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Howes OD, Cummings C, Chapman GE, Shatalina E. Neuroimaging in schizophrenia: an overview of findings and their implications for synaptic changes. Neuropsychopharmacology 2023; 48:151-167. [PMID: 36056106 PMCID: PMC9700830 DOI: 10.1038/s41386-022-01426-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022]
Abstract
Over the last five decades, a large body of evidence has accrued for structural and metabolic brain alterations in schizophrenia. Here we provide an overview of these findings, focusing on measures that have traditionally been thought to reflect synaptic spine density or synaptic activity and that are relevant for understanding if there is lower synaptic density in the disorder. We conducted literature searches to identify meta-analyses or other relevant studies in patients with chronic or first-episode schizophrenia, or in people at high genetic or clinical risk for psychosis. We identified 18 meta-analyses including over 50,000 subjects in total, covering: structural MRI measures of gyrification index, grey matter volume, grey matter density and cortical thickness, neurite orientation dispersion and density imaging, PET imaging of regional glucose metabolism and magnetic resonance spectroscopy measures of N-acetylaspartate. We also review preclinical evidence on the relationship between ex vivo synaptic measures and structural MRI imaging, and PET imaging of synaptic protein 2A (SV2A). These studies show that schizophrenia is associated with lower grey matter volumes and cortical thickness, accelerated grey matter loss over time, abnormal gyrification patterns, and lower regional SV2A levels and metabolic markers in comparison to controls (effect sizes from ~ -0.11 to -1.0). Key regions affected include frontal, anterior cingulate and temporal cortices and the hippocampi. We identify several limitations for the interpretation of these findings in terms of understanding synaptic alterations. Nevertheless, taken with post-mortem findings, they suggest that schizophrenia is associated with lower synaptic density in some brain regions. However, there are several gaps in evidence, in particular whether SV2A findings generalise to other cohorts.
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Affiliation(s)
- Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK.
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
- South London and Maudsley NHS Foundation Trust, London, UK.
| | - Connor Cummings
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Clare Hall (College), University of Cambridge, Cambridge, UK
| | - George E Chapman
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- South London and Maudsley NHS Foundation Trust, London, UK
| | - Ekaterina Shatalina
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
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2
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Wang G, Liu L. Amblyopia: progress and promise of functional magnetic resonance imaging. Graefes Arch Clin Exp Ophthalmol 2022; 261:1229-1246. [PMID: 36282454 DOI: 10.1007/s00417-022-05826-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 08/14/2022] [Accepted: 09/02/2022] [Indexed: 11/28/2022] Open
Abstract
Amblyopia is a neurodevelopmental disorder characterized by functional deficits in the visual cortex. Functional magnetic resonance imaging (fMRI) is the most commonly used neuroimaging technique for investigating amblyopia. Herein, we systematically searched a PubMed database from inception to December 2021 to highlight the current progress and promises about fMRI technology in amblyopia; amblyopia's neural mechanism, the comparison of different types of amblyopia, and the evaluation of the therapeutic effect were explored. Relevant articles published in English and appropriate cross-references were considered for inclusion, including basic studies, imaging techniques, clinical diagnostic and therapeutic studies, case series, and reviews.
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Affiliation(s)
- Guiqu Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Longqian Liu
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, China.
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, 610041, China.
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3
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Howes OD, Shatalina E. Integrating the Neurodevelopmental and Dopamine Hypotheses of Schizophrenia and the Role of Cortical Excitation-Inhibition Balance. Biol Psychiatry 2022; 92:501-513. [PMID: 36008036 DOI: 10.1016/j.biopsych.2022.06.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/16/2022] [Accepted: 06/04/2022] [Indexed: 12/23/2022]
Abstract
The neurodevelopmental and dopamine hypotheses are leading theories of the pathoetiology of schizophrenia, but they were developed in isolation. However, since they were originally proposed, there have been considerable advances in our understanding of the normal neurodevelopmental refinement of synapses and cortical excitation-inhibition (E/I) balance, as well as preclinical findings on the interrelationship between cortical and subcortical systems and new in vivo imaging and induced pluripotent stem cell evidence for lower synaptic density markers in patients with schizophrenia. Genetic advances show that schizophrenia is associated with variants linked to genes affecting GABA (gamma-aminobutyric acid) and glutamatergic signaling as well as neurodevelopmental processes. Moreover, in vivo studies on the effects of stress, particularly during later development, show that it leads to synaptic elimination. We review these lines of evidence as well as in vivo evidence for altered cortical E/I balance and dopaminergic dysfunction in schizophrenia. We discuss mechanisms through which frontal cortex circuitry may regulate striatal dopamine and consider how frontal E/I imbalance may cause dopaminergic dysregulation to result in psychotic symptoms. This integrated neurodevelopmental and dopamine hypothesis suggests that overpruning of synapses, potentially including glutamatergic inputs onto frontal cortical interneurons, disrupts the E/I balance and thus underlies cognitive and negative symptoms. It could also lead to disinhibition of excitatory projections from the frontal cortex and possibly other regions that regulate mesostriatal dopamine neurons, resulting in dopamine dysregulation and psychotic symptoms. Together, this explains a number of aspects of the epidemiology and clinical presentation of schizophrenia and identifies new targets for treatment and prevention.
