1
|
Kaizuka T, Takumi T. Alteration of synaptic protein composition during developmental synapse maturation. Eur J Neurosci 2024; 59:2894-2914. [PMID: 38571321 DOI: 10.1111/ejn.16304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 01/02/2024] [Accepted: 02/07/2024] [Indexed: 04/05/2024]
Abstract
The postsynaptic density (PSD) is a collection of specialized proteins assembled beneath the postsynaptic membrane of dendritic spines. The PSD proteome comprises ~1000 proteins, including neurotransmitter receptors, scaffolding proteins and signalling enzymes. Many of these proteins have essential roles in synaptic function and plasticity. During brain development, changes are observed in synapse density and in the stability and shape of spines, reflecting the underlying molecular maturation of synapses. Synaptic protein composition changes in terms of protein abundance and the assembly of protein complexes, supercomplexes and the physical organization of the PSD. Here, we summarize the developmental alterations of postsynaptic protein composition during synapse maturation. We describe major PSD proteins involved in postsynaptic signalling that regulates synaptic plasticity and discuss the effect of altered expression of these proteins during development. We consider the abnormality of synaptic profiles and synaptic protein composition in the brain in neurodevelopmental disorders such as autism spectrum disorders. We also explain differences in synapse development between rodents and primates in terms of synaptic profiles and protein composition. Finally, we introduce recent findings related to synaptic diversity and nanoarchitecture and discuss their impact on future research. Synaptic protein composition can be considered a major determinant and marker of synapse maturation in normality and disease.
Collapse
Affiliation(s)
- Takeshi Kaizuka
- Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Toru Takumi
- Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
- RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| |
Collapse
|
2
|
Akhgari A, Michel TM, Vafaee MS. Dendritic spines and their role in the pathogenesis of neurodevelopmental and neurological disorders. Rev Neurosci 2024; 0:revneuro-2023-0151. [PMID: 38440811 DOI: 10.1515/revneuro-2023-0151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 02/02/2024] [Indexed: 03/06/2024]
Abstract
Since Cajal introduced dendritic spines in the 19th century, they have attained considerable attention, especially in neuropsychiatric and neurologic disorders. Multiple roles of dendritic spine malfunction and pathology in the progression of various diseases have been reported. Thus, it is inevitable to consider these structures as new therapeutic targets for treating neuropsychiatric and neurologic disorders such as autism spectrum disorders, schizophrenia, dementia, Down syndrome, etc. Therefore, we attempted to prepare a narrative review of the literature regarding the role of dendritic spines in the pathogenesis of aforementioned diseases and to shed new light on their pathophysiology.
Collapse
Affiliation(s)
- Aisan Akhgari
- Student Research Committee, Tabriz University of Medical Sciences, Golgasht Street, Tabriz 5166616471, Iran
| | - Tanja Maria Michel
- Research Unit for Psychiatry, Odense University Hospital, J. B. Winsløws Vej 4, Odense 5000, Denmark
- Clinical Institute, University of Southern Denmark, Campusvej 55, Odense 5230, Denmark
| | - Manouchehr Seyedi Vafaee
- Research Unit for Psychiatry, Odense University Hospital, J. B. Winsløws Vej 4, Odense 5000, Denmark
- Clinical Institute, University of Southern Denmark, Campusvej 55, Odense 5230, Denmark
| |
Collapse
|
3
|
Sun H, Lai HM, Wu W. Three-dimensional visualization and analysis of dendritic spines in human brain tissue. Biotechniques 2024; 76:37-42. [PMID: 37994419 DOI: 10.2144/btn-2023-0078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023] Open
Abstract
We developed a simple yet powerful technique to visualize neuronal morphology in human brain tissues. By ballistically shooting DiI (1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate)-coated tungsten particles to randomly label neurons, then clearing tissues with OPTIClear, we demonstrated the tracing of branched dendritic trees and spines in three dimensions. High-resolution imaging revealed dendrites up to 300 μm long and spine necks down to 200 nm across. Quantitative analyses of 1304 dendritic spines showed no decrease in spine density with imaging depth, indicating excellent clearing and tracing. Segmentation and modeling of dendritic spines enabled morphological characterization. This technique enables assumption-free, high-resolution and cost-efficient visualization of neuronal morphology in human tissues. Combined with immunohistochemistry and electron microscopy, it could provide new perspectives for studying human neuroanatomy and pathology.
Collapse
Affiliation(s)
- Haitao Sun
- Clinical Biobank Center, Microbiome Medicine Center, Department of Laboratory Medicine, Guangdong Provincial Clinical Research Center for Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- Neurosurgery Center, The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China on Diagnosis & Treatment of Cerebrovascular Disease, Guangdong Provincial Key Laboratory on Brain Function Repair & Regeneration, The Neurosurgery Institute of Guangdong Province Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Hei Ming Lai
- Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Wutian Wu
- Re-Stem Biotechnology, Suzhou, Jiangsu, China
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
| |
Collapse
|
4
|
Granak S, Tuckova K, Kutna V, Vojtechova I, Bajkova L, Petrasek T, Ovsepian SV. Developmental effects of constitutive mTORC1 hyperactivity and environmental enrichment on structural synaptic plasticity and behaviour in a rat model of autism spectrum disorder. Eur J Neurosci 2023; 57:17-31. [PMID: 36380588 DOI: 10.1111/ejn.15864] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 09/18/2022] [Accepted: 11/09/2022] [Indexed: 11/17/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition causing a range of social and communication impairments. Although the role of multiple genes and environmental factors has been reported, the effects of the interplay between genes and environment on the onset and progression of the disease remains elusive. We housed wild-type (Tsc2+/+) and tuberous sclerosis 2 deficient (Tsc2+/-) Eker rats (ASD model) in individually ventilated cages or enriched conditions and conducted a series of behavioural tests followed by the histochemical analysis of dendritic spines and plasticity in three age groups (days 45, 90 and 365). The elevated plus-maze test revealed a reduction of anxiety by enrichment, whereas the mobility of young and adult Eker rats in the open field was lower compared to the wild type. In the social interaction test, an enriched environment reduced social contact in the youngest group and increased anogenital exploration in 90- and 365-day-old rats. Self-grooming was increased by environmental enrichment in young and adult rats and decreased in aged Eker rats. Dendritic spine counts revealed an increased spine density in the cingulate gyrus in adult Ekers irrespective of housing conditions, whereas spine density in hippocampal pyramidal neurons was comparable across all genotypes and groups. Morphometric analysis of dendritic spines revealed age-related changes in spine morphology and density, which were responsive to animal genotype and environment. Taken together, our findings suggest that under TSC2 haploinsufficiency and mTORC1 hyperactivity, the expression of behavioural signs and neuroplasticity in Eker rats can be differentially influenced by the developmental stage and environment.
Collapse
Affiliation(s)
- Simon Granak
- National Institute of Mental Health, Klecany, Czech Republic.,Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Klara Tuckova
- National Institute of Mental Health, Klecany, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Viera Kutna
- National Institute of Mental Health, Klecany, Czech Republic
| | - Iveta Vojtechova
- National Institute of Mental Health, Klecany, Czech Republic.,Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Laura Bajkova
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Tomas Petrasek
- National Institute of Mental Health, Klecany, Czech Republic.,Laboratory of Neurophysiology of Memory, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Saak V Ovsepian
- Faculty of Science and Engineering, University of Greenwich London, Chatham Maritime, UK
| |
Collapse
|
5
|
Rasia-Filho AA, Calcagnotto ME, von Bohlen Und Halbach O. Introduction: What Are Dendritic Spines? ADVANCES IN NEUROBIOLOGY 2023; 34:1-68. [PMID: 37962793 DOI: 10.1007/978-3-031-36159-3_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Dendritic spines are cellular specializations that greatly increase the connectivity of neurons and modulate the "weight" of most postsynaptic excitatory potentials. Spines are found in very diverse animal species providing neural networks with a high integrative and computational possibility and plasticity, enabling the perception of sensorial stimuli and the elaboration of a myriad of behavioral displays, including emotional processing, memory, and learning. Humans have trillions of spines in the cerebral cortex, and these spines in a continuum of shapes and sizes can integrate the features that differ our brain from other species. In this chapter, we describe (1) the discovery of these small neuronal protrusions and the search for the biological meaning of dendritic spines; (2) the heterogeneity of shapes and sizes of spines, whose structure and composition are associated with the fine-tuning of synaptic processing in each nervous area, as well as the findings that support the role of dendritic spines in increasing the wiring of neural circuits and their functions; and (3) within the intraspine microenvironment, the integration and activation of signaling biochemical pathways, the compartmentalization of molecules or their spreading outside the spine, and the biophysical properties that can affect parent dendrites. We also provide (4) examples of plasticity involving dendritic spines and neural circuits relevant to species survival and comment on (5) current research advancements and challenges in this exciting research field.
Collapse
Affiliation(s)
- Alberto A Rasia-Filho
- Department of Basic Sciences/Physiology and Graduate Program in Biosciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Maria Elisa Calcagnotto
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Graduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Graduate Program in Psychiatry and Behavioral Science, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | | |
Collapse
|
6
|
Guerra KTK, Renner J, Vásquez CE, Rasia‐Filho AA. Human cortical amygdala dendrites and spines morphology under open‐source three‐dimensional reconstruction procedures. J Comp Neurol 2022; 531:344-365. [PMID: 36355397 DOI: 10.1002/cne.25430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 10/05/2022] [Accepted: 10/14/2022] [Indexed: 11/12/2022]
Abstract
Visualizing nerve cells has been fundamental for the systematic description of brain structure and function in humans and other species. Different approaches aimed to unravel the morphological features of neuron types and diversity. The inherent complexity of the human nervous tissue and the need for proper histological processing have made studying human dendrites and spines challenging in postmortem samples. In this study, we used Golgi data and open-source software for 3D image reconstruction of human neurons from the cortical amygdaloid nucleus to show different dendrites and pleomorphic spines at different angles. Procedures required minimal equipment and generated high-quality images for differently shaped cells. We used the "single-section" Golgi method adapted for the human brain to engender 3D reconstructed images of the neuronal cell body and the dendritic ramification by adopting a neuronal tracing procedure. In addition, we elaborated 3D reconstructions to visualize heterogeneous dendritic spines using a supervised machine learning-based algorithm for image segmentation. These tools provided an additional upgrade and enhanced visual display of information related to the spatial orientation of dendritic branches and for dendritic spines of varied sizes and shapes in these human subcortical neurons. This same approach can be adapted for other techniques, areas of the central or peripheral nervous system, and comparative analysis between species.
