adult hippocampal neurogenesis in an APP/PS1 mouse model of Alzheimer’s disease. An adeno-associated virus-9 (AAV9) encoding murine sAPPα was injected into the hippocampus of 8-month-old wild-type and APP/PS1 mice, and later two different thymidine analogues (XdU) were systemically injected to label adult-born cells at different time points after viral transduction. The proliferation of adult-born cells, cell survival after eight weeks, and cell differentiation into either neurons or astrocytes was studied. Proliferation was impaired in APP/PS1 mice but was restored to wild-type levels by viral expression of sAPPα. In contrast, sAPPα overexpression failed to rescue the survival of XdU+-labelled cells that was impaired in APP/PS1 mice, although it did cause a significant increase in the area density of astrocytes in the granule cell layer across both genotypes. Finally, viral expression of sAPPα reduced amyloid-beta plaque load in APP/PS1 mice in the dentate gyrus and somatosensory cortex. These data add further evidence that increased levels of sAPPα could be therapeutic for the cognitive decline in AD, in part through restoration of the proliferation of neural progenitor cells in adults.
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Affiliation(s)
- Shane M Ohline
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand.,Department of Physiology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Connie Chan
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Lucia Schoderboeck
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Hollie E Wicky
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Warren P Tate
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Stephanie M Hughes
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
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22
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Collingridge GL, Abraham WC. Glutamate receptors and synaptic plasticity: The impact of Evans and Watkins. Neuropharmacology 2021; 206:108922. [PMID: 34919905 DOI: 10.1016/j.neuropharm.2021.108922] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/23/2021] [Accepted: 12/09/2021] [Indexed: 12/31/2022]
Abstract
On the occasion of the 40 year anniversary of the hugely impactful review by Richard (Dick) Evans and Jeff Watkins, we describe how their work has impacted the field of synaptic plasticity. We describe their influence in each of the major glutamate receptor subtypes: AMPARs, NMDARs, KARs and mGluRs. Particular emphasis is placed on how their work impacted our own studies in the hippocampus. For example, we describe how the tools and regulators that they identified for studying NMDARs (e.g., NMDA, D-AP5 and Mg2+) led to the understanding of the molecular basis of the induction of LTP. We also describe how other tools that they introduced (e.g., (1S,3R)-ACPD and MCPG) helped lead to the concept of metaplasticity.
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Affiliation(s)
- G L Collingridge
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, New Zealand; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada; TANZ Centre for Research in Neurodegenerative Diseases, Department of Physiology, University of Toronto, Toronto, ON, Canada.
| | - W C Abraham
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, New Zealand
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23
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Livingstone RW, Elder MK, Singh A, Westlake CM, Tate WP, Abraham WC, Williams JM. Secreted Amyloid Precursor Protein-Alpha Enhances LTP Through the Synthesis and Trafficking of Ca 2+-Permeable AMPA Receptors. Front Mol Neurosci 2021; 14:660208. [PMID: 33867938 PMCID: PMC8047154 DOI: 10.3389/fnmol.2021.660208] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/10/2021] [Indexed: 11/13/2022] Open
Abstract
Regulation of AMPA receptor expression by neuronal activity and neuromodulators is critical to the expression of both long-term potentiation (LTP) and memory. In particular, Ca2+-permeable AMPARs (CP-AMPAR) play a unique role in these processes due to their transient, activity-regulated expression at synapses. Secreted amyloid precursor protein-alpha (sAPPα), a metabolite of the parent amyloid precursor protein (APP) has been previously shown to enhance hippocampal LTP as well as memory formation in both normal animals and in Alzheimer’s disease models. In earlier work we showed that sAPPα promotes trafficking of GluA1-containing AMPARs to the cell surface and specifically enhances synthesis of GluA1. To date it is not known whether de novo synthesized GluA1 form CP-AMPARs or how they contribute to sAPPα-mediated plasticity. Here, using fluorescent non-canonical amino acid tagging–proximity ligation assay (FUNCAT-PLA), we show that brief treatment of primary rat hippocampal neurons with sAPPα (1 nM, 30 min) rapidly enhanced the cell-surface expression of de novo GluA1 homomers and reduced levels of de novo GluA2, as well as extant GluA2/3-AMPARs. The de novo GluA1-containing AMPARs were localized to extrasynaptic sites and later internalized by sAPPα-driven expression of the activity-regulated cytoskeletal-associated protein, Arc. Interestingly, longer exposure to sAPPα increased synaptic levels of GluA1/2 AMPARs. Moreover, the sAPPα-mediated enhancement of LTP in area CA1 of acute hippocampal slices was dependent on CP-AMPARs. Together, these findings show that sAPPα engages mechanisms which specifically enhance the synthesis and cell-surface expression of GluA1 homomers, underpinning the sAPPα-driven enhancement of synaptic plasticity in the hippocampus.
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Affiliation(s)
- Rhys W Livingstone
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Megan K Elder
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Anurag Singh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Courteney M Westlake
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Warren P Tate
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Joanna M Williams
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
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24
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Hegemann RU, Abraham WC. Postsynaptic cell firing triggers bidirectional metaplasticity depending on the LTP induction protocol. J Neurophysiol 2021; 125:1624-1635. [PMID: 33760659 DOI: 10.1152/jn.00514.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cell firing has been reported to variably upregulate or downregulate subsequently induced long-term potentiation (LTP). The aim of this study was to elucidate the parameters critical to driving each direction of the metaplasticity effect. The main focus was on the commonly used θ-burst stimulation (TBS) and high-frequency stimulation (HFS) protocols that are known to trigger distinct intracellular signaling cascades. To study action potential (AP)-induced metaplasticity, we used intracellular recordings from CA1 pyramidal cells of rat hippocampal slices. Somatic current injections were used to induce θ-burst firing (TBF) or high-frequency firing (HFF) for priming purposes, whereas LTP was induced 15 min later via TBS of Schaffer collaterals in stratum radiatum. TBS-LTP was inhibited by both priming protocols. Conversely, HFS-LTP was facilitated by HFF priming but not affected by TBF priming. Interestingly, both priming protocols reduced AP firing during TBS-LTP induction, and this effect correlated with the reduction of TBS-LTP. However, LTP was not rescued by restoring AP firing with somatic current injections during the TBS. Analysis of intrinsic properties revealed few changes, apart from a priming-induced increase in the medium afterhyperpolarization (HFF priming) and a decrease in the EPSP amplitude/slope ratio (TBF priming), which could in principle contribute to the inhibition of TBS-LTP by reducing depolarization and associated Ca2+ influx following synaptic activity or AP backpropagation. Overall, these data indicate that the more physiological TBS protocol for inducing LTP is particularly susceptible to homeostatic feedback inhibition by prior bouts of postsynaptic cell firing.NEW & NOTEWORTHY The induction of LTP in the hippocampus was bidirectionally regulated by prior postsynaptic cell firing, with θ-burst stimulation-induced LTP being consistently impaired by prior spiking, whereas high-frequency stimulation-induced LTP was either not changed or facilitated. Reductions in cell firing during LTP induction did not explain the LTP impairment. Overall, different patterns of postsynaptic firing induce distinct intracellular changes that can increase or decrease LTP depending on the induction protocol.