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Affiliation(s)
- Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, United Kingdom; Department of Psychosis, Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
| | - Ekaterina Shatalina
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, United Kingdom
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4
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Balsor JL, Arbabi K, Singh D, Kwan R, Zaslavsky J, Jeyanesan E, Murphy KM. Corrigendum: A Practical Guide to Sparse k-Means Clustering for Studying Molecular Development of the Human Brain. Front Neurosci 2022; 16:907479. [PMID: 35516804 PMCID: PMC9063405 DOI: 10.3389/fnins.2022.907479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Justin L. Balsor
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada
| | - Keon Arbabi
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada
| | - Desmond Singh
- Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
| | - Rachel Kwan
- Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
| | - Jonathan Zaslavsky
- Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
| | - Ewalina Jeyanesan
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada
| | - Kathryn M. Murphy
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada
- Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
- *Correspondence: Kathryn M. Murphy
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5
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Balsor JL, Arbabi K, Singh D, Kwan R, Zaslavsky J, Jeyanesan E, Murphy KM. A Practical Guide to Sparse k-Means Clustering for Studying Molecular Development of the Human Brain. Front Neurosci 2021; 15:668293. [PMID: 34867140 PMCID: PMC8636820 DOI: 10.3389/fnins.2021.668293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 09/30/2021] [Indexed: 12/29/2022] Open
Abstract
Studying the molecular development of the human brain presents unique challenges for selecting a data analysis approach. The rare and valuable nature of human postmortem brain tissue, especially for developmental studies, means the sample sizes are small (n), but the use of high throughput genomic and proteomic methods measure the expression levels for hundreds or thousands of variables [e.g., genes or proteins (p)] for each sample. This leads to a data structure that is high dimensional (p ≫ n) and introduces the curse of dimensionality, which poses a challenge for traditional statistical approaches. In contrast, high dimensional analyses, especially cluster analyses developed for sparse data, have worked well for analyzing genomic datasets where p ≫ n. Here we explore applying a lasso-based clustering method developed for high dimensional genomic data with small sample sizes. Using protein and gene data from the developing human visual cortex, we compared clustering methods. We identified an application of sparse k-means clustering [robust sparse k-means clustering (RSKC)] that partitioned samples into age-related clusters that reflect lifespan stages from birth to aging. RSKC adaptively selects a subset of the genes or proteins contributing to partitioning samples into age-related clusters that progress across the lifespan. This approach addresses a problem in current studies that could not identify multiple postnatal clusters. Moreover, clusters encompassed a range of ages like a series of overlapping waves illustrating that chronological- and brain-age have a complex relationship. In addition, a recently developed workflow to create plasticity phenotypes (Balsor et al., 2020) was applied to the clusters and revealed neurobiologically relevant features that identified how the human visual cortex changes across the lifespan. These methods can help address the growing demand for multimodal integration, from molecular machinery to brain imaging signals, to understand the human brain’s development.
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Affiliation(s)
- Justin L Balsor
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada
| | - Keon Arbabi
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada
| | - Desmond Singh
- Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
| | - Rachel Kwan
- Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
| | - Jonathan Zaslavsky
- Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
| | - Ewalina Jeyanesan
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada
| | - Kathryn M Murphy
- McMaster Neuroscience Graduate Program, McMaster University, Hamilton, ON, Canada.,Department of Psychology, Neuroscience and Behavior, McMaster University, Hamilton, ON, Canada
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Karoglu-Eravsar ET, Tuz-Sasik MU, Adams MM. Short-term dietary restriction maintains synaptic plasticity whereas short-term overfeeding alters cellular dynamics in the aged brain: evidence from the zebrafish model organism. Neurobiol Aging 2021; 106:169-182. [PMID: 34284260 DOI: 10.1016/j.neurobiolaging.2021.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 05/06/2021] [Accepted: 06/12/2021] [Indexed: 12/12/2022]
Abstract
Increased caloric intake (OF) impairs quality of life causing comorbidities with other diseases and cognitive deficits, whereas dietary restriction (DR) increases healthspan by preventing age-related deteriorations. To understand the effects of these opposing dietary regimens on the cellular and synaptic dynamics during brain aging, the zebrafish model, which shows gradual aging like mammals, was utilized. Global changes in cellular and synaptic markers with respect to age and a 12 week dietary regimen of OF and DR demonstrated that aging reduces the levels of the glutamate receptor subunits, GLUR2/3, inhibitory synaptic clustering protein, GEP, synaptic vesicle protein, SYP, and early-differentiated neuronal marker, HuC. DR significantly elevates levels of glutamate receptor subunits, GLUR2/3, and NMDA clustering protein, PSD95, levels, while OF subtly increases the level of the neuronal protein, DCAMKL1. These data suggest that decreased caloric intake within the context of aging has more robust effects on synapses than cellular proteins, whereas OF alters cellular dynamics. Thus, patterns like these should be taken into account for possible translation to human subjects.
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Affiliation(s)
- Elif Tugce Karoglu-Eravsar
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey; Department of Psychology, Selcuk University, Konya, Turkey
| | - Melek Umay Tuz-Sasik
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
| | - Michelle M Adams
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey; Department of Psychology, Bilkent University, Ankara, Turkey.
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7
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Karoglu-Eravsar ET, Tuz-Sasik MU, Adams MM. Environmental enrichment applied with sensory components prevents age-related decline in synaptic dynamics: Evidence from the zebrafish model organism. Exp Gerontol 2021; 149:111346. [PMID: 33838219 DOI: 10.1016/j.exger.2021.111346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/31/2021] [Accepted: 04/03/2021] [Indexed: 10/21/2022]
Abstract
Progression of cognitive decline with or without neurodegeneration varies among elderly subjects. The main aim of the current study was to illuminate the molecular mechanisms that promote and retain successful aging in the context of factors such as environment and gender, both of which alter the resilience of the aging brain. Environmental enrichment (EE) is one intervention that may lead to the maintenance of cognitive processing at older ages in both humans and animal subjects. EE is easily applied to different model organisms, including zebrafish, which show similar age-related molecular and behavioral changes as humans. Global changes in cellular and synaptic markers with respect to age, gender and 4-weeks of EE applied with sensory stimulation were investigated using the zebrafish model organism. Results indicated that EE increases brain weight in an age-dependent manner without affecting general body parameters like body mass index (BMI). Age-related declines in the presynaptic protein synaptophysin, AMPA-type glutamate receptor subunits and a post-mitotic neuronal marker were observed and short-term EE prevents these changes in aged animals, as well as elevates levels of the inhibitory scaffolding protein, gephyrin. Gender-driven alterations were observed in the levels of the glutamate receptor subunits. Oxidative stress markers were significantly increased in the old animals, while exposure to EE did not alter this pattern. These data suggest that EE with sensory stimulation exerts its effects mainly on age-related changes in synaptic dynamics, which likely increase brain resilience through specific cellular mechanisms.