Collapse
Affiliation(s)
- Kétlyn T. Knak Guerra
- Graduate Program in Neuroscience Universidade Federal do Rio Grande do Sul Porto Alegre Brazil
| | - Josué Renner
- Department of Basic Sciences/Physiology Universidade Federal de Ciências da Saúde de Porto Alegre Porto Alegre Brazil
- Graduate Program in Biosciences Universidade Federal de Ciências da Saúde de Porto Alegre Porto Alegre Brazil
| | - Carlos E. Vásquez
- Graduate Program in Neuroscience Universidade Federal do Rio Grande do Sul Porto Alegre Brazil
| | - Alberto A. Rasia‐Filho
- Graduate Program in Neuroscience Universidade Federal do Rio Grande do Sul Porto Alegre Brazil
- Department of Basic Sciences/Physiology Universidade Federal de Ciências da Saúde de Porto Alegre Porto Alegre Brazil
- Graduate Program in Biosciences Universidade Federal de Ciências da Saúde de Porto Alegre Porto Alegre Brazil
| |
Collapse
|
7
|
Prikas E, Paric E, Asih PR, Stefanoska K, Stefen H, Fath T, Poljak A, Ittner A. Tau target identification reveals NSF-dependent effects on AMPA receptor trafficking and memory formation. EMBO J 2022; 41:e10242. [PMID: 35993331 PMCID: PMC9475529 DOI: 10.15252/embj.2021110242] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 07/03/2022] [Accepted: 07/18/2022] [Indexed: 11/09/2022] Open
Abstract
Microtubule-associated protein tau is a central factor in Alzheimer's disease and other tauopathies. However, the physiological functions of tau are unclear. Here, we used proximity-labelling proteomics to chart tau interactomes in primary neurons and mouse brains in vivo. Tau interactors map onto pathways of cytoskeletal, synaptic vesicle and postsynaptic receptor regulation and show significant enrichment for Parkinson's, Alzheimer's and prion disease. We find that tau interacts with and dose-dependently reduces the activity of N-ethylmaleimide sensitive fusion protein (NSF), a vesicular ATPase essential for AMPA-type glutamate receptor (AMPAR) trafficking. Tau-deficient (tau-/- ) neurons showed mislocalised expression of NSF and enhanced synaptic AMPAR surface levels, reversible through the expression of human tau or inhibition of NSF. Consequently, enhanced AMPAR-mediated associative and object recognition memory in tau-/- mice is suppressed by both hippocampal tau and infusion with an NSF-inhibiting peptide. Pathologic mutant tau from mouse models or Alzheimer's disease significantly enhances NSF inhibition. Our results map neuronal tau interactomes and delineate a functional link of tau with NSF in plasticity-associated AMPAR-trafficking and memory.
Collapse
Affiliation(s)
- Emmanuel Prikas
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
| | - Esmeralda Paric
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human SciencesMacquarie UniversitySydneyNSWAustralia
| | - Prita R Asih
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
| | - Kristie Stefanoska
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
| | - Holly Stefen
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human SciencesMacquarie UniversitySydneyNSWAustralia
| | - Thomas Fath
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human SciencesMacquarie UniversitySydneyNSWAustralia
| | - Anne Poljak
- Mark Wainwright Analytical CentreUniversity of New South WalesSydneyNSWAustralia
| | - Arne Ittner
- Flinders Health & Medical Research Institute, College of Medicine and Public HealthFlinders UniversityAdelaideSAAustralia
| |
Collapse
|
8
|
Walker CK, Greathouse KM, Liu E, Muhammad HM, Boros BD, Freeman CD, Seo JV, Herskowitz JH. Comparison of Golgi-Cox and Intracellular Loading of Lucifer Yellow for Dendritic Spine Density and Morphology Analysis in the Mouse Brain. Neuroscience 2022; 498:1-18. [PMID: 35752428 PMCID: PMC9420811 DOI: 10.1016/j.neuroscience.2022.06.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 10/17/2022]
Abstract
Dendritic spines are small protrusions on dendrites that serve as the postsynaptic site of the majority of excitatory synapses. These structures are important for normal synaptic transmission, and alterations in their density and morphology have been documented in various disease states. Over 130 years ago, Ramón y Cajal used Golgi-stained tissue sections to study dendritic morphology. Despite the array of technological advances, including iontophoretic microinjection of Lucifer yellow (LY) fluorescent dye, Golgi staining continues to be one of the most popular approaches to visualize dendritic spines. Here, we compared dendritic spine density and morphology among pyramidal neurons in layers 2/3 of the mouse medial prefrontal cortex (mPFC) and pyramidal neurons in hippocampal CA1 using three-dimensional digital reconstructions of (1) brightfield microscopy z-stacks of Golgi-impregnated dendrites and (2) confocal microscopy z-stacks of LY-filled dendrites. Analysis of spine density revealed that the LY microinjection approach enabled detection of approximately three times as many spines as the Golgi staining approach in both brain regions. Spine volume measurements were larger using Golgi staining compared to LY microinjection in both mPFC and CA1. Spine length was mostly comparable between techniques in both regions. In the mPFC, head diameter was similar for Golgi staining and LY microinjection. However, in CA1, head diameter was approximately 50% smaller on LY-filled dendrites compared to Golgi staining. These results indicate that Golgi staining and LY microinjection yield different spine density and morphology measurements, with Golgi staining failing to detect dendritic spines and overestimating spine size.
Collapse
Affiliation(s)
- Courtney K Walker
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Kelsey M Greathouse
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Evan Liu
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Hamad M Muhammad
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Benjamin D Boros
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Cameron D Freeman
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Jung Vin Seo
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Jeremy H Herskowitz
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA.
| |
Collapse
|
9
|
Chaudry S, Vasudevan N. mTOR-Dependent Spine Dynamics in Autism. Front Mol Neurosci 2022; 15:877609. [PMID: 35782388 PMCID: PMC9241970 DOI: 10.3389/fnmol.2022.877609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/25/2022] [Indexed: 12/12/2022] Open
Abstract
Autism Spectrum Conditions (ASC) are a group of neurodevelopmental disorders characterized by deficits in social communication and interaction as well as repetitive behaviors and restricted range of interests. ASC are complex genetic disorders with moderate to high heritability, and associated with atypical patterns of neural connectivity. Many of the genes implicated in ASC are involved in dendritic spine pruning and spine development, both of which can be mediated by the mammalian target of rapamycin (mTOR) signaling pathway. Consistent with this idea, human postmortem studies have shown increased spine density in ASC compared to controls suggesting that the balance between autophagy and spinogenesis is altered in ASC. However, murine models of ASC have shown inconsistent results for spine morphology, which may underlie functional connectivity. This review seeks to establish the relevance of changes in dendritic spines in ASC using data gathered from rodent models. Using a literature survey, we identify 20 genes that are linked to dendritic spine pruning or development in rodents that are also strongly implicated in ASC in humans. Furthermore, we show that all 20 genes are linked to the mTOR pathway and propose that the mTOR pathway regulating spine dynamics is a potential mechanism underlying the ASC signaling pathway in ASC. We show here that the direction of change in spine density was mostly correlated to the upstream positive or negative regulation of the mTOR pathway and most rodent models of mutant mTOR regulators show increases in immature spines, based on morphological analyses. We further explore the idea that these mutations in these genes result in aberrant social behavior in rodent models that is due to these altered spine dynamics. This review should therefore pave the way for further research on the specific genes outlined, their effect on spine morphology or density with an emphasis on understanding the functional role of these changes in ASC.
Collapse
|
10
|
Serrano ME, Kim E, Petrinovic MM, Turkheimer F, Cash D. Imaging Synaptic Density: The Next Holy Grail of Neuroscience? Front Neurosci 2022; 16:796129. [PMID: 35401097 PMCID: PMC8990757 DOI: 10.3389/fnins.2022.796129] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/15/2022] [Indexed: 12/19/2022] Open
Abstract
The brain is the central and most complex organ in the nervous system, comprising billions of neurons that constantly communicate through trillions of connections called synapses. Despite being formed mainly during prenatal and early postnatal development, synapses are continually refined and eliminated throughout life via complicated and hitherto incompletely understood mechanisms. Failure to correctly regulate the numbers and distribution of synapses has been associated with many neurological and psychiatric disorders, including autism, epilepsy, Alzheimer’s disease, and schizophrenia. Therefore, measurements of brain synaptic density, as well as early detection of synaptic dysfunction, are essential for understanding normal and abnormal brain development. To date, multiple synaptic density markers have been proposed and investigated in experimental models of brain disorders. The majority of the gold standard methodologies (e.g., electron microscopy or immunohistochemistry) visualize synapses or measure changes in pre- and postsynaptic proteins ex vivo. However, the invasive nature of these classic methodologies precludes their use in living organisms. The recent development of positron emission tomography (PET) tracers [such as (18F)UCB-H or (11C)UCB-J] that bind to a putative synaptic density marker, the synaptic vesicle 2A (SV2A) protein, is heralding a likely paradigm shift in detecting synaptic alterations in patients. Despite their limited specificity, novel, non-invasive magnetic resonance (MR)-based methods also show promise in inferring synaptic information by linking to glutamate neurotransmission. Although promising, all these methods entail various advantages and limitations that must be addressed before becoming part of routine clinical practice. In this review, we summarize and discuss current ex vivo and in vivo methods of quantifying synaptic density, including an evaluation of their reliability and experimental utility. We conclude with a critical assessment of challenges that need to be overcome before successfully employing synaptic density biomarkers as diagnostic and/or prognostic tools in the study of neurological and neuropsychiatric disorders.
Collapse
Affiliation(s)
- Maria Elisa Serrano
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Eugene Kim
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Marija M Petrinovic
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Diana Cash
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| |
Collapse
|
11
|
Dudink I, White TA, Ardalan M, Mallard C, Ballerin G, Creed SJ, Pham Y, Sutherland AE, Castillo-Melendez M, Allison BJ, Miller SL. An optimized and detailed step-by-step protocol for the analysis of neuronal morphology in golgi-stained fetal sheep brain. Dev Neurosci 2022; 44:344-362. [DOI: 10.1159/000524055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/07/2022] [Indexed: 11/19/2022] Open
Abstract
Antenatal brain development during the final trimester of human pregnancy is a time when mature neurons become increasingly complex in morphology, through axonal and dendritic outgrowth, dendritic branching, and synaptogenesis, together with myelin production. Characterizing neuronal morphological development over time is of interest to developmental neuroscience and provides the framework to measure grey matter pathology in pregnancy compromise. Neuronal microstructure can be assessed with Golgi staining, which selectively stains a small percentage (1-3%) of neurons and their entire dendritic arbor. Advanced imaging processing and analysis tools can then be employed to quantitate neuronal cytoarchitecture. Traditional Golgi staining protocols have been optimized and commercial kits are readily available offering improved speed and sensitivity of Golgi staining to produce consistent results. Golgi stained tissue is then visualized under light microscopy and image analysis may be completed with several software programs for morphological analysis of neurons, including freeware and commercial products. Each program requires optimization, whether semi-automated or automated, requiring different levels of investigator intervention and interpretation, which is a critical consideration for unbiased analysis. Detailed protocols for fetal ovine brain tissue are lacking and therefore, we provide a step-by-step workflow of computer software analysis for morphometric quantification of Golgi-stained neurons. Here, we utilized the commonly applied FD Rapid GolgiStain kit (FD NeuroTechnologies) on ovine fetal brains collected at 127 days (0.85) gestational age for the analysis of CA1 pyramidal neurons in the hippocampus. We describe the step-by-step protocol to retrieve neuronal morphometrics using Imaris imaging software to provide quantification of apical and basal dendrites for measures of dendrite length (μm), branch number, branch order and Sholl analysis (intersections over radius). We also detail software add-ons for data retrieval of dendritic spines including the number of spines, spine density and spine classification, which are critical indicators of synaptic function. The assessment of neuronal morphology in the developing brain using Rapid-Golgi and Imaris software is labour-intensive, particularly during the optimization period. The methodology described in this step-by-step description is novel, detailed, and aims to provide a reproducible, working protocol to quantify neuronal cytoarchitecture with simple descriptions that will save time for the next users of these commonly used techniques.