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Affiliation(s)
- Regina U Hegemann
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
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25
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Ryan M, Tan VTY, Thompson N, Guévremont D, Mockett BG, Tate WP, Abraham WC, Hughes SM, Williams J. Lentivirus-Mediated Expression of Human Secreted Amyloid Precursor Protein-Alpha Promotes Long-Term Induction of Neuroprotective Genes and Pathways in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2021; 79:1075-1090. [PMID: 33386801 DOI: 10.3233/jad-200757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Secreted amyloid precursor protein-alpha (sAPPα) can enhance memory and is neurotrophic and neuroprotective across a range of disease-associated insults, including amyloid-β toxicity. In a significant step toward validating sAPPα as a therapeutic for Alzheimer's disease (AD), we demonstrated that long-term overexpression of human sAPPα (for 8 months) in a mouse model of amyloidosis (APP/PS1) could prevent the behavioral and electrophysiological deficits that develop in these mice. OBJECTIVE To explore the underlying molecular mechanisms responsible for the significant physiological and behavioral improvements observed in sAPPα-treated APP/PS1 mice. METHODS We assessed the long-term effects on the hippocampal transcriptome following continuous lentiviral delivery of sAPPα or empty-vector to male APP/PS1 mice and wild-type controls using Affymetrix Mouse Transcriptome Assays. Data analysis was carried out within the Affymetrix Transcriptome Analysis Console and an integrated analysis of the resulting transcriptomic data was performed with Ingenuity Pathway analysis (IPA). RESULTS Mouse transcriptome assays revealed expected AD-associated gene expression changes in empty-vector APP/PS1 mice, providing validation of the assays used for the analysis. By contrast, there were specific sAPPα-associated gene expression profiles which included increases in key neuroprotective genes such as Decorin, betaine-GABA transporter and protocadherin beta-5, subsequently validated by qRT-PCR. An integrated biological pathways analysis highlighted regulation of GABA receptor signaling, cell survival and inflammatory responses. Furthermore, upstream gene regulatory analysis implicated sAPPα activation of Interleukin-4, which can counteract inflammatory changes in AD. CONCLUSION This study identified key molecular processes that likely underpin the long-term neuroprotective and therapeutic effects of increasing sAPPα levels in vivo.
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Affiliation(s)
- Margaret Ryan
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Valerie T Y Tan
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Nasya Thompson
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Diane Guévremont
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Bruce G Mockett
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Warren P Tate
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Stephanie M Hughes
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Joanna Williams
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
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26
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Kyrke-Smith M, Logan B, Abraham WC, Williams JM. Bilateral histone deacetylase 1 and 2 activity and enrichment at unique genes following induction of long-term potentiation in vivo. Hippocampus 2020; 31:389-407. [PMID: 33378103 DOI: 10.1002/hipo.23297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 12/15/2020] [Accepted: 12/19/2020] [Indexed: 11/10/2022]
Abstract
Long-term potentiation (LTP) is a synaptic plasticity mechanism critical to long-term memory. LTP induced in vivo is characterized by altered transcriptional activity, including a period of upregulation of gene expression which is followed by a later dominant downregulation. This temporal shift to downregulated gene expression is predicted to be partly mediated by epigenetic inhibitors of gene expression, such as histone deacetylases (HDACs). Further, pharmacological inhibitors of HDAC activity have previously been shown to enhance LTP persistence in vitro. To explore the contribution of HDACs to the persistence of LTP in vivo, we examined HDAC1 and HDAC2 activity over a 24 hr period following unilateral LTP induction in the dentate gyrus of freely moving rats. Surprisingly, we found significant changes in HDAC1 and HDAC2 activity in both the stimulated as well as the unstimulated hemispheres, with the largest increase in activity occurring bilaterally, 20 min after LTP stimulation. During this time point of heightened activity, chromatin immunoprecipitation assays showed that both HDAC1 and HDAC2 were enriched at distinct sets of genes within each hemispheres. Further, the HDAC inhibitor Trichostatin A enhanced an intermediate phase of LTP lasting days, which has not previously been associated with altered transcription. The inhibitor had no effect on the persistence of LTP lasting weeks. Together, these data suggest that HDAC activity early after the induction of LTP may negatively regulate plasticity-related gene expression that is involved in the initial stabilization of LTP, but not its long-term maintenance.
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Affiliation(s)
- Madeleine Kyrke-Smith
- Department of Anatomy, University of Otago, Dunedin, New Zealand.,Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Barbara Logan
- Department of Anatomy, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Anatomy, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Joanna M Williams
- Department of Anatomy, University of Otago, Dunedin, New Zealand.,Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
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27
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Reuben A, Elliott ML, Abraham WC, Broadbent J, Houts RM, Ireland D, Knodt AR, Poulton R, Ramrakha S, Hariri AR, Caspi A, Moffitt TE. Association of Childhood Lead Exposure With MRI Measurements of Structural Brain Integrity in Midlife. JAMA 2020; 324:1970-1979. [PMID: 33201203 PMCID: PMC7672511 DOI: 10.1001/jama.2020.19998] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
IMPORTANCE Childhood lead exposure has been linked to disrupted brain development, but long-term consequences for structural brain integrity are unknown. OBJECTIVE To test the hypothesis that childhood lead exposure is associated with magnetic resonance imaging (MRI) measurements of lower structural integrity of the brain in midlife. DESIGN, SETTING, AND PARTICIPANTS The Dunedin Study followed a population-representative 1972-1973 birth cohort in New Zealand (N = 564 analytic sample) to age 45 years (until April 2019). EXPOSURES Childhood blood lead levels measured at age 11 years. MAIN OUTCOMES AND MEASURES Structural brain integrity at age 45 years assessed via MRI (primary outcomes): gray matter (cortical thickness, surface area, hippocampal volume), white matter (white matter hyperintensities, fractional anisotropy [theoretical range, 0 {diffusion is perfectly isotropic} to 100 {diffusion is perfectly anisotropic}]), and the Brain Age Gap Estimation (BrainAGE), a composite index of the gap between chronological age and a machine learning algorithm-estimated brain age (0 indicates a brain age equivalent to chronological age; positive and negative values represent an older and younger brain age, respectively). Cognitive function at age 45 years was assessed objectively via the Wechsler Adult Intelligence Scale IV (IQ range, 40-160, standardized to a mean of 100 [SD, 15]) and subjectively via informant and self-reports (z-score units; scale mean, 0 [SD, 1]). RESULTS Of 1037 original participants, 997 were alive at age 45 years, of whom 564 (57%) had received lead testing at age 11 years (302 [54%] male) (median follow-up, 34 [interquartile range, 33.7-34.7] years). Mean blood lead level at age 11 years was 10.99 (SD, 4.63) μg/dL. After adjusting for covariates, each 5-μg/dL higher childhood blood lead level was significantly associated with 1.19-cm2 smaller cortical surface area (95% CI, -2.35 to -0.02 cm2; P = .05), 0.10-cm3 smaller hippocampal volume (95% CI, -0.17 to -0.03 cm3; P = .006), lower global fractional anisotropy (b = -0.12; 95% CI, -0.24 to -0.01; P = .04), and a BrainAGE index 0.77 years older (95% CI, 0.02-1.51 years; P = .05) at age 45 years. There were no statistically significant associations between blood lead level and log-transformed white matter hyperintensity volume (b = 0.05 log mm3; 95% CI, -0.02 to 0.13 log mm3; P = .17) or mean cortical thickness (b = -0.004 mm; 95% CI, -0.012 to 0.004 mm; P = .39). Each 5-μg/dL higher childhood blood lead level was significantly associated with a 2.07-point lower IQ score at age 45 years (95% CI, -3.39 to -0.74; P = .002) and a 0.12-point higher score on informant-rated cognitive problems (95% CI, 0.01-0.23; P = .03). There was no statistically significant association between childhood blood lead levels and self-reported cognitive problems (b = -0.02 points; 95% CI, -0.10 to 0.07; P = .68). CONCLUSIONS AND RELEVANCE In this longitudinal cohort study with a median 34-year follow-up, higher childhood blood lead level was associated with differences in some MRI measures of brain structure that suggested lower structural brain integrity in midlife. Because of the large number of statistical comparisons, some findings may represent type I error.