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Affiliation(s)
- Elif Tugce Karoglu-Eravsar
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey; Department of Psychology, Selcuk University, Konya, Turkey
| | - Melek Umay Tuz-Sasik
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
| | - Michelle M Adams
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey; Department of Psychology, Bilkent University, Ankara, Turkey.
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8
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Xiang Y, Chen J, Xu F, Lin Z, Xiao J, Lin Z, Lin H. Longtime Vision Function Prediction in Childhood Cataract Patients Based on Optical Coherence Tomography Images. Front Bioeng Biotechnol 2021; 9:646479. [PMID: 33748090 PMCID: PMC7973224 DOI: 10.3389/fbioe.2021.646479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 02/08/2021] [Indexed: 11/21/2022] Open
Abstract
The results of visual prediction reflect the tendency and speed of visual development during a future period, based on which ophthalmologists and guardians can know the potential visual prognosis in advance, decide on an intervention plan, and contribute to visual development. In our study, we developed an intelligent system based on the features of optical coherence tomography images for long-term prediction of best corrected visual acuity (BCVA) 3 and 5 years in advance. Two hundred eyes of 132 patients were included. Six machine learning algorithms were applied. In the BCVA predictions, small errors within two lines of the visual chart were achieved. The mean absolute errors (MAEs) between the prediction results and ground truth were 0.1482–0.2117 logMAR for 3-year predictions and 0.1198–0.1845 logMAR for 5-year predictions; the root mean square errors (RMSEs) were 0.1916–0.2942 logMAR for 3-year predictions and 0.1692–0.2537 logMAR for 5-year predictions. This is the first study to predict post-therapeutic BCVAs in young children. This work establishes a reliable method to predict prognosis 5 years in advance. The application of our research contributes to the design of visual intervention plans and visual prognosis.
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Affiliation(s)
- Yifan Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jingjing Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Fabao Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhuoling Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jun Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhenzhe Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Haotian Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.,Center of Precision Medicine, Sun Yat-sen University, Guangzhou, China
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Bhat A, Tan V, Heng B, Lovejoy DB, Sakharkar MK, Essa MM, Chidambaram SB, Guillemin GJ. Roflumilast, a cAMP-Specific Phosphodiesterase-4 Inhibitor, Reduces Oxidative Stress and Improves Synapse Functions in Human Cortical Neurons Exposed to the Excitotoxin Quinolinic Acid. ACS Chem Neurosci 2020; 11:4405-4415. [PMID: 33261317 DOI: 10.1021/acschemneuro.0c00636] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The overexpression of phosphodiesterase 4 (PDE4) enzymes is reported in several neurodegenerative diseases. PDE4 depletes cyclic 3'-5' adenosine monophosphate (cAMP) and, in turn, cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF), the key players in cognitive function. The present study was undertaken to investigate the mechanism behind the protective effects of roflumilast (ROF), a cAMP-specific PDE4 inhibitor, against quinolinic acid (QUIN)-induced neurotoxicity using human primary cortical neurons. Cytotoxicity was analyzed using an MTS assay. Reactive oxygen species (ROS) and mitochondrial membrane potential were measured by DCF-DA and JC-10 staining, respectively. Caspase 3/7 activity was measured using an ApoTox-Glo Triplex assay kit. cAMP was measured using an ELISA kit. The protein expression of CREB, BDNF, SAP-97, synaptophysin, synapsin-I, and PSD-95 was analyzed by the Western blotting technique. QUIN exposure down-regulated CREB, BDNF, and synaptic protein expression in neurons. Pretreatment with ROF increased the intracellular cAMP, mitochondrial membrane potential, and nicotinamide adenine dinucleotide (NAD+) content and decreased the ROS and caspase 3/7 levels in QUIN-exposed neurons. ROF up-regulated the expression of synapse proteins SAP-97, synaptophysin, synapsin-I, PSD-95, and CREB and BDNF, which indicates its potential role in memory. This study suggests for the first time that QUIN causes pre- and postsynaptic protein damage. We further demonstrate the restorative effects of ROF on the mitochondrial membrane potential and antiapoptotic properties in human neurons. These data encourage further investigations to reposition ROF in neurodegenerative diseases and their associated cognitive deficits.
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Affiliation(s)
- Abid Bhat
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Sri Shivarathreeshwara Nagar, Mysuru, Karnataka 570015, India
- Neuroinflammation Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Vanessa Tan
- Neuroinflammation Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Benjamin Heng
- Neuroinflammation Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - David B. Lovejoy
- Neuroinflammation Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Meena Kishore Sakharkar
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A2, Canada
| | - Musthafa Mohamed Essa
- Department of Food Science and Nutrition, CAMS, Sultan Qaboos University, Muscat, Oman
- Ageing and Dementia Research Group, Sultan Qaboos University, Muscat, Oman
| | - Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Sri Shivarathreeshwara Nagar, Mysuru, Karnataka 570015, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, Mysuru, Karnataka 570015, India
| | - Gilles J. Guillemin
- Neuroinflammation Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
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Balsor JL, Ahuja D, Jones DG, Murphy KM. A Primer on Constructing Plasticity Phenotypes to Classify Experience-Dependent Development of the Visual Cortex. Front Cell Neurosci 2020; 14:245. [PMID: 33192303 PMCID: PMC7482673 DOI: 10.3389/fncel.2020.00245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 07/15/2020] [Indexed: 11/20/2022] Open
Abstract
Many neural mechanisms regulate experience-dependent plasticity in the visual cortex (V1), and new techniques for quantifying large numbers of proteins or genes are transforming how plasticity is studied into the era of big data. With those large data sets comes the challenge of extracting biologically meaningful results about visual plasticity from data-driven analytical methods designed for high-dimensional data. In other areas of neuroscience, high-information content methodologies are revealing more subtle aspects of neural development and individual variations that give rise to a richer picture of brain disorders. We have developed an approach for studying V1 plasticity that takes advantage of the known functions of many synaptic proteins for regulating visual plasticity. We use that knowledge to rebrand protein measurements into plasticity features and combine those into a plasticity phenotype. Here, we provide a primer for analyzing experience-dependent plasticity in V1 using example R code to identify high-dimensional changes in a group of proteins. We describe using PCA to classify high-dimensional plasticity features and use them to construct a plasticity phenotype. In the examples, we show how to use this analytical framework to study and compare experience-dependent development and plasticity of V1 and apply the plasticity phenotype to translational research questions. We include an R package “PlasticityPhenotypes” that aggregates the coding packages and custom code written in RStudio to construct and analyze plasticity phenotypes.