Collapse
|
12
|
A Novel Estimation Method for the Counting of Dendritic Spines. J Neurosci Methods 2021; 368:109454. [PMID: 34952089 DOI: 10.1016/j.jneumeth.2021.109454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 11/21/2022]
Abstract
BACKGROUND Since Cajal's visualisations of the synaptic spine, this feature of the neuron has been of interest to neuroscientists and has been investigated usually in reference to degeneration or proliferation of dendrites and their neurons. Synaptic spine measurement often forms a critical element of any study investigating neuronal morphology. However, the way researchers have counted spines hasn't changed for almost a century. Some of the currently used legacy methods fail to accommodate obscured pisnes or factor-in visibility differences between histological stains. NEW METHOD Here we investigate the neuronal dendrite and its synaptic spines, and reveal that using confocal or bright-field technologies may in fact obfuscate spine counts. A mathematical model is developed for the distribution of synaptic spines within the rat, that should, by nature of the formula and the impartiality of probability quotients, be applied to estimate the number of synaptic spines across any length of dendrite that has protrusions within any species. RESULTS Using this estimation method, we show that, depending on the method of image capture, there are in fact more spines present than typically counted on lengths of dendrite, something that may have biased morphological studies in the past. COMPARISON WITH EXISTING METHODS This new estimation method has been collapsed down into an easy-to-use free website. With input of only four fields, we provide the researcher with a more accurate estimation of the amount of spines on a length of dendrite. This was made possible by fluorescing a Golgi stain and comparing two-photon, bright-field and confocal images. CONCLUSIONS An easy web-based resource has been made available to use this new method for spine calculation. Using this method improves the validity of spine measurement and provides a means to review previously published work.
Collapse
|
13
|
Miller MQ, Hernández IC, Chacko JV, Minderler S, Jowett N. Two-photon excitation fluorescent spectral and decay properties of retrograde neuronal tracer Fluoro-Gold. Sci Rep 2021; 11:18053. [PMID: 34508127 PMCID: PMC8433443 DOI: 10.1038/s41598-021-97562-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 08/26/2021] [Indexed: 11/14/2022] Open
Abstract
Fluoro-Gold is a fluorescent neuronal tracer suitable for targeted deep imaging of the nervous system. Widefield fluorescence microscopy enables visualization of Fluoro-Gold, but lacks depth discrimination. Though scanning laser confocal microscopy yields volumetric data, imaging depth is limited, and optimal single-photon excitation of Fluoro-Gold requires an unconventional ultraviolet excitation line. Two-photon excitation microscopy employs ultrafast pulsed infrared lasers to image fluorophores at high-resolution at unparalleled depths in opaque tissue. Deep imaging of Fluoro-Gold-labeled neurons carries potential to advance understanding of the central and peripheral nervous systems, yet its two-photon spectral and temporal properties remain uncharacterized. Herein, we report the two-photon excitation spectrum of Fluoro-Gold between 720 and 990 nm, and its fluorescence decay rate in aqueous solution and murine brainstem tissue. We demonstrate unprecedented imaging depth of whole-mounted murine brainstem via two-photon excitation microscopy of Fluoro-Gold labeled facial motor nuclei. Optimal two-photon excitation of Fluoro-Gold within microscope tuning range occurred at 720 nm, while maximum lifetime contrast was observed at 760 nm with mean fluorescence lifetime of 1.4 ns. Whole-mount brainstem explants were readily imaged to depths in excess of 450 µm via immersion in refractive-index matching solution.
Collapse
Affiliation(s)
- Matthew Q Miller
- Surgical Photonics and Engineering Laboratory, Massachusetts Eye and Ear, Harvard Medical School, 243 Charles Street, Boston, MA, 02114, USA.,Department of Otolaryngology/Head and Neck Surgery, University of North Carolina Health Care, Chapel Hill, NC, USA
| | - Iván Coto Hernández
- Surgical Photonics and Engineering Laboratory, Massachusetts Eye and Ear, Harvard Medical School, 243 Charles Street, Boston, MA, 02114, USA.
| | - Jenu V Chacko
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin, Madison, WI, USA
| | - Steven Minderler
- Surgical Photonics and Engineering Laboratory, Massachusetts Eye and Ear, Harvard Medical School, 243 Charles Street, Boston, MA, 02114, USA
| | - Nate Jowett
- Surgical Photonics and Engineering Laboratory, Massachusetts Eye and Ear, Harvard Medical School, 243 Charles Street, Boston, MA, 02114, USA.
| |
Collapse
|
14
|
Li C, Shi J, Sun J, Shi Y, Jia H. Cannabinoid receptor 2 deficiency enhances isoflurane-induced spatial cognitive impairment in adult mice by affecting neuroinflammation, neurogenesis and neuroplasticity. Exp Ther Med 2021; 22:908. [PMID: 34257720 PMCID: PMC8243338 DOI: 10.3892/etm.2021.10340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/21/2021] [Indexed: 12/15/2022] Open
Abstract
Isoflurane (Iso) is a commonly used inhalational anesthetic and is associated with the incidence of postoperative cognitive dysfunction (POCD). Cannabinoid receptor 2 (CB2R) was previously reported to have a promising neuroprotective function in cases of POCD, but the specific mechanisms have remained to be fully explored. The aim of the present study was to investigate the effect of CB2R deficiency on spatial cognitive performance in adult mice exposed to Iso. A total of 20 adult CB2R knockout (KO) and 20 wild-type (WT) mice were exposed to Iso (1.4% in oxygen for 4 h) or 100% oxygen. The Morris water maze (MWZ) test was performed 10 days after Iso exposure. Immunofluorescence staining and reverse transcription-quantitative PCR were performed to assess the expression of microglial marker ionized calcium-binding adaptor molecule-1 (Iba1) and the mRNA expression levels of microglial phenotype markers (M1: Interleukin-6, tumor necrosis factor-α, inducible nitric oxide synthase; M2: Chitinase-3 like protein) in the hippocampus. Changes in hippocampal neurogenesis and neuroplasticity were assessed by 5-bromodeoxyuridine (BrdU) immunostaining and Golgi staining. Compared with control mice, WT Iso-exposed mice had impaired spatial performance in the MWZ test. Furthermore, hippocampal Iba1 immunoreactivity and the number of microglial branches were notably increased in Iso-exposed WT mice. This was paralleled by significant upregulation of M1-associated markers and downregulation of M2-associated markers in the hippocampus. An obviously reduced number of BrdU+ neurons and decreased spine density were observed in WT Iso-exposed mice compared with control mice. Of note, CB2R deficiency exacerbated the spatial cognition impairment induced by Iso in the MWZ test. The alterations in the activation, morphology and M1 polarization of microglia, the number of BrdU+ neurons and spine density were more pronounced in CB2R-deficient Iso-exposed KO mice than in WT Iso-exposed mice. These results suggested that CB2R has a crucial role in Iso-induced cognitive impairment, which may be related to changes in hippocampal neuroinflammation, neurogenesis and neuroplasticity.
Collapse
Affiliation(s)
- Chao Li
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jingpu Shi
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jiaguang Sun
- Department of Anesthesiology, Xingtai People's Hospital, Xintai, Hebei 054001, P.R. China
| | - Yuanyuan Shi
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Huiqun Jia
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| |
Collapse
|
15
|
Benedetti B, Dannehl D, König R, Coviello S, Kreutzer C, Zaunmair P, Jakubecova D, Weiger TM, Aigner L, Nacher J, Engelhardt M, Couillard-Després S. Functional Integration of Neuronal Precursors in the Adult Murine Piriform Cortex. Cereb Cortex 2021; 30:1499-1515. [PMID: 31647533 PMCID: PMC7132906 DOI: 10.1093/cercor/bhz181] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 06/05/2019] [Accepted: 07/09/2019] [Indexed: 11/20/2022] Open
Abstract
The extent of functional maturation and integration of nonproliferative neuronal precursors, becoming neurons in the adult murine piriform cortex, is largely unexplored. We thus questioned whether precursors eventually become equivalent to neighboring principal neurons or whether they represent a novel functional network element. Adult brain neuronal precursors and immature neurons (complex cells) were labeled in transgenic mice (DCX-DsRed and DCX-CreERT2 /flox-EGFP), and their cell fate was characterized with patch clamp experiments and morphometric analysis of axon initial segments. Young (DCX+) complex cells in the piriform cortex of 2- to 4-month-old mice received sparse synaptic input and fired action potentials at low maximal frequency, resembling neonatal principal neurons. Following maturation, the synaptic input detected on older (DCX−) complex cells was larger, but predominantly GABAergic, despite evidence of glutamatergic synaptic contacts. Furthermore, the rheobase current of old complex cells was larger and the maximal firing frequency was lower than those measured in neighboring age-matched principal neurons. The striking differences between principal neurons and complex cells suggest that the latter are a novel type of neuron and new coding element in the adult brain rather than simple addition or replacement for preexisting network components.
Collapse
Affiliation(s)
- Bruno Benedetti
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Dominik Dannehl
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Institute of Neuroanatomy, CBTM, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Richard König
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Simona Coviello
- BIOTECMED, Universitat de València and Center for Collaborative Research on Mental Health CIBERSAM, 46100 València, Spain
| | - Christina Kreutzer
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Pia Zaunmair
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Dominika Jakubecova
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Thomas M Weiger
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria
| | - Ludwig Aigner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Juan Nacher
- BIOTECMED, Universitat de València and Center for Collaborative Research on Mental Health CIBERSAM, 46100 València, Spain
| | - Maren Engelhardt
- Institute of Neuroanatomy, CBTM, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Sébastien Couillard-Després
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| |
Collapse
|
16
|
Jiang L, Cao Y, Yin X, Ni S, Li M, Li C, Luo Z, Lu H, Hu J. A combinatorial method to visualize the neuronal network in the mouse spinal cord: combination of a modified Golgi-Cox method and synchrotron radiation micro-computed tomography. Histochem Cell Biol 2021; 155:477-489. [PMID: 33398435 PMCID: PMC8062354 DOI: 10.1007/s00418-020-01949-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2020] [Indexed: 12/23/2022]
Abstract
Exploring the three-dimensional (3D) morphology of neurons is essential to understanding spinal cord function and associated diseases comprehensively. However, 3D imaging of the neuronal network in the broad region of the spinal cord at cellular resolution remains a challenge in the field of neuroscience. In this study, to obtain high-resolution 3D imaging of a detailed neuronal network in the mass of the spinal cord, the combination of synchrotron radiation micro-computed tomography (SRμCT) and the Golgi-cox staining were used. We optimized the Golgi-Cox method (GCM) and developed a modified GCM (M-GCM), which improved background staining, reduced the number of artefacts, and diminished the impact of incomplete vasculature compared to the current GCM. Moreover, we achieved high-resolution 3D imaging of the detailed neuronal network in the spinal cord through the combination of SRμCT and M-GCM. Our results showed that the M-GCM increased the contrast between the neuronal structure and its surrounding extracellular matrix. Compared to the GCM, the M-GCM also diminished the impact of the artefacts and incomplete vasculature on the 3D image. Additionally, the 3D neuronal architecture was successfully quantified using a combination of SRμCT and M-GCM. The SRμCT was shown to be a valuable non-destructive tool for 3D visualization of the neuronal network in the broad 3D region of the spinal cord. Such a combinatorial method will, therefore, transform the presentation of Golgi staining from 2 to 3D, providing significant improvements in the 3D rendering of the neuronal network.