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Affiliation(s)
- Aaron Reuben
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
| | - Maxwell L. Elliott
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
| | - Wickliffe C. Abraham
- Brain Health Research Centre, Brain Research New Zealand, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Jonathan Broadbent
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Renate M. Houts
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
| | - David Ireland
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Annchen R. Knodt
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
| | - Richie Poulton
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Sandhya Ramrakha
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Ahmad R. Hariri
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
| | - Avshalom Caspi
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, North Carolina
- Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, England
- PROMENTA, Department of Psychology, University of Oslo, Oslo, Norway
| | - Terrie E. Moffitt
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, North Carolina
- Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, England
- PROMENTA, Department of Psychology, University of Oslo, Oslo, Norway
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Chiamulera C, Piva A, Abraham WC. Glutamate receptors and metaplasticity in addiction. Curr Opin Pharmacol 2020; 56:39-45. [PMID: 33128937 DOI: 10.1016/j.coph.2020.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 12/12/2022]
Abstract
Chronic drug use is a neuroadaptive disorder characterized by strong and persistent plasticity in the mesocorticolimbic reward system. Long-lasting effects of drugs of abuse rely on their ability to hijack glutamate receptor activity and long-term synaptic plasticity processes like long-term potentiation and depression. Importantly, metaplasticity-based modulation of synaptic plasticity contributes to durable neurotransmission changes in mesocorticolimbic pathways including the ventral tegmental area and the nucleus accumbens, causing 'maladaptive' drug memory and higher risk for drug-seeking relapse. On the other hand, drug-induced metaplasticity can make appetitive memories more malleable to modification, offering a potential target mechanism for intervention. Here we review the literature on the role of glutamate receptors in addiction-related metaplasticity phenomena.
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Affiliation(s)
- Cristiano Chiamulera
- Neuropsychopharmacology Lab, Section Pharmacology, Department Diagnostic & Public Health, University of Verona, Verona, Italy.
| | - Alessandro Piva
- Neuropsychopharmacology Lab, Section Pharmacology, Department Diagnostic & Public Health, University of Verona, Verona, Italy
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
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Mathiesen SN, Lock JL, Schoderboeck L, Abraham WC, Hughes SM. CNS Transduction Benefits of AAV-PHP.eB over AAV9 Are Dependent on Administration Route and Mouse Strain. Mol Ther Methods Clin Dev 2020; 19:447-458. [PMID: 33294493 PMCID: PMC7683292 DOI: 10.1016/j.omtm.2020.10.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/06/2020] [Indexed: 11/18/2022]
Abstract
Adeno-associated viral (AAV) vectors are attractive tools for central nervous system (CNS) gene therapy because some vectors can cross the blood-brain barrier (BBB), allowing them to be used as minimally invasive treatments. A novel AAV vector recently evolved in vivo, AAV-PHP.eB, has been reported to cross the BBB more effectively than the existing gold standard AAV9, but not under all conditions. Here, we compared the efficacy of single-stranded AAV-PHP.eB and AAV9 in targeting mouse CNS and peripheral tissues after administration via various routes, in two different mouse strains (C57BL/6J and B6C3), and after packaging AAV-PHP.eB with a self-complementary genome. We found that AAV-PHP.eB produced higher CNS transduction than AAV9 after intravenous injection, but only in C57BL/6J and not in B6C3 mice. AAV-PHP.eB and AAV9 produced similar CNS transduction when the administration route did not require the vectors to cross the BBB. Packaging AAV-PHP.eB with a self-complementary genome increased overall CNS transduction, but at the expense of strong neuronal tropism. AAV-PHP.eB resulted in less transduction of liver tissue than AAV9 under all conditions. Taken together, these results suggest the potential for AAV-PHP.eB as a vector for CNS gene therapy applications, but consideration will be required for translation beyond mouse models.
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Affiliation(s)
- Sophie N Mathiesen
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin 9016, New Zealand.,Department of Psychology, Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin 9016, New Zealand
| | - Jasmine L Lock
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin 9016, New Zealand
| | - Lucia Schoderboeck
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin 9016, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin 9016, New Zealand
| | - Stephanie M Hughes
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand-Rangahau Roro Aotearoa, University of Otago, Dunedin 9016, New Zealand
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30
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Affiliation(s)
- Shruthi Sateesh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Wickliffe C. Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
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31
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Morrissey JA, Bigus E, Necarsulmer JC, Srinivasan V, Peppercorn K, O'Leary DJ, Mockett BG, Tate WP, Hughes SM, Parfitt KD, Abraham WC. The Tripeptide RER Mimics Secreted Amyloid Precursor Protein-Alpha in Upregulating LTP. Front Cell Neurosci 2019; 13:459. [PMID: 31680870 PMCID: PMC6813913 DOI: 10.3389/fncel.2019.00459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 09/26/2019] [Indexed: 12/15/2022] Open
Abstract
Secreted amyloid precursor protein-alpha (sAPPα), generated by enzymatic processing of the APP, possesses a range of neurotrophic and neuroprotective properties and plays a critical role in the molecular mechanisms of memory and learning. One of the key active regions of sAPPα is the central APP domain (E2) that contains within it the tripeptide sequence, RER. This sequence is exposed on the surface of a coiled coil substructure of E2. RER has by itself displayed memory-enhancing properties, and can protect newly formed engrams from interference in a manner similar to that displayed by sAPPα itself. In order to determine whether RER mimics other properties of sAPPα, we investigated the electrophysiological effects of the N-terminal protected acetylated RER (Ac-RER) and an isoform containing a chiral switch in the first amino acid from an l- to a d-orientation (Ac-rER), on synaptic plasticity. We found that, like sAPPα, exogenous perfusion with nanomolar concentrations of Ac-RER or Ac-rER enhanced the induction and stability of long-term potentiation (LTP) in area CA1 of rat and mouse hippocampal slices, in a protein synthesis- and trafficking-dependent manner. This effect did not occur with a control Ac-AAA or Ac-IFR tripeptide, nor with a full-length sAPPα protein where RER was substituted with AAA. Ac-rER also protected LTP against amyloid-beta (Aβ25–35)-induced LTP impairment. Our findings provide further evidence that the RER-containing region of sAPPα is functionally significant and by itself can produce effects similar to those displayed by full length sAPPα, suggesting that this tripeptide, like sAPPα, may have therapeutic potential.