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Affiliation(s)
- Justin L Balsor
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, ON, Canada
| | - Dezi Ahuja
- Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, ON, Canada
| | | | - Kathryn M Murphy
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, ON, Canada.,Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, ON, Canada
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11
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Evaluation of cochlear activity in normal-hearing musicians. Hear Res 2020; 395:108027. [PMID: 32659614 DOI: 10.1016/j.heares.2020.108027] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/07/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The present study compared wave I amplitude of auditory brainstem responses (ABRs), a potential indicator of cochlear synaptopathy, among musicians and non-musicians with normal audiograms. DESIGN Noise exposure background (NEB) was evaluated using an online questionnaire. Two-channel ABRs were recorded from the left ear using click stimuli. One channel utilized an ipsilateral tiptrode, and another channel utilized an ipsilateral mastoid electrode. ABRs were collected at 90, 75, and 60 dBnHL. A mixed model was used to analyze the effect of group, electrodes, and stimulus levels on ABR wave I amplitude. STUDY SAMPLE 75 collegiate students with normal hearing participated in the study and were grouped into a non-music major group (n = 25), a brass major group (n = 25), and a voice major group (n = 25). RESULTS The NEB was negatively associated with the action potential (AP) and ABR wave I amplitude for click intensity levels at 75 dBnHL. The mean amplitude of the ABR wave I was not significantly different between the three groups. CONCLUSION The weak negative association of AP and ABR wave I amplitude with NEB cannot be solely attributed to evidence of cochlear synaptopathy in humans as the possibility of hair cell damage cannot be ruled out. Future research should investigate the effects of reduced cochlear output on the supra-threshold speech processing abilities of student musicians.
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12
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Xie J, Jusuf PR, Bui BV, Goodbourn PT. Experience-dependent development of visual sensitivity in larval zebrafish. Sci Rep 2019; 9:18931. [PMID: 31831839 PMCID: PMC6908733 DOI: 10.1038/s41598-019-54958-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 11/19/2019] [Indexed: 12/25/2022] Open
Abstract
The zebrafish (Danio rerio) is a popular vertebrate model for studying visual development, especially at the larval stage. For many vertebrates, post-natal visual experience is essential to fine-tune visual development, but it is unknown how experience shapes larval zebrafish vision. Zebrafish swim with a moving texture; in the wild, this innate optomotor response (OMR) stabilises larvae in moving water, but it can be exploited in the laboratory to assess zebrafish visual function. Here, we compared spatial-frequency tuning inferred from OMR between visually naïve and experienced larvae from 5 to 7 days post-fertilisation. We also examined development of synaptic connections between neurons by quantifying post-synaptic density 95 (PSD-95) in larval retinae. PSD-95 is closely associated with N-methyl-D-aspartate (NMDA) receptors, the neurotransmitter-receptor proteins underlying experience-dependent visual development. We found that rather than following an experience-independent genetic programme, developmental changes in visual spatial-frequency tuning at the larval stage required visual experience. Exposure to motion evoking OMR yielded no greater improvement than exposure to static form, suggesting that increased sensitivity as indexed by OMR was driven not by motor practice but by visual experience itself. PSD-95 density varied with visual sensitivity, suggesting that experience may have up-regulated clustering of PSD-95 for synaptic maturation in visual development.
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Affiliation(s)
- Jiaheng Xie
- School of Biosciences, The University of Melbourne, Melbourne, Australia
| | - Patricia R Jusuf
- School of Biosciences, The University of Melbourne, Melbourne, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Patrick T Goodbourn
- Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Australia.
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13
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Classification of Visual Cortex Plasticity Phenotypes following Treatment for Amblyopia. Neural Plast 2019; 2019:2564018. [PMID: 31565045 PMCID: PMC6746165 DOI: 10.1155/2019/2564018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 04/04/2019] [Accepted: 05/13/2019] [Indexed: 12/25/2022] Open
Abstract
Monocular deprivation (MD) during the critical period (CP) has enduring effects on visual acuity and the functioning of the visual cortex (V1). This experience-dependent plasticity has become a model for studying the mechanisms, especially glutamatergic and GABAergic receptors, that regulate amblyopia. Less is known, however, about treatment-induced changes to those receptors and if those changes differentiate treatments that support the recovery of acuity versus persistent acuity deficits. Here, we use an animal model to explore the effects of 3 visual treatments started during the CP (n = 24, 10 male and 14 female): binocular vision (BV) that promotes good acuity versus reverse occlusion (RO) and binocular deprivation (BD) that causes persistent acuity deficits. We measured the recovery of a collection of glutamatergic and GABAergic receptor subunits in the V1 and modeled recovery of kinetics for NMDAR and GABAAR. There was a complex pattern of protein changes that prompted us to develop an unbiased data-driven approach for these high-dimensional data analyses to identify plasticity features and construct plasticity phenotypes. Cluster analysis of the plasticity phenotypes suggests that BV supports adaptive plasticity while RO and BD promote a maladaptive pattern. The RO plasticity phenotype appeared more similar to adults with a high expression of GluA2, and the BD phenotypes were dominated by GABAA α1, highlighting that multiple plasticity phenotypes can underlie persistent poor acuity. After 2-4 days of BV, the plasticity phenotypes resembled normals, but only one feature, the GluN2A:GluA2 balance, returned to normal levels. Perhaps, balancing Hebbian (GluN2A) and homeostatic (GluA2) mechanisms is necessary for the recovery of vision.