Collapse
Affiliation(s)
- Liyuan Jiang
- Department of Spine Surgery, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China.,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China.,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China
| | - Yong Cao
- Department of Spine Surgery, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China.,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China.,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China
| | - Xianzhen Yin
- Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, People's Republic of China
| | - Shuangfei Ni
- Department of Spine Surgery, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China.,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China.,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China
| | - Miao Li
- Department of Spine Surgery, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China.,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China.,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China
| | - Chengjun Li
- Department of Spine Surgery, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China.,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China.,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China
| | - Zixiang Luo
- Department of Spine Surgery, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China.,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China.,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China
| | - Hongbin Lu
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China. .,Department of Sports Medicine, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China. .,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China. .,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China.
| | - Jianzhong Hu
- Department of Spine Surgery, Xiangya Hospital, Central South University, Xiangya Road No. 87, Changsha, 410008, Hunan, People's Republic of China. .,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, 410008, People's Republic of China. .,Xiangya Hospital-International Chinese Musculoskeletal Research Society Sports Medicine Research Centre, Changsha, People's Republic of China. .,Hunan Engineering Research Center of Sport and Health, Changsha, People's Republic of China.
| |
Collapse
|
17
|
Kaul D, Smith CC, Stevens J, Fröhlich AS, Binder EB, Mechawar N, Schwab SG, Matosin N. Severe childhood and adulthood stress associates with neocortical layer-specific reductions of mature spines in psychiatric disorders. Neurobiol Stress 2020; 13:100270. [PMID: 33344723 PMCID: PMC7739192 DOI: 10.1016/j.ynstr.2020.100270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/04/2020] [Accepted: 11/17/2020] [Indexed: 12/22/2022] Open
Abstract
Severe stress exposure causes the loss of dendritic spines on cortical pyramidal neurons and induces psychiatric-like symptoms in rodent models. These effects are strongest following early-life stress and are most persistent on apical dendrites. However, the long-term impacts and temporal effects of stress exposure on the human brain remain poorly understood. Using a novel postmortem cohort of psychiatric cases with severe stress experienced in childhood, adulthood, or no severe stress, and matched controls, we aimed to determine the impact of stress timing on pyramidal neuron structure in the human orbitofrontal cortex (OFC). We performed Golgi Cox staining and manually measured the morphology and density of over 22,000 dendritic spines on layer-specific pyramidal neuron apical dendrites. We also quantified glucocorticoid receptor mRNA and protein as a marker of stress dysregulation. Both childhood and adulthood stress were associated with large reductions in mature mushroom spine density (up to 56% loss) in both the superficial (II/III) and deeper layers (V) of the OFC. However, childhood stress caused more substantial reductions to both total and mature mushroom spines. No difference in glucocorticoid receptor mRNA and protein were seen between groups, although both negatively correlated with total spine density within the whole cohort. These findings indicate that severe stress, especially when experienced during childhood, persistently affects the fine morphological properties of neurons in the human OFC. This may impact on cell connectivity in this brain area, and at least partly explain the social and emotional symptoms that originate in the OFC in psychiatric disorders.
Collapse
Affiliation(s)
- Dominic Kaul
- Illawarra Health and Medical Research Institute, Northfields Ave, Wollongong, 2522, Australia.,Molecular Horizons, School of Chemistry and Molecular Biosciences, University of Wollongong, Northfields Ave, Wollongong, 2522, Australia
| | - Caine C Smith
- NSW Brain Tissue Resource Centre, Discipline of Pathology, School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Julia Stevens
- NSW Brain Tissue Resource Centre, Discipline of Pathology, School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Anna S Fröhlich
- Dept. of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804, Munich, Germany.,International Max Planck Research School for Translational Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Elisabeth B Binder
- Dept. of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804, Munich, Germany
| | - Naguib Mechawar
- Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Qc, Canada, H4H 1R3
| | - Sibylle G Schwab
- Illawarra Health and Medical Research Institute, Northfields Ave, Wollongong, 2522, Australia.,Molecular Horizons, School of Chemistry and Molecular Biosciences, University of Wollongong, Northfields Ave, Wollongong, 2522, Australia
| | - Natalie Matosin
- Illawarra Health and Medical Research Institute, Northfields Ave, Wollongong, 2522, Australia.,Molecular Horizons, School of Chemistry and Molecular Biosciences, University of Wollongong, Northfields Ave, Wollongong, 2522, Australia.,Dept. of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804, Munich, Germany
| |
Collapse
|
18
|
Pchitskaya E, Bezprozvanny I. Dendritic Spines Shape Analysis-Classification or Clusterization? Perspective. Front Synaptic Neurosci 2020; 12:31. [PMID: 33117142 PMCID: PMC7561369 DOI: 10.3389/fnsyn.2020.00031] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/02/2020] [Indexed: 12/11/2022] Open
Abstract
Dendritic spines are small protrusions from the dendrite membrane, where contact with neighboring axons is formed in order to receive synaptic input. Changes in size, shape, and density of synaptic spines are associated with learning and memory, and observed after drug abuse in a variety of neurodegenerative, neurodevelopmental, and psychiatric disorders. Due to the preeminent importance of synaptic spines, there have been major efforts into developing techniques that enable visualization and analysis of dendritic spines in cultured neurons, in fixed slices and in intact brain tissue. The classification of synaptic spines into predefined morphological groups is a standard approach in neuroscience research, where spines are divided into fixed categories such as thin, mushroom, and stubby subclasses. This study examines accumulated evidence that supports the existence of dendritic spine shapes as a continuum rather than separated classes. Using new approaches and software tools we reflect on complex dendritic spine shapes, positing that understanding of their highly dynamic nature is required to perform analysis of their morphology. The study discusses and compares recently developed algorithms that rely on clusterization rather than classification, therefore enabling new levels of spine shape analysis. We reason that improved methods of analysis may help to investigate a link between dendritic spine shape and its function, facilitating future studies of learning and memory as well as studies of brain disorders.
Collapse
Affiliation(s)
- Ekaterina Pchitskaya
- Laboratory of Molecular Neurodegeneration, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Ilya Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia.,Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX, United States
| |
Collapse
|
19
|
Pannexin 1 Regulates Dendritic Protrusion Dynamics in Immature Cortical Neurons. eNeuro 2020; 7:ENEURO.0079-20.2020. [PMID: 32737184 PMCID: PMC7544189 DOI: 10.1523/eneuro.0079-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 07/16/2020] [Accepted: 07/21/2020] [Indexed: 11/21/2022] Open
Abstract
The integration of neurons into networks relies on the formation of dendritic spines. These specialized structures arise from dynamic filopodia-like dendritic protrusions. It was recently reported that cortical neurons lacking the channel protein pannexin 1 (PANX1) exhibited higher dendritic spine densities. Here, we expanded on those findings to investigate, at an earlier developmental time point (with more abundant dendritic protrusions), whether differences in the properties of dendritic protrusion dynamics could contribute to this previously discovered phenomenon. Using a fluorescent membrane tag (mCherry-CD9-10) to visualize dendritic protrusions in developing neurons [at 10 d in vitro (DIV10)], we confirmed that lack of PANX1 led to higher protrusion density, while transient transfection of Panx1 led to decreased protrusion density. To quantify the impact of PANX1 expression on protrusion formation, elimination, and motility, we used live cell imaging in DIV10 neurons (one frame every 5 s for 10 min). We discovered that at DIV10, loss of PANX1 stabilized protrusions. Notably, re-expression of PANX1 in Panx1 knock-out (KO) neurons resulted in a significant increase in protrusion motility and turnover. In summary, these new data revealed that PANX1 could regulate the development of dendritic spines, in part, by controlling dendritic protrusion dynamics.
Collapse
|
20
|
Kiffer F, Alexander T, Anderson J, Groves T, McElroy T, Wang J, Sridharan V, Bauer M, Boerma M, Allen A. Late Effects of 1H + 16O on Short-Term and Object Memory, Hippocampal Dendritic Morphology and Mutagenesis. Front Behav Neurosci 2020; 14:96. [PMID: 32670032 PMCID: PMC7332779 DOI: 10.3389/fnbeh.2020.00096] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 05/22/2020] [Indexed: 11/17/2022] Open
Abstract
The space extending beyond Earth’s magnetosphere is subject to a complex field of high-energy charged nuclei, which are capable of traversing spacecraft shielding and human tissues, inducing dense ionization events. The central nervous system is a major area of concern for astronauts who will be exposed to the deep-space radiation environment on a mission to Mars, as charged-particle radiation has been shown to elicit changes to the dendritic arbor within the hippocampus of rodents, and related cognitive-behavioral deficits. We exposed 6-month-old male mice to whole-body 1H (0.5 Gy; 150 MeV/n; 18–19 cGy/minute) and an hour later to 16O (0.1Gy; 600 MeV/n; 18–33 Gy/min) at NASA’s Space Radiation Laboratory as a galactic cosmic ray-relevant model. Animals were housed with bedding which provides cognitive enrichment. Mice were tested for cognitive behavior 9 months after exposure to elucidate late radiation effects. Radiation induced significant deficits in novel object recognition and short-term spatial memory (Y-maze). Additionally, we observed opposing morphological differences between the mature granular and pyramidal neurons throughout the hippocampus, with increased dendritic length in the dorsal dentate gyrus and reduced length and complexity in the CA1 subregion of the hippocampus. Dendritic spine analyses revealed a severe reduction in mushroom spine density throughout the hippocampus of irradiated animals. Finally, we detected no general effect of radiation on single-nucleotide polymorphisms in immediate early genes, and genes involved in inflammation but found a higher variant allele frequency in the antioxidants thioredoxin reductase 2 and 3 loci.