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Affiliation(s)
- Jodi A Morrissey
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand.,Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Erin Bigus
- Department of Neuroscience, Pomona College, Claremont, CA, United States
| | | | - Vinay Srinivasan
- Department of Neuroscience, Pomona College, Claremont, CA, United States
| | - Katie Peppercorn
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Daniel J O'Leary
- Department of Neuroscience, Pomona College, Claremont, CA, United States
| | - Bruce G Mockett
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Warren P Tate
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Stephanie M Hughes
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Karen D Parfitt
- Department of Neuroscience, Pomona College, Claremont, CA, United States
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
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Ryan MM, Guévremont D, Mockett BG, Abraham WC, Williams JM. Circulating Plasma microRNAs are Altered with Amyloidosis in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2019; 66:835-852. [PMID: 30347618 DOI: 10.3233/jad-180385] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pathological changes underlying Alzheimer's disease (AD) begin decades before the classical symptoms of memory loss become evident. As microRNAs are released from neurons and enter the bloodstream, circulating microRNAs may be reflective of AD progression and are ideal candidates as biomarkers for early-stage disease detection. Here, we provide a novel, in-depth analysis of how plasma microRNAs alter with aging, the most prominent risk factor for AD, and with development of amyloid-β (Aβ) plaque deposition. We assessed the circulating microRNAs in APPswe/PSEN1dE9 transgenic mice and wild-type controls at 4, 8 and 15 m (n = 8-10) using custom designed Taqman arrays representing 185 neuropathology-related microRNAs. We performed a linear mixed-effects model to investigate the effects of age and genotype on plasma microRNAs expression. Following this analysis, we found 8 microRNAs were significantly affected by age alone in wild-type animals and 12 microRNAs altered in APPswe/PSEN1dE9 mice, either prior to Aβ plaque deposition (4 m) or during the development of AD-like pathogenesis (8 m or 15 m). Importantly, we found that differing sets of microRNAs were identified at each time point. Functional analysis of these data revealed that while common biological pathways, such as Inflammatory Response, were enriched throughout the disease process, Free Radical Scavenging, Immunological Disease, and Apoptosis Signaling were specifically enriched later in the disease process. Overall, this study reinforces that distinct biological processes underpin the early versus late stages of AD-like pathogenesis and highlights potential pre-symptomatic microRNAs biomarkers of neurodegeneration.
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Affiliation(s)
- Margaret M Ryan
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Diane Guévremont
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Bruce G Mockett
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Joanna M Williams
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre, Brain Research New Zealand - Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
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33
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Affiliation(s)
- Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Gal Richter-Levin
- Sagol Department of Neuroscience, Department of Psychology, The Integrated Brain & Behavior Researcher Center, University of Haifa, Haifa, Israel
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34
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Bergin DH, Jing Y, Williams G, Mockett BG, Zhang H, Abraham WC, Liu P. Safety and neurochemical profiles of acute and sub-chronic oral treatment with agmatine sulfate. Sci Rep 2019; 9:12669. [PMID: 31481723 PMCID: PMC6722093 DOI: 10.1038/s41598-019-49078-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 08/19/2019] [Indexed: 01/25/2023] Open
Abstract
Agmatine (decarboxylated arginine) exerts numerous central nervous system (CNS) dependent pharmacological effects and may potentially modulate altered neurochemistry seen in neurological disorders. In preclinical studies, injection has been the predominant route of systemic administration. However, a significant translational step would be the use of oral agmatine treatment at therapeutic doses and better understanding of L-arginine metabolic profiles in the CNS post-treatment. The present study systematically investigated the tolerability, safety and brain-plasma neurochemistry following daily oral agmatine sulfate treatment (via gavage) to wild-type (WT) mice up to 900 mg/kg for one week (Experiment 1) or WT and APPswe/PS1ΔE9 transgenic (Tg) mice at 300 mg/kg for fifteen weeks (Experiment 2). Agmatine treatment in both experiments was well tolerated with no marked behavioural impairments, and gross necropsy and organ histology revealed no pathological alterations after 15-week dosing. Moreover, oral treatment increased agmatine levels in the hippocampus and plasma of WT mice (Experiment 1), and in 6 brain regions examined (but not plasma) of WT and Tg mice (Experiment 2), at 30 minutes or 24 hours post-treatment respectively. This study provides fundamental pre-clinical evidence that daily oral delivery of agmatine sulfate to both WT and Tg mice is safe and well tolerated. Exogenous agmatine passes through the blood brain barrier and accumulates in the brain to a greater extent in Tg mice. Furthermore exogenous agmatine has differential actions in the brain and periphery, and its effect on brain putrescine appears to be dependent on the time post-treatment.
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Affiliation(s)
- David H Bergin
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand.,School of Pharmacy, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Yu Jing
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Gail Williams
- Department of Pathology, University of Otago, Dunedin, New Zealand
| | - Bruce G Mockett
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Hu Zhang
- School of Pharmacy, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Ping Liu
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
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35
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Livingstone RW, Elder MK, Barrett MC, Westlake CM, Peppercorn K, Tate WP, Abraham WC, Williams JM. Secreted Amyloid Precursor Protein-Alpha Promotes Arc Protein Synthesis in Hippocampal Neurons. Front Mol Neurosci 2019; 12:198. [PMID: 31474829 PMCID: PMC6702288 DOI: 10.3389/fnmol.2019.00198] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/30/2019] [Indexed: 12/22/2022] Open
Abstract
Secreted amyloid precursor protein-α (sAPPα) is a neuroprotective and memory-enhancing molecule, however, the mechanisms through which sAPPα promotes these effects are not well understood. Recently, we have shown that sAPPα enhances cell-surface expression of glutamate receptors. Activity-related cytoskeletal-associated protein Arc (Arg3.1) is an immediate early gene capable of modulating long-term potentiation, long-term depression and homeostatic plasticity through regulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor localization. Accordingly, we hypothesized that sAPPα may enhance synaptic plasticity, in part, by the de novo synthesis of Arc. Using primary cortical and hippocampal neuronal cultures we found that sAPPα (1 nM, 2 h) enhances levels of Arc mRNA and protein. Arc protein levels were increased in both the neuronal somata and dendrites in a Ca2+/calmodulin-dependent protein kinase II-dependent manner. Additionally, dendritic Arc expression was dependent upon activation of mitogen-activated protein kinase and protein kinase G. The enhancement of dendritic Arc protein was significantly reduced by antagonism of N-methyl-D-aspartate (NMDA) and nicotinic acetylcholine (α7nACh) receptors, and fully eliminated by dual application of these antagonists. This effect was further corroborated in area CA1 of acute hippocampal slices. These data suggest sAPPα-regulated plasticity within hippocampal neurons is mediated by cooperation of NMDA and α7nACh receptors to engage a cascade of signal transduction molecules to enhance the transcription and translation of Arc.