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14
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Bhatt IS, Wang J. Evaluation of dichotic listening performance in normal-hearing, noise-exposed young females. Hear Res 2019; 380:10-21. [PMID: 31167151 DOI: 10.1016/j.heares.2019.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 05/07/2019] [Accepted: 05/26/2019] [Indexed: 10/26/2022]
Abstract
Recent animal studies have shown that intense noise exposures that produce robust temporary threshold shift (TTS) can inflict irreversible damage to the synaptic connections between the inner hair cells and auditory neurons. It was hypothesized that noise-induced cochlear synaptopathy may cause impaired acoustic encoding in the central auditory nervous system leading to impaired speech perception, particularly in challenging listening situations. The aim of the study was to evaluate the influence of high noise exposure background (NEB) on dichotic listening performance, speech-in-noise performance, and auditory brainstem responses (ABR) measured in young females with normal audiograms. The central hypothesis was that individuals with high NEB would exhibit reduced ABR wave I amplitude and subsequently would exhibit poorer performance on speech-in-noise and dichotic listening. In a sample of 32 females (14 with high NEB and 18 with low NEB) aged 18-35 years, the study compared behavioral hearing thresholds (from 250 to 16000 Hz), distortion-product otoacoustic emissions (DPOAEs, 1000-16000 Hz), click-evoked ABR, QuickSIN signal-to-noise ratio (SNR) loss and dichotic digit test (DDT). The results showed no clear association between NEB, and hearing thresholds, DPOAEs, click-evoked ABR measures, and QuickSIN SNR loss. Individuals with high NEB revealed significantly lower DDT scores and evidence of reduced right ear advantage compared to individuals with low NEB. The poorer performance in DDT and the ear asymmetry in DDT scores with normal ABR findings suggest that high NEB might alter the hemispheric organization of speech-sound processing and cognitive control. The clinical significance of the present findings is discussed.
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Affiliation(s)
- Ishan Sunilkumar Bhatt
- Department of Communication Sciences & Disorders, Northern Arizona University, Flagstaff, AZ, 86011, USA.
| | - Jin Wang
- Department of Mathematics & Statistics, Northern Arizona University, Flagstaff, AZ, 86011, USA
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15
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Brewer CL, Baccei ML. The development of pain circuits and unique effects of neonatal injury. J Neural Transm (Vienna) 2019; 127:467-479. [PMID: 31399790 DOI: 10.1007/s00702-019-02059-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/03/2019] [Indexed: 12/15/2022]
Abstract
Pain is a necessary sensation that prevents further tissue damage, but can be debilitating and detrimental in daily life under chronic conditions. Neuronal activity strongly regulates the maturation of the somatosensory system, and aberrant sensory input caused by injury or inflammation during critical periods of early postnatal development can have prolonged, detrimental effects on pain processing. This review will outline the maturation of neuronal circuits responsible for the transmission of nociceptive signals and the generation of pain sensation-involving peripheral sensory neurons, the spinal cord dorsal horn, and brain-in addition to the influences of the neuroimmune system on somatosensation. This summary will also highlight the unique effects of neonatal tissue injury on the maturation of these systems and subsequent consequences for adult somatosensation. Ultimately, this review emphasizes the need to account for age as an independent variable in basic and clinical pain research, and importantly, to consider the distinct qualities of the pediatric population when designing novel strategies for pain management.
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Affiliation(s)
- Chelsie L Brewer
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA
- Department of Anesthesiology, Pain Research Center, University of Cincinnati Medical Center, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA
| | - Mark L Baccei
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA.
- Department of Anesthesiology, Pain Research Center, University of Cincinnati Medical Center, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA.
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16
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Xiang Q, Li XH, Fang XX, Jia J, Ren J, Dong YC, Ou-Yang C. Alterations of synaptic plasticity in aged rats: Evidence of functional and morphological studies. Technol Health Care 2018; 26:271-278. [PMID: 29309043 DOI: 10.3233/thc-170978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The aging-related disease and associated neurodegenerative complications, such as cognitive impairment, has received increasing attention. OBJECTIVE The aim of this study was to show changes in cognitive behavior and molecular related the synaptic plasticity in aged-induced cognitive deficits rats. METHODS We used novel object recognition testing and morphological staining as well as western blot to detect changes in cognitive behavior and molecular related the synaptic plasticity. RESULTS The morphological changes of synaptic structure and number on hippocampal neurons and learning and memory deficits were shown during natural aging. Moreover, learning and memory improvement was associated with alterations of hippocampal synaptic plasticity-related proteins, such as SNAP-25, synaptophysin, snapsoin-1 and so on, which distributes to cognitive decline in natural aging. CONCLUSIONS Our study provides more behavior and molecular evidence on relationship of cognitive deficits and aging.
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17
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Abstract
The primary visual cortex (V1) is the first cortical area that processes visual information. Normal development of V1 depends on binocular vision during the critical period, and age-related losses of vision are linked with neurobiological changes in V1. Animal studies have provided important details about the neurobiological mechanisms in V1 that support normal vision or are changed by visual diseases. There is very little information, however, about those neurobiological mechanisms in human V1. That lack of information has hampered the translation of biologically inspired treatments from preclinical models to effective clinical treatments. We have studied human V1 to characterize the expression of neurobiological mechanisms that regulate visual perception and neuroplasticity. We have identified five stages of development for human V1 that start in infancy and continue across the life span. Here, we describe these stages, compare them with visual and anatomical milestones, and discuss implications for translating treatments for visual disorders that depend on neuroplasticity of V1 function.