Collapse
Affiliation(s)
- Frederico Kiffer
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Tyler Alexander
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Julie Anderson
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Thomas Groves
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Taylor McElroy
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Jing Wang
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Vijayalakshmi Sridharan
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Michael Bauer
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Marjan Boerma
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Antiño Allen
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States.,Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| |
Collapse
|
21
|
Pneumonia-induced endothelial amyloids reduce dendritic spine density in brain neurons. Sci Rep 2020; 10:9327. [PMID: 32518286 PMCID: PMC7283224 DOI: 10.1038/s41598-020-66321-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/14/2020] [Indexed: 12/26/2022] Open
Abstract
Pseudomonas aeruginosa pneumonia elicits endothelial cell release of cytotoxic amyloids that can be recovered from the bronchoalveolar lavage and cerebrospinal fluids of critically ill patients. Introduction of these cytotoxic amyloids into the lateral ventricle impairs learning and memory in mice. However, it is unclear whether the amyloids of lung origin (1) are neurotropic, and (2) cause structural remodeling of hippocampal dendrites. Thus, we used electrophysiological studies in brain slices and structural analysis of post-mortem tissues obtained from animals exposed to endothelium-derived amyloids to assess these issues. The amyloids were administered via three different routes, by intracerebroventricular, intratracheal, and intraperitoneal injections. Synaptic long-term potentiation was abolished following intracerebroventricular amyloid injection. Fluorescence dialysis or Golgi-impregnation labeling showed reduced dendritic spine density and destabilized spines of hippocampal pyramidal neurons 4 weeks after intracerebroventricular amyloid injection. In comparison, endothelial amyloids introduced to the airway caused the most prominent dendritic spine density reduction, yet intraperitoneal injection of these amyloids did not affect spine density. Our findings indicate that infection-elicited lung endothelial amyloids are neurotropic and reduce neuronal dendritic spine density in vivo. Amyloids applied into the trachea may either be disseminated through the circulation and cross the blood-brain barrier to access the brain, initiate feed-forward amyloid transmissibility among cells of the blood-brain barrier or access the brain in other ways. Nevertheless, lung-derived amyloids suppress hippocampal signaling and cause injury to neuronal structure.
Collapse
|
22
|
Li H, McLaurin KA, Mactutus CF, Booze RM. Ballistic Labeling of Pyramidal Neurons in Brain Slices and in Primary Cell Culture. J Vis Exp 2020. [PMID: 32310238 DOI: 10.3791/60989] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
It has been reported that the size and shape of dendritic spines is related to their structural plasticity. To identify the morphological structure of pyramidal neurons and dendritic spines, a ballistic labeling technique can be utilized. In the present protocol, pyramidal neurons are labeled with DilC18(3) dye and analyzed using neuronal reconstruction software to assess neuronal morphology and dendritic spines. To investigate neuronal structure, dendritic branching analysis and Sholl analysis are performed, allowing researchers to draw inferences about dendritic branching complexity and neuronal arbor complexity, respectively. The evaluation of dendritic spines is conducted using an automatic assisted classification algorithm integral to the reconstruction software, which classifies spines into four categories (i.e., thin, mushroom, stubby, filopodia). Furthermore, an additional three parameters (i.e., length, head diameter, and volume) are also chosen to assess alterations in dendritic spine morphology. To validate the potential of wide application of the ballistic labeling technique, pyramidal neurons from in vitro cell culture were successfully labeled. Overall, the ballistic labeling method is unique and useful for visualizing neurons in different brain regions in rats, which in combination with sophisticated reconstruction software, allows researchers to elucidate the possible mechanisms underlying neurocognitive dysfunction.
Collapse
Affiliation(s)
- Hailong Li
- Program in Behavioral Neuroscience, Department of Psychology, University of South Carolina
| | - Kristen A McLaurin
- Program in Behavioral Neuroscience, Department of Psychology, University of South Carolina
| | - Charles F Mactutus
- Program in Behavioral Neuroscience, Department of Psychology, University of South Carolina
| | - Rosemarie M Booze
- Program in Behavioral Neuroscience, Department of Psychology, University of South Carolina;
| |
Collapse
|
23
|
Zhu H, Meissner LE, Byrnes C, Tuymetova G, Tifft CJ, Proia RL. The Complement Regulator Susd4 Influences Nervous-System Function and Neuronal Morphology in Mice. iScience 2020; 23:100957. [PMID: 32179479 PMCID: PMC7075988 DOI: 10.1016/j.isci.2020.100957] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 10/31/2019] [Accepted: 02/25/2020] [Indexed: 01/02/2023] Open
Abstract
The SUSD4 (Sushi domain-containing protein 4) gene encodes a complement inhibitor that is frequently deleted in 1q41q42 microdeletion syndrome, a multisystem congenital disorder that includes neurodevelopmental abnormalities. To understand SUSD4's role in the mammalian nervous system, we analyzed Susd4 knockout (KO) mice. Susd4 KO mice exhibited significant defects in motor performance and significantly higher levels of anxiety-like behaviors. Susd4 KO brain had abnormal “hairy” basket cells surrounding Purkinje neurons within the cerebellum and significantly reduced dendritic spine density in hippocampal pyramidal neurons. Neurons and oligodendrocyte lineage cells of wild-type mice were found to express Susd4 mRNA. Protein expression of the complement component C1q was increased in the brains of Susd4 KO mice. Our data indicate that SUSD4 plays an important role in neuronal functions, possibly via the complement pathway, and that SUSD4 deletion may contribute to the nervous system abnormalities in patients with 1q41q42 deletions. Susd4 is expressed in neurons and oligodendrocyte lineage cells Susd4 knockout mice have abnormal hippocampal and cerebellar neuronal morphologies Susd4 knockout mice exhibit anxiety-like behaviors and impaired motor function Susd4 knockout mice have elevated brain levels of the complement component C1q
Collapse
Affiliation(s)
- Hongling Zhu
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Laura E Meissner
- Office of the Clinical Director and Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Colleen Byrnes
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Galina Tuymetova
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Cynthia J Tifft
- Office of the Clinical Director and Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Richard L Proia
- Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
| |
Collapse
|
24
|
Gisabella B, Scammell T, Bandaru SS, Saper CB. Regulation of hippocampal dendritic spines following sleep deprivation. J Comp Neurol 2019; 528:380-388. [PMID: 31454077 DOI: 10.1002/cne.24764] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/30/2019] [Accepted: 08/22/2019] [Indexed: 01/10/2023]
Abstract
Accumulating evidence supports the role of sleep in synaptic plasticity and memory consolidation. One line of investigation, the synaptic homeostasis hypothesis, has emphasized the increase in synaptic strength during waking, and compensatory downsizing of (presumably less frequently used) synapses during sleep. Conversely, other studies have reported downsizing and loss of dendritic spines following sleep deprivation. We wanted to determine the effect of sleep deprivation on dendritic spines of hippocampal CA1 neurons using genetic methods for fluorescent labeling of dendritic spines. Male Vglut2-Cre mice were injected with an AAV-DIO-ChR2-mCherry reporter in CA1 hippocampus. Gentle handling was used to sleep deprive mice for 5 hr, from lights on (7 am) to 12 noon. Control and sleep-deprived mice were euthanized at 12 noon and processed for quantification of dendritic spines. We used confocal microscope imaging and three-dimensional (3D) analysis to quantify thin, mushroom, and stubby spines from CA1 dendrites, distinguishing between branch segments. We observed significantly greater density of spines in CA1 of sleep-deprived mice, driven primarily by greater numbers of thin spines, and significantly larger spine volume and head diameter. Branch and region-specific analysis revealed that spine volume was greater in primary dendrites of apical and basal segments, along with proximal segments on both apical and basal dendrites, and spine density was increased in secondary branches and distal segments on apical dendrites following sleep deprivation. Our 3D quantification suggests sleep contributes to region- and branch-specific synaptic downscaling in the hippocampus, supporting the theory of broad but selective synaptic downscaling during sleep.
Collapse
Affiliation(s)
- Barbara Gisabella
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.,Department of Anatomy and Neurobiological Sciences, University of Mississippi Medical Center, Jackson, Mississippi
| | - Thomas Scammell
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Sathyajit S Bandaru
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Clifford B Saper
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
25
|
Abstract
Many brain disorders exhibit altered synapse formation in development or synapse loss with age. To understand the complexities of human synapse development and degeneration, scientists now engineer neurons and brain organoids from human-induced pluripotent stem cells (hIPSC). These hIPSC-derived brain models develop both excitatory and inhibitory synapses and functional synaptic activity. In this review, we address the ability of hIPSC-derived brain models to recapitulate synapse development and insights gained into the molecular mechanisms underlying synaptic alterations in neuronal disorders. We also discuss the potential for more accurate human brain models to advance our understanding of synapse development, degeneration, and therapeutic responses.
Collapse
Affiliation(s)
- Emily S Wilson
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834
| | - Karen Newell-Litwa
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834
| |
Collapse
|
26
|
Characterization of Nanoscale Organization of F-Actin in Morphologically Distinct Dendritic Spines In Vitro Using Supervised Learning. eNeuro 2019; 6:ENEURO.0425-18.2019. [PMID: 31311803 PMCID: PMC6709208 DOI: 10.1523/eneuro.0425-18.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 05/17/2019] [Accepted: 05/22/2019] [Indexed: 12/22/2022] Open
Abstract
The cytoarchitecture of a neuron is very important in defining morphology and ultrastructure. Although there is a wealth of information on the molecular components that make and regulate these ultrastructures, there is a dearth of understanding of how these changes occur or how they affect neurons in health and disease. Recent advances in nanoscale imaging which resolve cellular structures at the scale of tens of nanometers below the limit of diffraction enable us to understand these structures in fine detail. However, automated analysis of these images is still in its infancy. Towards this goal, attempts have been made to automate the detection and analysis of the cytoskeletal organization of microtubules. To date, evaluation of the nanoscale organization of filamentous actin (F-actin) in neuronal compartments remains challenging. Here, we present an objective paradigm for analysis which adopts supervised learning of nanoscale images of F-actin network in excitatory synapses, obtained by single molecule based super-resolution light microscopy. We have used the proposed analysis to understand the heterogeneity in the organization of F-actin in dendritic spines of primary neuronal cultures from rodents. Our results were validated using ultrastructural data obtained from platinum replica electron microscopy (PREM). The automated analysis approach was used to differentiate the heterogeneity in the nanoscale organization of F-actin in primary neuronal cultures from wild-type (WT) and a transgenic mouse model of Alzheimer’s disease (APPSwe/PS1ΔE9).