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Affiliation(s)
- Rhys W Livingstone
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Megan K Elder
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Maya C Barrett
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Courteney M Westlake
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Katie Peppercorn
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Warren P Tate
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Joanna M Williams
- Department of Anatomy, Brain Health Research Centre, Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
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36
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Morrissey JA, Mockett BG, Singh A, Kweon D, Ohline SM, Tate WP, Hughes SM, Abraham WC. A C-terminal peptide from secreted amyloid precursor protein-α enhances long-term potentiation in rats and a transgenic mouse model of Alzheimer's disease. Neuropharmacology 2019; 157:107670. [PMID: 31202608 DOI: 10.1016/j.neuropharm.2019.107670] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 05/05/2019] [Accepted: 06/12/2019] [Indexed: 01/20/2023]
Abstract
Processing of the amyloid precursor protein by alternative secretases results in ectodomain shedding of either secreted amyloid precursor protein-α (sAPPα) or its counterpart secreted amyloid precursor protein-β (sAPPβ). Although sAPPα contains only 16 additional amino acids at its C-terminus compared to sAPPβ, it displays significantly greater potency in neuroprotection, neurotrophism and enhancement of long-term potentiation (LTP). In the current study, this 16 amino acid peptide sequence (CTα16) was characterised for its ability to replicate the synaptic plasticity-enhancing properties of sAPPα. An N-acetylated version of CTα16 produced concentration-dependent increases in the induction and persistence of LTP at Schaffer collateral/commissural synapses in area CA1 of young adult rat hippocampal slices. A scrambled peptide had no effect. CTα16 significantly enhanced de novo protein synthesis, and correspondingly its enhancement of LTP was blocked by the protein synthesis inhibitor cycloheximide, as well as by the α7-nicotinic receptor blocker α-bungarotoxin. The impaired LTP of 14-16 month old APPswe/PS1dE9 transgenic mice, a mouse model of Alzheimer's disease, was completely restored to the wild-type level by CTα16. These results indicate that the CTα16 peptide fragment of sAPPα mimics the larger protein's functionality with respect to LTP, stimulation of protein synthesis and activation of α7-nAChRs, and thus like sAPPα may have potential as a therapeutic agent against the plasticity and cognitive deficits observed in AD and other neurological disorders.
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Affiliation(s)
- Jodi A Morrissey
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand; Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Bruce G Mockett
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Anurag Singh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - David Kweon
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Shane M Ohline
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Warren P Tate
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Stephanie M Hughes
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
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37
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Abstract
Metabotropic glutamate receptors (mGluRs) are one of the major types of glutamatergic receptors contributing to synaptic plasticity mechanisms such as long-term potentiation (LTP) and long-term depression. Interestingly, activation of mGluRs alone can engage metaplastic mechanisms that create a new neuronal state, facilitating the induction and maintenance of future LTP. Here we describe typical methods used to investigate mGluR-induced metaplasticity in acute hippocampal slices. While this chapter focuses on in vitro field electrophysiological investigations, many of the principles can be applied to single-cell recordings as well as in vivo electrophysiology and indeed many types of metaplasticity phenomena.
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Affiliation(s)
- Regina U Hegemann
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
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38
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Abraham WC, Jones OD, Glanzman DL. Is plasticity of synapses the mechanism of long-term memory storage? NPJ Sci Learn 2019; 4:9. [PMID: 31285847 PMCID: PMC6606636 DOI: 10.1038/s41539-019-0048-y] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/29/2019] [Indexed: 05/05/2023]
Abstract
It has been 70 years since Donald Hebb published his formalized theory of synaptic adaptation during learning. Hebb's seminal work foreshadowed some of the great neuroscientific discoveries of the following decades, including the discovery of long-term potentiation and other lasting forms of synaptic plasticity, and more recently the residence of memories in synaptically connected neuronal assemblies. Our understanding of the processes underlying learning and memory has been dominated by the view that synapses are the principal site of information storage in the brain. This view has received substantial support from research in several model systems, with the vast majority of studies on the topic corroborating a role for synapses in memory storage. Yet, despite the neuroscience community's best efforts, we are still without conclusive proof that memories reside at synapses. Furthermore, an increasing number of non-synaptic mechanisms have emerged that are also capable of acting as memory substrates. In this review, we address the key findings from the synaptic plasticity literature that make these phenomena such attractive memory mechanisms. We then turn our attention to evidence that questions the reliance of memory exclusively on changes at the synapse and attempt to integrate these opposing views.
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Affiliation(s)
- Wickliffe C. Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9010 New Zealand
| | - Owen D. Jones
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9010 New Zealand
| | - David L. Glanzman
- Departments of Integrative Biology and Physiology, and Neurobiology, and the Brain Research Institute, University of California, Los Angeles, CA 90095 USA
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39
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Schoderboeck L, Wicky HE, Abraham WC, Hughes SM. Genetic Targeting and Chemogenetic Inhibition of Newborn Neurons. Hum Gene Ther Methods 2018; 29:259-268. [PMID: 30526082 DOI: 10.1089/hgtb.2018.182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aim of this study was to develop a method to silence a very specific set of cells in a spatially and temporally refined manner. Here, an approach is presented that combines the use of a transgenic mouse line, expressing cre recombinase under a nestin promoter, with lentiviral delivery of a floxed, ivermectin (IVM)-gated chloride channel construct to the dentate gyrus. This approach was used to express an IVM-sensitive chloride channel in newly born granule cells in adult mouse brains, and its ability to silence neuronal activity was tested by analyzing the effect on immediate early gene expression in vitro in cre-transgenic primary neuronal cultures. IVM treatment of cells expressing the chloride channel prevented gabazine-induced expression of the immediate early gene product EGR1, while cells expressing a control inactive channel or no channel retained their EGR1 response. Thus, a genetic strategy is presented for targeting a specific neurogenic niche for transgene expression in the adult mouse brain, and proof of principle is shown that it can be used in vitro as a method for silencing neuronal activity.