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Affiliation(s)
- Caitlin R Siu
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, ON, Canada
| | - Kathryn M Murphy
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, ON, Canada.,Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, Canada
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18
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Ohmura Y, Kuniyoshi Y. A translational model to determine rodent's age from human foetal age. Sci Rep 2017; 7:17248. [PMID: 29222462 PMCID: PMC5722919 DOI: 10.1038/s41598-017-17571-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/16/2017] [Indexed: 01/03/2023] Open
Abstract
To understand the prenatal origin of developmental and psychiatric disorders, studies in laboratory animals are imperative. However, the developmental pace differs between humans and animals; hence, corresponding human ages must be estimated to infer the most vulnerable developmental timings in humans. Because rats and mice are extensively used as models in developmental research, a correspondence between human foetal ages and rodents’ ages must be precisely determined; thus, developing a translational model is of utmost importance. Optimizing a translational model involves classifying the brain regions according to developmental paces, but previous studies have conducted this classification arbitrarily. Here we used a clustering method and showed that the brain regions can be classified into two groups. To quantify the developmental pace, we gathered data for a range of development events in humans and rodents and created a linear mixed model that translates human developmental timings into the corresponding rat timings. We conducted an automatic classification of brain regions using an EM algorithm and obtained a model to translate human foetal age to rat age. Our model could predict rat developmental timings within 2.5 days of root mean squared error. This result provides useful information for designing animal studies and clinical tests.
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Affiliation(s)
- Yoshiyuki Ohmura
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan.
| | - Yasuo Kuniyoshi
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
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19
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Skene NG, Roy M, Grant SG. A genomic lifespan program that reorganises the young adult brain is targeted in schizophrenia. eLife 2017; 6. [PMID: 28893375 PMCID: PMC5595438 DOI: 10.7554/elife.17915] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 08/15/2017] [Indexed: 12/19/2022] Open
Abstract
The genetic mechanisms regulating the brain and behaviour across the lifespan are poorly understood. We found that lifespan transcriptome trajectories describe a calendar of gene regulatory events in the brain of humans and mice. Transcriptome trajectories defined a sequence of gene expression changes in neuronal, glial and endothelial cell-types, which enabled prediction of age from tissue samples. A major lifespan landmark was the peak change in trajectories occurring in humans at 26 years and in mice at 5 months of age. This species-conserved peak was delayed in females and marked a reorganization of expression of synaptic and schizophrenia-susceptibility genes. The lifespan calendar predicted the characteristic age of onset in young adults and sex differences in schizophrenia. We propose a genomic program generates a lifespan calendar of gene regulation that times age-dependent molecular organization of the brain and mutations that interrupt the program in young adults cause schizophrenia. In our lifetime, we go through many changes – physically and also intellectually. At certain ages, we are particularly vulnerable to develop psychiatric disorders, and the majority of mental conditions start to manifest in teenagers and young adults. The symptoms for schizophrenia, for example, a mental health disorder in which patients often experience hallucinations, delusion or changes in behavior, typically start in the mid-twenties. Schizophrenia tends to run in families and it is likely that different combinations of faulty genes that affect the connections between nerve cells increase the chance of having the disease. Until now, scientists have assumed that certain situations and environmental factors trigger the condition, but it was unknown if genes could influence the age at which the disease will begin. To explore whether genes in the brain change at certain time points, Skene et al. examined how the genes are turned on and off across the lifespan of healthy mice and humans. The results showed that in both mice and humans, a ‘genetic lifespan calendar’ controlled every cell type in the brain and directed the way they worked at different ages. The timing was so precise that it was possible tell the age of a mouse or a person simply by looking at the way the genes were expressed in a tissue sample. Skene et al. then studied how the genetic lifespan calendar controlled the genes damaged in schizophrenia, and found that the calendar caused a major reorganization of the genes at the time when the symptoms started. This suggests that the genetic lifespan calendar is a crucial factor that can determine at what age the disease will start. The next step will be to study how the genetic lifespan calendar programs changes throughout the brain and to explore if it could be manipulated to change how the brain ages. This could help to develop new types of treatments for schizophrenia and other conditions of the brain.
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Affiliation(s)
- Nathan G Skene
- Genes to Cognition Programme, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Marcia Roy
- Genes to Cognition Programme, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Seth Gn Grant
- Genes to Cognition Programme, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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20
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The effects of noise exposure and musical training on suprathreshold auditory processing and speech perception in noise. Hear Res 2017; 353:224-236. [DOI: 10.1016/j.heares.2017.07.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/25/2017] [Accepted: 07/13/2017] [Indexed: 12/13/2022]
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21
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Karoglu ET, Halim DO, Erkaya B, Altaytas F, Arslan-Ergul A, Konu O, Adams MM. Aging alters the molecular dynamics of synapses in a sexually dimorphic pattern in zebrafish ( Danio rerio ). Neurobiol Aging 2017; 54:10-21. [DOI: 10.1016/j.neurobiolaging.2017.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 02/09/2017] [Accepted: 02/10/2017] [Indexed: 10/20/2022]
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22
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Development of Glutamatergic Proteins in Human Visual Cortex across the Lifespan. J Neurosci 2017; 37:6031-6042. [PMID: 28554889 DOI: 10.1523/jneurosci.2304-16.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 04/30/2017] [Accepted: 05/03/2017] [Indexed: 11/21/2022] Open
Abstract
Traditionally, human primary visual cortex (V1) has been thought to mature within the first few years of life, based on anatomical studies of synapse formation, and establishment of intracortical and intercortical connections. Human vision, however, develops well beyond the first few years. Previously, we found prolonged development of some GABAergic proteins in human V1 (Pinto et al., 2010). Yet as >80% of synapses in V1 are excitatory, it remains unanswered whether the majority of synapses regulating experience-dependent plasticity and receptive field properties develop late, like their inhibitory counterparts. To address this question, we used Western blotting of postmortem tissue from human V1 (12 female, 18 male) covering a range of ages. Then we quantified a set of postsynaptic glutamatergic proteins (PSD-95, GluA2, GluN1, GluN2A, GluN2B), calculated indices for functional pairs that are developmentally regulated (GluA2:GluN1; GluN2A:GluN2B), and determined interindividual variability. We found early loss of GluN1, prolonged development of PSD-95 and GluA2 into late childhood, protracted development of GluN2A until ∼40 years, and dramatic loss of GluN2A in aging. The GluA2:GluN1 index switched at ∼1 year, but the GluN2A:GluN2B index continued to shift until ∼40 year before changing back to GluN2B in aging. We also identified young childhood as a stage of heightened interindividual variability. The changes show that human V1 develops gradually through a series of five orchestrated stages, making it likely that V1 participates in visual development and plasticity across the lifespan.SIGNIFICANCE STATEMENT Anatomical structure of human V1 appears to mature early, but vision changes across the lifespan. This discrepancy has fostered two hypotheses: either other aspects of V1 continue changing, or later changes in visual perception depend on extrastriate areas. Previously, we showed that some GABAergic synaptic proteins change across the lifespan, but most synapses in V1 are excitatory leaving unanswered how they change. So we studied expression of glutamatergic proteins in human V1 to determine their development. Here we report prolonged maturation of glutamatergic proteins, with five stages that map onto life-long changes in human visual perception. Thus, the apparent discrepancy between development of structure and function may be explained by life-long synaptic changes in human V1.