Collapse
|
27
|
Sivaguru M, Khaw YM, Inoue M. A Confocal Reflection Super-Resolution Technique to Image Golgi-Cox Stained Neurons. J Microsc 2019; 275:115-130. [PMID: 31237354 DOI: 10.1111/jmi.12821] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 06/20/2019] [Accepted: 06/23/2019] [Indexed: 11/26/2022]
Abstract
Metal-based Golgi-Cox (GC) staining is an established method used to visualise neurons with great morphological detail. Although GC stained samples are imaged routinely under transmitted light microscopy, this method is unable to yield information on the three-dimensional structure of dendrites and neurons and thus help reveal the connective properties of the central nervous system. Although a few studies have attempted simultaneous visualisation of GC staining and antigen-specific fluorescent labelling under a confocal reflection technique, the resolution of both confocal reflection and fluorescence modalities used to acquire GC reflection and fluorescently stained antibody signals are still limited by the diffraction limit of light at about 220 nm. Here, we report a confocal reflection super-resolution technique (CRSR) to break this diffraction barrier, which is achieved by minimising the pinhole size from 1 airy unit (AU) to 0.1 AU. This is achieved by minimising or closing the confocal pinhole size and is possible in this reflection modality, unlike fluorescence, because it is not a photon limited technique. Utilising the lowest wavelength of light available in the system (405 nm), the CRSR technique results in ∼30% lateral and axial resolution improvement. We also show that the CRSR technique can be used in conjunction to visualise both GC and immunofluorescence targets to create precise and improved three-dimensional visualisation and analysis. In addition, using these superresolution confocal reflection data sets from GC in CRSR mode significantly reduced the data overestimation, improving the accuracy of statistical analysis of dendritic spine density and average spine dimensions. Combining the 0.1 AU setting with deconvolution routines, the signal-to-noise ratio and resolution could further be improved an additional ∼20-25%, yielding CRSR images with resolutions up to 2-fold over the diffraction limit both laterally and axially. The improved precision of both visualisation and quantification of subdiffraction limited dendritic spines using the CRSR technique may prove to be critical in investigations that concern changes in detailed neuron morphology under central nervous system disease conditions such as multiple sclerosis and Alzheimer's disease. LAY DESCRIPTION: For over a century, Golgi-Cox (GC) has been a leading staining technique in the field of neuroscience, used to visualise neurons with great morphological detail. GC stained brain or spinal cord samples are conventionally visualised under transmitted light techniques. This limits the view of Golgi-staining to a two-dimensional image. A recent report showed that Golgi staining can be visualised in three-dimensions using the reflection modality of the confocal microscope. This visualisation also allows for the simultaneous acquisition of immunofluorescence signals. However, the reported resolution of Golgi staining confocal reflection is limited by the diffraction limit of light, which is around 220 nm. Here, we report a superresolution confocal reflection technique (CRSR) that achieves superresolution by minimising the pinhole size used in confocal microscopy. The CRSR technique results in ∼30% lateral and axial resolution improvement. Adding a deconvolution step in the final processing could improve the SNR and resolution even further up to 2-fold improvement in resolution over the diffraction limit both laterally and axially. We hope that this improved visualisation will help in investigations that concern changes in detailed neuron morphology under central nervous system disease conditions such as multiple sclerosis and Alzheimer's disease.
Collapse
Affiliation(s)
- Mayandi Sivaguru
- Microscopy and Imaging Core Facility, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A.,Carl Zeiss Labs at Location Partner, Microscopy and Imaging Core Facility, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A
| | - Yee Ming Khaw
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A
| | - Makoto Inoue
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A
| |
Collapse
|
28
|
Chidambaram SB, Rathipriya AG, Bolla SR, Bhat A, Ray B, Mahalakshmi AM, Manivasagam T, Thenmozhi AJ, Essa MM, Guillemin GJ, Chandra R, Sakharkar MK. Dendritic spines: Revisiting the physiological role. Prog Neuropsychopharmacol Biol Psychiatry 2019; 92:161-193. [PMID: 30654089 DOI: 10.1016/j.pnpbp.2019.01.005] [Citation(s) in RCA: 149] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 01/04/2019] [Accepted: 01/12/2019] [Indexed: 12/11/2022]
Abstract
Dendritic spines are small, thin, specialized protrusions from neuronal dendrites, primarily localized in the excitatory synapses. Sophisticated imaging techniques revealed that dendritic spines are complex structures consisting of a dense network of cytoskeletal, transmembrane and scaffolding molecules, and numerous surface receptors. Molecular signaling pathways, mainly Rho and Ras family small GTPases pathways that converge on actin cytoskeleton, regulate the spine morphology and dynamics bi-directionally during synaptic activity. During synaptic plasticity the number and shapes of dendritic spines undergo radical reorganizations. Long-term potentiation (LTP) induction promote spine head enlargement and the formation and stabilization of new spines. Long-term depression (LTD) results in their shrinkage and retraction. Reports indicate increased spine density in the pyramidal neurons of autism and Fragile X syndrome patients and reduced density in the temporal gyrus loci of schizophrenic patients. Post-mortem reports of Alzheimer's brains showed reduced spine number in the hippocampus and cortex. This review highlights the spine morphogenesis process, the activity-dependent structural plasticity and mechanisms by which synaptic activity sculpts the dendritic spines, the structural and functional changes in spines during learning and memory using LTP and LTD processes. It also discusses on spine status in neurodegenerative diseases and the impact of nootropics and neuroprotective agents on the functional restoration of dendritic spines.
Collapse
Affiliation(s)
- Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India.
| | - A G Rathipriya
- Food and Brain Research Foundation, Chennai, Tamil Nadu, India
| | - Srinivasa Rao Bolla
- Department of Anatomy, College of Medicine, Imam Abdulrahman Bin Faisal University, Damam, Saudi Arabia
| | - Abid Bhat
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Bipul Ray
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Arehally Marappa Mahalakshmi
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Thamilarasan Manivasagam
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Arokiasamy Justin Thenmozhi
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Musthafa Mohamed Essa
- Department of Food Science and Nutrition, CAMS, Sultan Qaboos University, Muscat, Oman
| | - Gilles J Guillemin
- Neuropharmacology Group, Faculty of Medicine and Health Sciences, Deb Bailey MND Research Laboratory, Macquarie University, Sydney, NSW 2109, Australia
| | - Ramesh Chandra
- Department of Chemistry, Ambedkar Centre for BioMedical Research, Delhi University, Delhi 110007, India
| | - Meena Kishore Sakharkar
- College of Pharmacy and Nutrition, University of Saskatchewan, 107, Wiggins Road, Saskatoon, SK S7N 5C9, Canada.
| |
Collapse
|
29
|
Ginsenoside Rg1 Prevents Chemotherapy-Induced Cognitive Impairment: Associations with Microglia-Mediated Cytokines, Neuroinflammation, and Neuroplasticity. Mol Neurobiol 2019; 56:5626-5642. [DOI: 10.1007/s12035-019-1474-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 01/10/2019] [Indexed: 12/26/2022]
|
30
|
McLaurin KA, Cook AK, Li H, League AF, Mactutus CF, Booze RM. Synaptic Connectivity in Medium Spiny Neurons of the Nucleus Accumbens: A Sex-Dependent Mechanism Underlying Apathy in the HIV-1 Transgenic Rat. Front Behav Neurosci 2018; 12:285. [PMID: 30524255 PMCID: PMC6262032 DOI: 10.3389/fnbeh.2018.00285] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/05/2018] [Indexed: 01/03/2023] Open
Abstract
Frontal-subcortical circuit dysfunction is commonly associated with apathy, a neuropsychiatric sequelae of human immunodeficiency virus type-1 (HIV-1). Behavioral and neurochemical indices of apathy in the nucleus accumbens (NAc), a key brain region involved in frontal-subcortical circuitry, are influenced by the factor of biological sex. Despite evidence of sex differences in HIV-1, the effect of biological sex on medium spiny neurons (MSNs), which are central integrators of frontal-subcortical input, has not been systematically evaluated. In the present study, a DiOlistic labeling technique was used to investigate the role of long-term HIV-1 viral protein exposure, the factor of biological sex, and their possible interaction, on synaptic dysfunction in MSNs of the NAc in the HIV-1 transgenic (Tg) rat. HIV-1 Tg rats, independent of biological sex, displayed profound alterations in synaptic connectivity, evidenced by a prominent shift in the distribution of dendritic spines. Female HIV-1 Tg rats, but not male HIV-1 Tg rats, exhibited alterations in dendritic branching and neuronal arbor complexity relative to control animals, supporting an alteration in glutamate neurotransmission. Morphologically, HIV-1 Tg male, but not female HIV-1 Tg rats, displayed a population shift towards decreased dendritic spine volume, suggesting decreased synaptic area, relative to control animals. Synaptic dysfunction accurately identified presence of the HIV-1 transgene, dependent upon biological sex, with at least 80% accuracy (i.e., Male: 80%; Female: 90%). Collectively, these results support a primary alteration in circuit connectivity, the mechanism of which is dependent upon biological sex. Understanding the effect of biological sex on the underlying neural mechanism for HIV-1 associated apathy is vital for the development of sex-based therapeutics and cure strategies.
Collapse
Affiliation(s)
- Kristen A McLaurin
- Department of Psychology, Program in Behavioral Neuroscience, University of South Carolina, Columbia, SC, United States
| | - Anna K Cook
- Department of Psychology, Program in Behavioral Neuroscience, University of South Carolina, Columbia, SC, United States
| | - Hailong Li
- Department of Psychology, Program in Behavioral Neuroscience, University of South Carolina, Columbia, SC, United States
| | - Alexis F League
- Department of Psychology, Program in Behavioral Neuroscience, University of South Carolina, Columbia, SC, United States
| | - Charles F Mactutus
- Department of Psychology, Program in Behavioral Neuroscience, University of South Carolina, Columbia, SC, United States
| | - Rosemarie M Booze
- Department of Psychology, Program in Behavioral Neuroscience, University of South Carolina, Columbia, SC, United States
| |
Collapse
|
31
|
Shi DD, Huang YH, Lai CSW, Dong CM, Ho LC, Wu EX, Li Q, Wang XM, Chung SK, Sham PC, Zhang ZJ. Chemotherapy-Induced Cognitive Impairment Is Associated with Cytokine Dysregulation and Disruptions in Neuroplasticity. Mol Neurobiol 2018; 56:2234-2243. [PMID: 30008071 DOI: 10.1007/s12035-018-1224-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 07/03/2018] [Indexed: 12/20/2022]
Abstract
Chemotherapy-induced cognitive impairment, often referred to as "chemobrain," is a common side effect. In this study, mice received three intraperitoneal injections of a combination of docetaxel, adriamycin, and cyclophosphamide (DAC) at 2-day intervals. A water maze test was used to examine cognitive performance, and manganese-enhanced magnetic resonance imaging (MEMRI) was used to examine hippocampal neuronal activity. The whole brain, prefrontal cortex, hippocampus, and blood samples were then collected for cytokine measurement. The DAC-treated mice displayed a significantly shorter duration spent in and fewer entries into the target quadrant of the water maze than the control mice and a pronounced decrease in MEMRI signal intensity in the hippocampal subregions. In a separate experiment using in vivo transcranial two-photon imaging, DAC markedly eliminated dendritic spines without changing the rate of spine formation, leading to a striking loss of spines in the medial prefrontal cortex. DAC treatment resulted in significant elevations in the levels of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) and in significant decreases in the levels of the anti-inflammatory cytokines IL-4 and IL-10 in most of the sera and brain tissues examined. The IL-6 and TNF-α levels of several sera and brain tissues showed strong inverse correlations with the duration and number of entries in the target quadrant of the water maze and with the hippocampal MEMRI signal intensity, but also showed striking positive correlations with spine elimination and loss. These results indicate that chemobrain is associated with cytokine dysregulation and disrupted neuroplasticity of the brain.