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Affiliation(s)
- Lucia Schoderboeck
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, and University of Otago, Dunedin, New Zealand.,Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Hollie E Wicky
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, and University of Otago, Dunedin, New Zealand.,Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, and University of Otago, Dunedin, New Zealand
| | - Stephanie M Hughes
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, and University of Otago, Dunedin, New Zealand.,Genetics Otago, University of Otago, Dunedin, New Zealand
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40
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Ulrich K, Spriggs MJ, Abraham WC, Dalrymple-Alford JC, McNaughton N. Environmental enrichment increases prefrontal EEG power and synchrony with the hippocampus in rats with anterior thalamus lesions. Hippocampus 2018; 29:128-140. [PMID: 30153381 DOI: 10.1002/hipo.23022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 07/11/2018] [Accepted: 08/14/2018] [Indexed: 11/12/2022]
Abstract
The anterior thalamic nuclei (ATN) are a major interface between the hippocampus and prefrontal cortex within an extended Papez circuit. Rat models suggest that the deficits caused by ATN damage, which is associated with "diencephalic amnesia", can be ameliorated by environmental enrichment (EE) through unknown mechanisms. We examined whether changes in theta rhythmicity within and between the hippocampus and prefrontal cortex are influenced by EE in rats with ATN lesions. Here, we show that ATN lesions and EE produced essentially opposed functional effects in terms of changes in rhythmicity between two consecutive trials when rats forage for chocolate hail. On the second trial, standard-housed rats with ATN lesions showed: (a) a clear reduction in prefrontal cortex experience-dependent power change in the theta band and in two adjacent bands; (b) little change in the theta band in hippocampal area CA1; and (c) only a modest overall reduction in experience-dependent power change at lower theta frequencies in the dentate gyrus. EE exposure prevented the decrease in prefrontal theta power in rats with ATN lesions, and in fact caused a clear increase in prefrontal cortex power across all bands. While ATN lesions did not reliably affect prefrontal-CA1 or prefrontal-dentate theta coherence, EE increased the coherence between prefrontal cortex and area CA1 in both the sham and ATN groups. Thus, EE increases functional connectivity between prefrontal cortex and hippocampus via pathways that bypass the ATN, and increases behaviorally dependent prefrontal rhythmicity. These EEG effects may contribute to improved learning and memory in the ATN-lesion model of diencephalic amnesia.
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Affiliation(s)
- Katharina Ulrich
- Department of Psychology and Brain Health Research Center, University of Otago, Dunedin, New Zealand
| | - Megg J Spriggs
- Department of Psychology, Brain Health Research Center, and Brain Research New Zealand, University of Otago, Dunedin, New Zealand.,School of Psychology, and Brain Research New Zealand, University of Auckland, Auckland, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Center, and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - John C Dalrymple-Alford
- Department of Psychology, New Zealand Brain Research Institute and Brain Research New Zealand, University of Canterbury, Ilam, Christchurch, New Zealand
| | - Neil McNaughton
- Department of Psychology and Brain Health Research Center, University of Otago, Dunedin, New Zealand
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41
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Bergin DH, Jing Y, Mockett BG, Zhang H, Abraham WC, Liu P. Altered plasma arginine metabolome precedes behavioural and brain arginine metabolomic profile changes in the APPswe/PS1ΔE9 mouse model of Alzheimer's disease. Transl Psychiatry 2018; 8:108. [PMID: 29802260 PMCID: PMC5970225 DOI: 10.1038/s41398-018-0149-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 02/21/2018] [Accepted: 04/04/2018] [Indexed: 11/09/2022] Open
Abstract
While amyloid-beta (Aβ) peptides play a central role in the development of Alzheimer's disease (AD), recent evidence also implicates altered metabolism of L-arginine in the pathogenesis of AD. The present study systematically investigated how behavioural function and the brain and plasma arginine metabolic profiles changed in a chronic Aβ accumulation model using male APPswe/PS1ΔE9 transgenic (Tg) mice at 7 and 13 months of age. As compared to their wild-type (WT) littermates, Tg mice displayed age-related deficits in spatial water maze tasks and alterations in brain arginine metabolism. Interestingly, the plasma arginine metabolic profile was markedly altered in 7-month Tg mice prior to major behavioural impairment. Receiver operating characteristic curve analysis revealed that plasma putrescine and spermine significantly differentiated between Tg and WT mice. These results demonstrate the parallel development of altered brain arginine metabolism and behavioural deficits in Tg mice. The altered plasma arginine metabolic profile that preceded the behavioural and brain profile changes suggests that there may be merit in an arginine-centric set of ante-mortem biomarkers for AD.
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Affiliation(s)
- D H Bergin
- Department of Anatomy, University of Otago, Dunedin, New Zealand
- School of Pharmacy, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Y Jing
- Department of Anatomy, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - B G Mockett
- Brain Research New Zealand and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - H Zhang
- School of Pharmacy, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - W C Abraham
- Brain Research New Zealand and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - P Liu
- Department of Anatomy, University of Otago, Dunedin, New Zealand.
- Brain Research New Zealand and Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
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42
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Ohline SM, Wake KL, Hawkridge MV, Dinnunhan MF, Hegemann RU, Wilson A, Schoderboeck L, Logan BJ, Jungenitz T, Schwarzacher SW, Hughes SM, Abraham WC. Adult-born dentate granule cell excitability depends on the interaction of neuron age, ontogenetic age and experience. Brain Struct Funct 2018; 223:3213-3228. [PMID: 29796923 DOI: 10.1007/s00429-018-1685-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 05/15/2018] [Indexed: 12/11/2022]
Abstract
Early during their maturation, adult-born dentate granule cells (aDGCs) are particularly excitable, but eventually develop the electrophysiologically quiet properties of mature cells. However, the stability versus plasticity of this quiet state across time and experience remains unresolved. By birthdating two populations of aDGCs across different animal ages, we found for 10-month-old rats the expected reduction in excitability across cells aged 4-12 weeks, as determined by Egr1 immunoreactivity. Unexpectedly, cells 35 weeks old (after genesis at an animal age of 2 months) were as excitable as 4-week-old cells, in the dorsal hippocampus. This high level of excitability at maturity was specific for cells born in animals 2 months of age, as cells born later in life did not show this effect. Importantly, excitability states were not fixed once maturity was gained, but were enhanced by enriched environment exposure or LTP induction, indicating that any maturational decrease in excitability can be compensated by experience. These data reveal the importance of the animal's age for aDGC excitability, and emphasize their prolonged capability for plasticity during adulthood.