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23
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Chang P, Fabrizi L, Olhede S, Fitzgerald M. The Development of Nociceptive Network Activity in the Somatosensory Cortex of Freely Moving Rat Pups. Cereb Cortex 2016; 26:4513-4523. [PMID: 27797835 PMCID: PMC5193146 DOI: 10.1093/cercor/bhw330] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/02/2016] [Indexed: 12/13/2022] Open
Abstract
Cortical perception of noxious stimulation is an essential component of pain experience but it is not known how cortical nociceptive activity emerges during brain development. Here we use continuous telemetric electrocorticogram (ECoG) recording from the primary somatosensory cortex (S1) of awake active rat pups to map functional nociceptive processing in the developing brain over the first 4 weeks of life. Cross-sectional and longitudinal recordings show that baseline S1 ECoG energy increases steadily with age, with a distinctive beta component replaced by a distinctive theta component in week 3. Event-related potentials were evoked by brief noxious hindpaw skin stimulation at all ages tested, confirming the presence of functional nociceptive spinothalamic inputs in S1. However, hindpaw incision, which increases pain sensitivity at all ages, did not increase S1 ECoG energy until week 3. A significant increase in gamma (20–50 Hz) energy occurred in the presence of skin incision at week 3 accompanied by a longer-lasting increase in theta (4–8 Hz) energy at week 4. Continuous ECoG recording demonstrates specific postnatal functional stages in the maturation of S1 cortical nociception. Somatosensory cortical coding of an ongoing pain “state” in awake rat pups becomes apparent between 2 and 4 weeks of age.
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Affiliation(s)
- P Chang
- Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E6BT, UK.,Current address: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London WC1N 3BG, UK
| | - L Fabrizi
- Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E6BT, UK
| | - S Olhede
- Department of Statistical Science, University College London, London WC1E6BT, UK
| | - M Fitzgerald
- Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E6BT, UK
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24
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Scarlett JM, Rojas JM, Matsen ME, Kaiyala KJ, Stefanovski D, Bergman RN, Nguyen HT, Dorfman MD, Lantier L, Wasserman DH, Mirzadeh Z, Unterman TG, Morton GJ, Schwartz MW. Central injection of fibroblast growth factor 1 induces sustained remission of diabetic hyperglycemia in rodents. Nat Med 2016; 22:800-6. [PMID: 27213816 PMCID: PMC4938755 DOI: 10.1038/nm.4101] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/08/2016] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes (T2D) is among the most common and costly disorders worldwide. The goal of current medical management for T2D is to transiently ameliorate hyperglycemia through daily dosing of one or more antidiabetic drugs. Hypoglycemia and weight gain are common side effects of therapy, and sustained disease remission is not obtainable with nonsurgical approaches. On the basis of the potent glucose-lowering response elicited by activation of brain fibroblast growth factor (FGF) receptors, we explored the antidiabetic efficacy of centrally administered FGF1, which, unlike other FGF peptides, activates all FGF receptor subtypes. We report that a single intracerebroventricular injection of FGF1 at a dose one-tenth of that needed for antidiabetic efficacy following peripheral injection induces sustained diabetes remission in both mouse and rat models of T2D. This antidiabetic effect is not secondary to weight loss, does not increase the risk of hypoglycemia, and involves a novel and incompletely understood mechanism for increasing glucose clearance from the bloodstream. We conclude that the brain has an inherent potential to induce diabetes remission and that brain FGF receptors are potential pharmacological targets for achieving this goal.