Collapse
Affiliation(s)
- Dong-Dong Shi
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Yu-Hua Huang
- School of Biomedical Sciences, State Key Laboratory of Pharmaceutical Biotechnology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Cora Sau Wan Lai
- School of Biomedical Sciences, State Key Laboratory of Pharmaceutical Biotechnology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Celia M Dong
- Laboratory of Biomedical Imaging and Signal Processing, Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
| | - Leon C Ho
- Laboratory of Biomedical Imaging and Signal Processing, Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
| | - Qi Li
- Department of Psychiatry, State Key Laboratory of Cognitive and Brain Sciences, HKU-SIRI, The University of Hong Kong, Hong Kong, China
| | - Xiao-Min Wang
- Department of Anesthesiology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Sookja Kim Chung
- School of Biomedical Sciences, State Key Laboratory of Pharmaceutical Biotechnology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Pak Chung Sham
- Department of Psychiatry, State Key Laboratory of Cognitive and Brain Sciences, Genome Research Centre, The University of Hong Kong, Hong Kong, SAR, China
| | - Zhang-Jin Zhang
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China.
| |
Collapse
|
32
|
Garrett L, Ung M, Heermann T, Niedermeier KM, Hölter S. Analysis of Neuropsychiatric Disease‐Related Functional Neuroanatomical Markers in Mice. ACTA ACUST UNITED AC 2018; 8:79-128. [DOI: 10.1002/cpmo.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Lillian Garrett
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health Neuherberg Germany
- German Mouse Clinic, Helmholtz Zentrum München; German Research Centre for Environmental Health Neuherberg Germany
| | - Marie‐Claire Ung
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health Neuherberg Germany
| | - Tamara Heermann
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health Neuherberg Germany
| | - Kristina M. Niedermeier
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health Neuherberg Germany
| | - Sabine Hölter
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Centre for Environmental Health Neuherberg Germany
- German Mouse Clinic, Helmholtz Zentrum München; German Research Centre for Environmental Health Neuherberg Germany
| |
Collapse
|
33
|
Quantitative 3-D morphometric analysis of individual dendritic spines. Sci Rep 2018; 8:3545. [PMID: 29476060 PMCID: PMC5825014 DOI: 10.1038/s41598-018-21753-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 02/05/2018] [Indexed: 01/09/2023] Open
Abstract
The observation and analysis of dendritic spines morphological changes poses a major challenge in neuroscience studies. The alterations of their density and/or morphology are indicators of the cellular processes involved in neural plasticity underlying learning and memory, and are symptomatic in neuropsychiatric disorders. Despite ongoing intense investigations in imaging approaches, the relationship between changes in spine morphology and synaptic function is still unknown. The existing quantitative analyses are difficult to perform and require extensive user intervention. Here, we propose a new method for (1) the three-dimensional (3-D) segmentation of dendritic spines using a multi-scale opening approach and (2) define 3-D morphological attributes of individual spines for the effective assessment of their structural plasticity. The method was validated using confocal light microscopy images of dendritic spines from dissociated hippocampal cultures and brain slices (1) to evaluate accuracy relative to manually labeled ground-truth annotations and relative to the state-of-the-art Imaris tool, (2) to analyze reproducibility of user-independence of the segmentation method, and (3) to quantitatively analyze morphological changes in individual spines before and after chemically induced long-term potentiation. The method was monitored and used to precisely describe the morphology of individual spines in real-time using consecutive images of the same dendritic fragment.
Collapse
|
34
|
Kassem MS, Fok SY, Smith KL, Kuligowski M, Balleine BW. A novel, modernized Golgi-Cox stain optimized for CLARITY cleared tissue. J Neurosci Methods 2018; 294:102-110. [DOI: 10.1016/j.jneumeth.2017.11.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 11/14/2017] [Accepted: 11/14/2017] [Indexed: 10/18/2022]
|
35
|
Kiffer F, Carr H, Groves T, Anderson JE, Alexander T, Wang J, Seawright JW, Sridharan V, Carter G, Boerma M, Allen AR. Effects of 1H + 16O Charged Particle Irradiation on Short-Term Memory and Hippocampal Physiology in a Murine Model. Radiat Res 2017; 189:53-63. [PMID: 29136391 DOI: 10.1667/rr14843.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Radiation from galactic cosmic rays (GCR) poses a significant health risk for deep-space flight crews. GCR are unique in their extremely high-energy particles. With current spacecraft shielding technology, some of the predominant particles astronauts would be exposed to are 1H + 16O. Radiation has been shown to cause cognitive deficits in mice. The hippocampus plays a key role in memory and cognitive tasks; it receives information from the cortex, undergoes dendritic-dependent processing and then relays information back to the cortex. In this study, we investigated the effects of combined 1H + 16O irradiation on cognition and dendritic structures in the hippocampus of adult male mice three months postirradiation. Six-month-old male C57BL/6 mice were irradiated first with 1H (0.5 Gy, 150 MeV/n) and 1 h later with 16O (0.1 Gy, 600 MeV/n) at the NASA Space Radiation Laboratory (Upton, NY). Three months after irradiation, animals were tested for hippocampus-dependent cognitive performance using the Y-maze. Upon sacrifice, molecular and morphological assessments were performed on hippocampal tissues. During Y-maze testing, the irradiated mice failed to distinguish the novel arm, spending approximately the same amount of time in all three arms during the retention trial relative to sham-treated controls. Irradiated animals also showed changes in expression of glutamate receptor subunits and synaptic density-associated proteins. 1H + 16O radiation compromised dendritic morphology in the cornu ammonis 1 and dentate gyrus within the hippocampus. These data indicate cognitive injuries due to 1H + 16O at three months postirradiation.
Collapse
Affiliation(s)
- Frederico Kiffer
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | - Hannah Carr
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | - Thomas Groves
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences.,c Center for Translational Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Julie E Anderson
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | - Tyler Alexander
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | - Jing Wang
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | - John W Seawright
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | | | - Gwendolyn Carter
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | - Marjan Boerma
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences
| | - Antiño R Allen
- a Division of Radiation Health.,b Department of Pharmaceutical Sciences.,c Center for Translational Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| |
Collapse
|
36
|
Reberger R, Dall'Oglio A, Jung CR, Rasia-Filho AA. Structure and diversity of human dendritic spines evidenced by a new three-dimensional reconstruction procedure for Golgi staining and light microscopy. J Neurosci Methods 2017; 293:27-36. [PMID: 28887132 DOI: 10.1016/j.jneumeth.2017.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/30/2017] [Accepted: 09/03/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Different approaches aim to unravel detailed morphological features of neural cells. Dendritic spines are multifunctional units that reflect cellular connectivity, synaptic strength and plasticity. NEW METHOD A novel three-dimensional (3D) reconstruction procedure is introduced for visualization of dendritic spines from human postmortem brain tissue using brightfield microscopy. The segmentation model was based on thresholding the intensity values of the dendritic spine image along 'z' stacks. We used median filtering and removed false positives. Fine adjustments during image processing confirmed that the reconstructed image of the spines corresponded to the actual original data. RESULTS Examples are shown for the cortical amygdaloid nucleus and the CA3 hippocampal area. Structure of spine heads and necks was evaluated at different angles. Our 3D reconstruction images display dendritic spines either isolated or in clusters, in a continuum of shapes and sizes, from simple to more elaborated forms, including the presence of spinule and complex 'thorny excrescences'. COMPARISON WITH EXISTING METHODS The procedure has the advantages already described for the adapted "single-section" Golgi method, since it provides suitable results using human brains fixed in formalin for long time, is relatively easy, requires minimal equipment, and uses an algorithm for 3D reconstruction that provides high quality images and more precise morphological data. CONCLUSION The procedure described here allows the reliable visualization and study of human dendritic spines with broad applications for normal controls and pathological studies.
Collapse
Affiliation(s)
- Roman Reberger
- Friedrich Alexander Universität Erlangen-Nürnberg, Medical Engineering Program, Erlangen, Germany; Federal University of Rio Grande do Sul, Institute of Informatics, Porto Alegre, Brazil
| | - Aline Dall'Oglio
- Federal University of Health Sciences, Department of Basic Sciences/Physiology, Porto Alegre, Brazil
| | - Claudio R Jung
- Federal University of Rio Grande do Sul, Institute of Informatics, Porto Alegre, Brazil
| | - Alberto A Rasia-Filho
- Federal University of Health Sciences, Department of Basic Sciences/Physiology, Porto Alegre, Brazil; Federal University of Rio Grande do Sul, Neuroscience Program, Porto Alegre, Brazil.
| |
Collapse
|
37
|
Xu B, Sun A, He Y, Qian F, Liu L, Chen Y, Luo H. Running-induced memory enhancement correlates with the preservation of thin spines in the hippocampal area CA1 of old C57BL/6 mice. Neurobiol Aging 2017; 52:106-116. [DOI: 10.1016/j.neurobiolaging.2017.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/31/2016] [Accepted: 01/02/2017] [Indexed: 01/01/2023]
|
38
|
Gipson CD, Olive MF. Structural and functional plasticity of dendritic spines - root or result of behavior? GENES BRAIN AND BEHAVIOR 2016; 16:101-117. [PMID: 27561549 DOI: 10.1111/gbb.12324] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 08/19/2016] [Accepted: 08/24/2016] [Indexed: 02/06/2023]
Abstract
Dendritic spines are multifunctional integrative units of the nervous system and are highly diverse and dynamic in nature. Both internal and external stimuli influence dendritic spine density and morphology on the order of minutes. It is clear that the structural plasticity of dendritic spines is related to changes in synaptic efficacy, learning and memory and other cognitive processes. However, it is currently unclear whether structural changes in dendritic spines are primary instigators of changes in specific behaviors, a consequence of behavioral changes, or both. In this review, we first examine the basic structure and function of dendritic spines in the brain, as well as laboratory methods to characterize and quantify morphological changes in dendritic spines. We then discuss the existing literature on the temporal and functional relationship between changes in dendritic spines in specific brain regions and changes in specific behaviors mediated by those regions. Although technological advancements have allowed us to better understand the functional relevance of structural changes in dendritic spines that are influenced by environmental stimuli, the role of spine dynamics as an underlying driver or consequence of behavior still remains elusive. We conclude that while it is likely that structural changes in dendritic spines are both instigators and results of behavioral changes, improved research tools and methods are needed to experimentally and directly manipulate spine dynamics in order to more empirically delineate the relationship between spine structure and behavior.
Collapse
Affiliation(s)
- C D Gipson
- Department of Psychology, Arizona State University, Tempe, AZ, USA
| | - M F Olive
- Department of Psychology, Arizona State University, Tempe, AZ, USA
| |
Collapse
|
39
|
Beta-hydroxy-beta-methylbutyrate ameliorates aging effects in the dendritic tree of pyramidal neurons in the medial prefrontal cortex of both male and female rats. Neurobiol Aging 2016; 40:78-85. [PMID: 26973106 DOI: 10.1016/j.neurobiolaging.2016.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 11/22/2022]
Abstract
Beta-hydroxy-beta-methylbutyrate (HMB), a supplement commonly used to maintain muscle in elderly and clinical populations, has been unexplored in the aging brain. In both healthy aging humans and rat models, there are cognitive deficits associated with age-related dendritic shrinkage within the prefrontal cortex. The present study explores the effects of relatively short- and long-term (7 and 31 weeks) oral HMB supplementation starting at 12 months of age in male and female rats on the dendritic tree of layer 5 pyramidal neurons in the medial prefrontal cortex. Since female rats continue to secrete ovarian hormones after reaching reproductive senescence, middle-aged female rats were ovariectomized to model humans. As expected, there were fewer spines and a retraction of dendritic material in the apical and basilar trees in old age controls of both sexes compared with their middle-aged counterparts. However, these losses did not occur in the HMB-treated rats in either dendrites or the total number of dendritic spines. Thus, HMB forestalled the effects of aging on the dendritic tree of this population of neurons.