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Affiliation(s)
- S M Ohline
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - K L Wake
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - M-V Hawkridge
- Institute of Clinical Neuroanatomy, Goethe-University of Frankfurt, Frankfurt am Main, Germany
| | - M F Dinnunhan
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - R U Hegemann
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - A Wilson
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - L Schoderboeck
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Department of Biochemistry, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - B J Logan
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - T Jungenitz
- Institute of Clinical Neuroanatomy, Goethe-University of Frankfurt, Frankfurt am Main, Germany
| | - S W Schwarzacher
- Institute of Clinical Neuroanatomy, Goethe-University of Frankfurt, Frankfurt am Main, Germany
| | - S M Hughes
- Department of Biochemistry, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - W C Abraham
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand. .,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
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43
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Ohline SM, Abraham WC. Environmental enrichment effects on synaptic and cellular physiology of hippocampal neurons. Neuropharmacology 2018; 145:3-12. [PMID: 29634984 DOI: 10.1016/j.neuropharm.2018.04.007] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 12/21/2022]
Abstract
Exposure of rodents to an enriched environment (EE) has been shown to reliably increase performance on hippocampus-dependent learning and memory tasks, compared to conspecifics living in standard housing conditions. Here we review the EE-related functional changes in synaptic and cellular properties for neurons in the dentate gyrus and area CA1, as assessed through in vivo and ex vivo electrophysiological approaches. There is a growing consensus of findings regarding the pattern of effects seen. Most prominently, there are changes in cellular excitability and synaptic plasticity in CA1, particularly with short-term and/or periodic exposure to EE. Such changes are much less evident after longer term continuous exposure to EE. In the dentate gyrus, increases in synaptic transmission as well as cell excitability become evident after short-term EE exposure, while the induction of long-term potentiation (LTP) in the dentate is remarkably insensitive, even though it is reliably enhanced by voluntary running. Recent evidence has added a new dimension to the understanding of EE effects on hippocampal electrophysiology by revealing an increased sparsity of place cell representations after long periods of EE treatment. It is possible that such connectivity change is one of the key factors contributing to the enhancement of hippocampus-dependent spatial learning over the long-term, even if there are no obvious changes in other markers such as LTP. This article is part of the Special Issue entitled "Neurobiology of Environmental Enrichment".
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Affiliation(s)
- S M Ohline
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, New Zealand
| | - W C Abraham
- Department of Psychology, Brain Health Research Centre and Brain Research New Zealand, University of Otago, New Zealand.
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44
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Tan VTY, Mockett BG, Ohline SM, Parfitt KD, Wicky HE, Peppercorn K, Schoderboeck L, Yahaya MFB, Tate WP, Hughes SM, Abraham WC. Lentivirus-mediated expression of human secreted amyloid precursor protein-alpha prevents development of memory and plasticity deficits in a mouse model of Alzheimer's disease. Mol Brain 2018; 11:7. [PMID: 29426354 PMCID: PMC5806250 DOI: 10.1186/s13041-018-0348-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/16/2018] [Indexed: 02/08/2023] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease driven in large part by accumulated deposits in the brain of the amyloid precursor protein (APP) cleavage product amyloid-β peptide (Aβ). However, AD is also characterised by reductions in secreted amyloid precursor protein-alpha (sAPPα), an alternative cleavage product of APP. In contrast to the neurotoxicity of accumulated Αβ, sAPPα has many neuroprotective and neurotrophic properties. Increasing sAPPα levels has the potential to serve as a therapeutic treatment that mitigates the effects of Aβ and rescue cognitive function. Here we tested the hypothesis that lentivirus-mediated expression of a human sAPPα construct in a mouse model of AD (APPswe/PS1dE9), begun before the onset of plaque pathology, could prevent later behavioural and electrophysiological deficits. Male mice were given bilateral intra-hippocampal injections at 4 months of age and tested 8–10 months later. Transgenic mice expressing sAPPα performed significantly better than untreated littermates in all aspects of the spatial water maze task. Expression of sAPPα also resulted in partial rescue of long-term potentiation (LTP), tested in vitro. These improvements occurred in the absence of changes in amyloid pathology. Supporting these findings on LTP, lentiviral-mediated expression of sAPPα for 3 months from 10 months of age, or acute sAPPα treatment in hippocampal slices from 18 to 20 months old transgenic mice, completely reversed the deficits in LTP. Together these findings suggest that sAPPα has wide potential to act as either a preventative or restorative therapeutic treatment in AD by mitigating the effects of Aβ toxicity and enhancing cognitive reserve.
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Affiliation(s)
- Valerie T Y Tan
- Department of Psychology, University of Otago, Box 56, Dunedin, 9054, New Zealand.,Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Bruce G Mockett
- Department of Psychology, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Shane M Ohline
- Department of Psychology, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Karen D Parfitt
- Department of Neuroscience, Pomona College, Claremont, California, 91711, USA
| | - Hollie E Wicky
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Katie Peppercorn
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Lucia Schoderboeck
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Mohamad Fairuz Bin Yahaya
- Department of Psychology, University of Otago, Box 56, Dunedin, 9054, New Zealand.,Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Warren P Tate
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Stephanie M Hughes
- Department of Biochemistry, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, University of Otago, Box 56, Dunedin, 9054, New Zealand.
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45
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Bilkey DK, Cheyne KR, Eckert MJ, Lu X, Chowdhury S, Worley PF, Crandall JE, Abraham WC. Exposure to complex environments results in more sparse representations of space in the hippocampus. Hippocampus 2017; 27:1178-1191. [PMID: 28686801 PMCID: PMC5752118 DOI: 10.1002/hipo.22762] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/30/2017] [Accepted: 06/27/2017] [Indexed: 12/27/2022]
Abstract
The neural circuitry mediating sensory and motor representations is adaptively tuned by an animal's interaction with its environment. Similarly, higher order representations such as spatial memories can be modified by exposure to a complex environment (CE), but in this case the changes in brain circuitry that mediate the effect are less well understood. Here, we show that prolonged CE exposure was associated with increased selectivity of CA1 "place cells" to a particular recording arena compared to a social control (SC) group. Furthermore, fewer CA1 and DG neurons in the CE group expressed high levels of Arc protein, a marker of recent activation, following brief exposure to a completely novel environment. The reduced Arc expression was not attributable to overall changes in cell density or number. These data indicate that one effect of CE exposure is to modify high-level spatial representations in the brain by increasing the sparsity of population coding within networks of neurons. Greater sparsity could result in a more efficient and compact coding system that might alter behavioural performance on spatial tasks. The results from a behavioural experiment were consistent with this hypothesis, as CE-treated animals habituated more rapidly to a novel environment despite showing equivalent initial responding.
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Affiliation(s)
- David K. Bilkey
- Department of Psychology and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Kirsten R. Cheyne
- Department of Psychology and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Michael J. Eckert
- Department of Psychology and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Xiaodong Lu
- Department of Psychology and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Shoaib Chowdhury
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe St, Baltimore, MD 21205, USA
| | - Paul F. Worley
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe St, Baltimore, MD 21205, USA
| | - James E. Crandall
- Eunice Kennedy Shriver Center, University of Massachusetts Medical School Waltham, MA 02452, USA
| | - Wickliffe C. Abraham
- Department of Psychology and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
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Fisher SD, Robertson PB, Black MJ, Redgrave P, Sagar MA, Abraham WC, Reynolds JNJ. Reinforcement determines the timing dependence of corticostriatal synaptic plasticity in vivo. Nat Commun 2017; 8:334. [PMID: 28839128 PMCID: PMC5571189 DOI: 10.1038/s41467-017-00394-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 06/26/2017] [Indexed: 12/21/2022] Open
Abstract
Plasticity at synapses between the cortex and striatum is considered critical for learning novel actions. However, investigations of spike-timing-dependent plasticity (STDP) at these synapses have been performed largely in brain slice preparations, without consideration of physiological reinforcement signals. This has led to conflicting findings, and hampered the ability to relate neural plasticity to behavior. Using intracellular striatal recordings in intact rats, we show here that pairing presynaptic and postsynaptic activity induces robust Hebbian bidirectional plasticity, dependent on dopamine and adenosine signaling. Such plasticity, however, requires the arrival of a reward-conditioned sensory reinforcement signal within 2 s of the STDP pairing, thus revealing a timing-dependent eligibility trace on which reinforcement operates. These observations are validated with both computational modeling and behavioral testing. Our results indicate that Hebbian corticostriatal plasticity can be induced by classical reinforcement learning mechanisms, and might be central to the acquisition of novel actions. Spike timing dependent plasticity (STDP) has been studied extensively in slices but whether such pairings can induce plasticity in vivo is not known. Here the authors report an experimental paradigm that achieves bidirectional corticostriatal STDP in vivo through modulation by behaviourally relevant reinforcement signals, mediated by dopamine and adenosine signaling.