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MESH Headings
- Adipose Tissue/drug effects
- Adipose Tissue/metabolism
- Animals
- Blood Glucose/drug effects
- Blood Glucose/metabolism
- Blotting, Western
- Body Composition
- Brain/drug effects
- Brain/metabolism
- Carbon Radioisotopes
- Deoxyglucose
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 2/metabolism
- Diet, High-Fat
- Disease Models, Animal
- Ependymoglial Cells/drug effects
- Ependymoglial Cells/metabolism
- Fibroblast Growth Factor 1/pharmacology
- Forkhead Box Protein O1/genetics
- Glucose Tolerance Test
- Heart/drug effects
- Heat-Shock Proteins/drug effects
- Heat-Shock Proteins/metabolism
- Hyperglycemia/metabolism
- Hypothalamus/cytology
- Hypothalamus/drug effects
- Hypothalamus/metabolism
- Injections, Intraventricular
- Liver/metabolism
- Male
- Mice
- Mice, Knockout
- Mice, Obese
- Molecular Chaperones
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Myocardium/metabolism
- Neoplasm Proteins/drug effects
- Neoplasm Proteins/metabolism
- Proto-Oncogene Proteins c-fos/drug effects
- Proto-Oncogene Proteins c-fos/metabolism
- Rats
- Rats, Zucker
- Real-Time Polymerase Chain Reaction
- Receptor, Insulin/antagonists & inhibitors
- Receptor, Insulin/genetics
- Remission Induction
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Affiliation(s)
- Jarrad M Scarlett
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
- Department of Pediatric Gastroenterology and Hepatology, Seattle Children's Hospital, Seattle, Washington, USA
| | - Jennifer M Rojas
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Miles E Matsen
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Karl J Kaiyala
- Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, Washington, USA
| | - Darko Stefanovski
- New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Richard N Bergman
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Hong T Nguyen
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Mauricio D Dorfman
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | - Zaman Mirzadeh
- Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA
| | - Terry G Unterman
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
- Medical Service, Jesse Brown Virginia Medical Center, Chicago, Illinois, USA
| | - Gregory J Morton
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Michael W Schwartz
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
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25
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Beshara S, Beston BR, Pinto JGA, Murphy KM. Effects of Fluoxetine and Visual Experience on Glutamatergic and GABAergic Synaptic Proteins in Adult Rat Visual Cortex. eNeuro 2015; 2:ENEURO.0126-15.2015. [PMID: 26730408 PMCID: PMC4698542 DOI: 10.1523/eneuro.0126-15.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/04/2015] [Accepted: 12/08/2015] [Indexed: 01/12/2023] Open
Abstract
Fluoxetine has emerged as a novel treatment for persistent amblyopia because in adult animals it reinstates critical period-like ocular dominance plasticity and promotes recovery of visual acuity. Translation of these results from animal models to the clinic, however, has been challenging because of the lack of understanding of how this selective serotonin reuptake inhibitor affects glutamatergic and GABAergic synaptic mechanisms that are essential for experience-dependent plasticity. An appealing hypothesis is that fluoxetine recreates a critical period (CP)-like state by shifting synaptic mechanisms to be more juvenile. To test this we studied the effect of fluoxetine treatment in adult rats, alone or in combination with visual deprivation [monocular deprivation (MD)], on a set of highly conserved presynaptic and postsynaptic proteins (synapsin, synaptophysin, VGLUT1, VGAT, PSD-95, gephyrin, GluN1, GluA2, GluN2B, GluN2A, GABAAα1, GABAAα3). We did not find evidence that fluoxetine shifted the protein amounts or balances to a CP-like state. Instead, it drove the balances in favor of the more mature subunits (GluN2A, GABAAα1). In addition, when fluoxetine was paired with MD it created a neuroprotective-like environment by normalizing the glutamatergic gain found in adult MDs. Together, our results suggest that fluoxetine treatment creates a novel synaptic environment dominated by GluN2A- and GABAAα1-dependent plasticity.
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Affiliation(s)
- Simon Beshara
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Brett R. Beston
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, Ontario L8S 4K1, Canada
- Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, Ontario L8S 4K1, Canada
- Department of Psychology, University of Toronto Mississauga, Mississauga, L5L 1C6, ON
| | - Joshua G. A. Pinto
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, Ontario L8S 4K1, Canada
- Health Care Investment Banking, Credit Suisse AG, San Francisco, CA 94108
| | - Kathryn M. Murphy
- McMaster Integrative Neuroscience Discovery and Study (MiNDS) Program, McMaster University, Hamilton, Ontario L8S 4K1, Canada
- Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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26
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Siu CR, Balsor JL, Jones DG, Murphy KM. Classic and Golli Myelin Basic Protein have distinct developmental trajectories in human visual cortex. Front Neurosci 2015; 9:138. [PMID: 25964736 PMCID: PMC4408849 DOI: 10.3389/fnins.2015.00138] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 04/02/2015] [Indexed: 01/03/2023] Open
Abstract
Traditionally, myelin is viewed as insulation around axons, however, more recent studies have shown it also plays an important role in plasticity, axonal metabolism, and neuroimmune signaling. Myelin is a complex multi-protein structure composed of hundreds of proteins, with Myelin Basic Protein (MBP) being the most studied. MBP has two families: Classic-MBP that is necessary for activity driven compaction of myelin around axons, and Golli-MBP that is found in neurons, oligodendrocytes, and T-cells. Furthermore, Golli-MBP has been called a “molecular link” between the nervous and immune systems. In visual cortex specifically, myelin proteins interact with immune processes to affect experience-dependent plasticity. We studied myelin in human visual cortex using Western blotting to quantify Classic- and Golli-MBP expression in post-mortem tissue samples ranging in age from 20 days to 80 years. We found that Classic- and Golli-MBP have different patterns of change across the lifespan. Classic-MBP gradually increases to 42 years and then declines into aging. Golli-MBP has early developmental changes that are coincident with milestones in visual system sensitive period, and gradually increases into aging. There are three stages in the balance between Classic- and Golli-MBP expression, with Golli-MBP dominating early, then shifting to Classic-MBP, and back to Golli-MBP in aging. Also Golli-MBP has a wave of high inter-individual variability during childhood. These results about cortical MBP expression are timely because they compliment recent advances in MRI techniques that produce high resolution maps of cortical myelin in normal and diseased brain. In addition, the unique pattern of Golli-MBP expression across the lifespan suggests that it supports high levels of neuroimmune interaction in cortical development and in aging.
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Affiliation(s)
- Caitlin R Siu
- McMaster Integrative Neuroscience Discovery and Study Program, McMaster University Hamilton, ON, Canada
| | - Justin L Balsor
- McMaster Integrative Neuroscience Discovery and Study Program, McMaster University Hamilton, ON, Canada
| | | | - Kathryn M Murphy
- McMaster Integrative Neuroscience Discovery and Study Program, McMaster University Hamilton, ON, Canada ; Psychology, Neuroscience and Behaviour, McMaster University Hamilton, ON, Canada
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