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Affiliation(s)
- Simon D Fisher
- Department of Anatomy and the Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, 9054, New Zealand
| | - Paul B Robertson
- Laboratory for Animate Technologies, Auckland Bioengineering Institute, University of Auckland, Auckland, 1142, New Zealand
| | - Melony J Black
- Department of Anatomy and the Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, 9054, New Zealand
| | - Peter Redgrave
- Department of Psychology, University of Sheffield, Sheffield, S1 1HD, UK
| | - Mark A Sagar
- Laboratory for Animate Technologies, Auckland Bioengineering Institute, University of Auckland, Auckland, 1142, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology and the Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, 9054, New Zealand
| | - John N J Reynolds
- Department of Anatomy and the Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, 9054, New Zealand.
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Abstract
Activity-dependent synaptic plasticity phenomena such as long-term potentiation and long-term depression are candidate mechanisms for storing information in the brain. Regulation of synaptic plasticity is critical for healthy cognition and learning and this is provided in part by metaplasticity, which can act to maintain synaptic transmission within a dynamic range and potentially prevent excitotoxicity. Metaplasticity mechanisms also allow neurons to integrate plasticity-associated signals over time. Interestingly, astrocytes appear to be critical for certain forms of synaptic plasticity and metaplasticity mechanisms. Synaptic dysfunction is increasingly viewed as an early feature of AD that is correlated with the severity of cognitive decline, and the development of these pathologies is correlated with a rise in reactive astrocytes. This review focuses on the contributions of astrocytes to synaptic plasticity and metaplasticity in normal tissue, and addresses whether astroglial pathology may lead to aberrant engagement of these mechanisms in neurological diseases such as Alzheimer's disease.
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Affiliation(s)
- A Singh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand.
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Mockett BG, Richter M, Abraham WC, Müller UC. Therapeutic Potential of Secreted Amyloid Precursor Protein APPsα. Front Mol Neurosci 2017; 10:30. [PMID: 28223920 PMCID: PMC5293819 DOI: 10.3389/fnmol.2017.00030] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 01/25/2017] [Indexed: 11/26/2022] Open
Abstract
Cleavage of the amyloid precursor protein (APP) by α-secretase generates an extracellularly released fragment termed secreted APP-alpha (APPsα). Not only is this process of interest due to the cleavage of APP within the amyloid-beta sequence, but APPsα itself has many physiological properties that suggest its great potential as a therapeutic target. For example, APPsα is neurotrophic, neuroprotective, neurogenic, a stimulator of protein synthesis and gene expression, and enhances long-term potentiation (LTP) and memory. While most early studies have been conducted in vitro, effectiveness in animal models is now being confirmed. These studies have revealed that either upregulating α-secretase activity, acutely administering APPsα or chronic delivery of APPsα via a gene therapy approach can effectively treat mouse models of Alzheimer’s disease (AD) and other disorders such as traumatic head injury. Together these findings suggest the need for intensifying research efforts to harness the therapeutic potential of this multifunctional protein.
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Affiliation(s)
- Bruce G Mockett
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago Otago, New Zealand
| | - Max Richter
- Department of Functional Genomics, Institute for Pharmacy and Molecular Biotechnology, Heidelberg University Heidelberg, Germany
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago Otago, New Zealand
| | - Ulrike C Müller
- Department of Functional Genomics, Institute for Pharmacy and Molecular Biotechnology, Heidelberg University Heidelberg, Germany
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Xiong M, Jones OD, Peppercorn K, Ohline SM, Tate WP, Abraham WC. Secreted amyloid precursor protein-alpha can restore novel object location memory and hippocampal LTP in aged rats. Neurobiol Learn Mem 2017; 138:291-299. [DOI: 10.1016/j.nlm.2016.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/27/2016] [Accepted: 08/08/2016] [Indexed: 12/12/2022]
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Ryan B, Logan BJ, Abraham WC, Williams JM. MicroRNAs, miR-23a-3p and miR-151-3p, Are Regulated in Dentate Gyrus Neuropil following Induction of Long-Term Potentiation In Vivo. PLoS One 2017; 12:e0170407. [PMID: 28125614 PMCID: PMC5268419 DOI: 10.1371/journal.pone.0170407] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/04/2017] [Indexed: 01/04/2023] Open
Abstract
Translation of synaptic mRNA contributes to alterations in the proteome necessary to consolidate long-term potentiation (LTP), a model of memory processes. Yet, how this process is controlled is not fully resolved. MicroRNAs are non-coding RNAs that negatively regulate gene expression by suppressing translation or promoting mRNA degradation. As specific microRNAs are synaptically located, we hypothesized that they are ideally suited to couple synaptic activation, translational regulation, and LTP persistence. The aim of this study was to identify LTP-regulated microRNAs at or near synapses. Accordingly, LTP was induced unilaterally at perforant path-dentate gyrus synapses in awake adult Sprague-Dawley rats. Five hours later, dentate gyrus middle molecular layer neuropil, containing potentiated synapses, was laser-microdissected. MicroRNA expression profiling, using TaqMan Low Density MicroRNA Microarrays (n = 4), identified eight regulated microRNAs. Subsequent individual TaqMan assays confirmed upregulation of miR-23a-3p (1.30 ± 0.10; p = 0.015) and miR-151-3p (1.17 ± 0.19; p = 0.045) in a second cohort (n = 7). Interestingly, bioinformatic analysis indicated that miR-151-3p and miR-23a-3p regulate synaptic reorganisation and transcription, respectively. In summary, we have demonstrated for the first time that microRNAs are regulated in isolated neuropil following LTP induction in vivo, supporting the hypothesis that synaptic, LTP-responsive microRNAs contribute to LTP persistence via regulation of the synaptic proteome.
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Affiliation(s)
- Brigid Ryan
- Department of Anatomy, University of Otago, Dunedin, New Zealand
- The Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
| | - Barbara J. Logan
- The Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Wickliffe C. Abraham
- The Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Joanna M. Williams
- Department of Anatomy, University of Otago, Dunedin, New Zealand
- The Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Rangahau Roro Aotearoa, University of Otago, Dunedin, New Zealand
- * E-mail:
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