Collapse
|
40
|
Hu F, Ge MM, Chen WH. Effects of lead exposure on dendrite and spine development in hippocampal dentate gyrus areas of rats. Synapse 2016; 70:87-97. [DOI: 10.1002/syn.21873] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 10/27/2015] [Accepted: 11/02/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Fan Hu
- School of Biotechnology and Food Engineering; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Meng-Meng Ge
- School of Biotechnology and Food Engineering; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Wei-Heng Chen
- School of Life Sciences; University of Science and Technology of China; Hefei Anhui 230027 People's Republic of China
| |
Collapse
|
41
|
Dendritic Spine Shape Analysis: A Clustering Perspective. LECTURE NOTES IN COMPUTER SCIENCE 2016. [DOI: 10.1007/978-3-319-46604-0_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
42
|
Peng H, Zhou J, Zhou Z, Bria A, Li Y, Kleissas DM, Drenkow NG, Long B, Liu X, Chen H. Bioimage Informatics for Big Data. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2016; 219:263-72. [PMID: 27207370 DOI: 10.1007/978-3-319-28549-8_10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Bioimage informatics is a field wherein high-throughput image informatics methods are used to solve challenging scientific problems related to biology and medicine. When the image datasets become larger and more complicated, many conventional image analysis approaches are no longer applicable. Here, we discuss two critical challenges of large-scale bioimage informatics applications, namely, data accessibility and adaptive data analysis. We highlight case studies to show that these challenges can be tackled based on distributed image computing as well as machine learning of image examples in a multidimensional environment.
Collapse
Affiliation(s)
- Hanchuan Peng
- Allen Institute for Brain Science, Seattle, WA, USA.
| | - Jie Zhou
- Department of Computer Science, Northern Illinois University, Dekalb, IL, USA
| | - Zhi Zhou
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Alessandro Bria
- Department of Engineering, University Campus Bio-Medico of Rome, Rome, Italy.,Department of Electrical and Information Engineering, University of Cassino and L.M., Cassino, Italy
| | - Yujie Li
- Allen Institute for Brain Science, Seattle, WA, USA.,Department of Computer Science, University of Georgia, Athens, GA, USA
| | | | - Nathan G Drenkow
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Brian Long
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Xiaoxiao Liu
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Hanbo Chen
- Allen Institute for Brain Science, Seattle, WA, USA.,Department of Computer Science, University of Georgia, Athens, GA, USA
| |
Collapse
|
43
|
Jürgens T, Jafari M, Kreutzfeldt M, Bahn E, Brück W, Kerschensteiner M, Merkler D. Reconstruction of single cortical projection neurons reveals primary spine loss in multiple sclerosis. Brain 2015; 139:39-46. [DOI: 10.1093/brain/awv353] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 10/16/2015] [Indexed: 11/13/2022] Open
|
44
|
Dall'Oglio A, Dutra ACL, Moreira JE, Rasia-Filho AA. The human medial amygdala: structure, diversity, and complexity of dendritic spines. J Anat 2015. [PMID: 26218827 DOI: 10.1111/joa.12358] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The medial nucleus of the amygdala (Me) is a component of the neural circuit for the interpretation of multimodal sensory stimuli and the elaboration of emotions and social behaviors in primates. We studied the presence, distribution, diverse shape, and connectivity of dendritic spines in the human Me of adult postmortem men. Data were obtained from the five types of multipolar neurons found in the Me using an adapted Golgi method and light microscopy, the carbocyanine DiI fluorescent dye and confocal microscopy, and transmission electron microscopy. Three-dimensional reconstruction of spines showed a continuum of shapes and sizes, with the spines either lying isolated or forming clusters. These dendritic spines were classified as stubby/wide, thin, mushroom-like, ramified or with an atypical morphology including intermediate shapes, double spines, and thorny excrescences. Pleomorphic spines were found from proximal to distal dendritic branches suggesting potential differences for synaptic processing, strength, and plasticity in the Me neurons. Furthermore, the human Me has large and thin spines with a gemmule appearance, spinules, and filopodium. The ultrastructural data showed dendritic spines forming monosynaptic or multisynaptic contacts at the spine head and neck, and with asymmetric or symmetric characteristics. Additional findings included en passant, reciprocal, and serial synapses in the Me. Complex long-necked thin spines were observed in this subcortical area. These new data reveal the diversity of the dendritic spines in the human Me likely involved with the integration and processing of local synaptic inputs and with functional implications in physiological and various neuropathological conditions.
Collapse
Affiliation(s)
- Aline Dall'Oglio
- Department of Basic Sciences/Physiology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, Brazil
| | - Ana Carolina L Dutra
- Department of Basic Sciences/Physiology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, Brazil
| | - Jorge E Moreira
- Laboratory of Synaptic Structure, Departments of Pathology and Forensic Medicine and Neuroscience and Behavior, Ribeirão Preto School of Medicine, University of São Paulo (FMRP-USP), Ribeirão Preto, Brazil
| | - Alberto A Rasia-Filho
- Department of Basic Sciences/Physiology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, Brazil
| |
Collapse
|
45
|
Maiti P, Manna J, McDonald MP. Merging advanced technologies with classical methods to uncover dendritic spine dynamics: A hot spot of synaptic plasticity. Neurosci Res 2015; 96:1-13. [DOI: 10.1016/j.neures.2015.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 02/17/2015] [Accepted: 02/19/2015] [Indexed: 01/08/2023]
|
46
|
Ren ZX, Yu HB, Li JS, Shen JL, Du WS. Suitable parameter choice on quantitative morphology of A549 cell in epithelial-mesenchymal transition. Biosci Rep 2015; 35:e00202. [PMID: 26182364 PMCID: PMC4613694 DOI: 10.1042/bsr20150070] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/07/2015] [Accepted: 04/20/2015] [Indexed: 01/28/2023] Open
Abstract
Evaluation of morphological changes in cells is an integral part of study on epithelial to mesenchymal transition (EMT), however, only a few papers reported the changes in quantitative parameters and no article compared different parameters for demanding better parameters. In the study, the purpose was to investigate suitable parameters for quantitative evaluation of EMT morphological changes. A549 human lung adenocarcinoma cell line was selected for the study. Some cells were stimulated by transforming growth factor-β1 (TGF-β1) for EMT, and other cells were as control without TGF-β1 stimulation. Subsequently, cells were placed in phase contrast microscope and three arbitrary fields were captured and saved with a personal computer. Using the tools of Photoshop software, some cells in an image were selected, segmented out and exchanged into unique hue, and other part in the image was shifted into another unique hue. The cells were calculated with 29 morphological parameters by Image Pro Plus software. A parameter between cells with or without TGF-β1 stimulation was compared statistically and nine parameters were significantly different between them. Receiver operating characteristic curve (ROC curve) of a parameter was described with SPSS software and F-test was used to compare two areas under the curves (AUCs) in Excel. Among them, roundness and radius ratio were the most AUCs and were significant higher than the other parameters. The results provided a new method with quantitative assessment of cell morphology during EMT, and found out two parameters, roundness and radius ratio, as suitable for quantification.
Collapse
Affiliation(s)
- Zhou-Xin Ren
- Institute of Gerontology, Henan University of Traditional Chinese Medicine, Longzihu University Park, Zhengzhou, Henan 450046, China
| | - Hai-Bin Yu
- First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou, Henan 450000, China
| | - Jian-Sheng Li
- Institute of Gerontology, Henan University of Traditional Chinese Medicine, Longzihu University Park, Zhengzhou, Henan 450046, China
| | - Jun-Ling Shen
- First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou, Henan 450000, China
| | - Wen-Sen Du
- Affiliated Hospital of Henan Academy of Traditional Chinese Medicine, Zhengzhou, Henan 450004, China
| |
Collapse
|
47
|
Fieblinger T, Cenci MA. Zooming in on the small: the plasticity of striatal dendritic spines in L-DOPA-induced dyskinesia. Mov Disord 2015; 30:484-93. [PMID: 25759263 DOI: 10.1002/mds.26139] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 11/07/2014] [Accepted: 12/08/2014] [Indexed: 12/21/2022] Open
Abstract
The spiny dendrites of striatal projection neurons integrate synaptic inputs of different origins to regulate movement. It has long been known that these dendrites lose spines and display atrophic features in Parkinson's disease (PD), but the significance of these morphological changes has remained unknown. Some recent studies reveal a remarkable structural plasticity of striatal spines in parkinsonian rodents treated with L-3,4-dihydroxyphenylalanine (L-DOPA), and they demonstrate an association between this plasticity and the development of dyskinesia. These studies used different approaches and animal models, which possibly explains why they emphasize different plastic changes as being most closely linked to dyskinesia (such as a growth of new spines in neurons of the indirect pathway, or a loss of spines in neurons of the direct pathway, or the appearance of spines with aberrant synaptic features). Clearly, further investigations are required to reconcile these intriguing findings and integrate them in a coherent pathophysiological model. Nevertheless, these studies may mark the beginning of a new era for dyskinesia research. In addition to addressing neurochemical and molecular events that trigger involuntary movements, there is a need to better understand the long-lasting structural reorganization of cells and circuits that maintain the brain in a "dyskinesia-prone" state. This may lead to the identification of new efficacious approaches to prevent the complications of dopaminergic therapies in PD.
Collapse
Affiliation(s)
- Tim Fieblinger
- Basal Ganglia Pathophysiology Unit, Dept. Exp. Medical Science, Lund University, BMC F11, 221 84 Lund, Sweden
| | | |
Collapse
|
48
|
Mancuso JJ, Cheng J, Yin Z, Gilliam JC, Xia X, Li X, Wong STC. Integration of multiscale dendritic spine structure and function data into systems biology models. Front Neuroanat 2014; 8:130. [PMID: 25429262 PMCID: PMC4228840 DOI: 10.3389/fnana.2014.00130] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 10/22/2014] [Indexed: 12/27/2022] Open
Abstract
Comprising 1011 neurons with 1014 synaptic connections the human brain is the ultimate systems biology puzzle. An increasing body of evidence highlights the observation that changes in brain function, both normal and pathological, consistently correlate with dynamic changes in neuronal anatomy. Anatomical changes occur on a full range of scales from the trafficking of individual proteins, to alterations in synaptic morphology both individually and on a systems level, to reductions in long distance connectivity and brain volume. The major sites of contact for synapsing neurons are dendritic spines, which provide an excellent metric for the number and strength of signaling connections between elements of functional neuronal circuits. A comprehensive model of anatomical changes and their functional consequences would be a holy grail for the field of systems neuroscience but its realization appears far on the horizon. Various imaging technologies have advanced to allow for multi-scale visualization of brain plasticity and pathology, but computational analysis of the big data sets involved forms the bottleneck toward the creation of multiscale models of brain structure and function. While a full accounting of techniques and progress toward a comprehensive model of brain anatomy and function is beyond the scope of this or any other single paper, this review serves to highlight the opportunities for analysis of neuronal spine anatomy and function provided by new imaging technologies and the high-throughput application of older technologies while surveying the strengths and weaknesses of currently available computational analytical tools and room for future improvement.
Collapse
Affiliation(s)
- James J Mancuso
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Jie Cheng
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Zheng Yin
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Jared C Gilliam
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Xiaofeng Xia
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Xuping Li
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Stephen T C Wong
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| |
Collapse
|
49
|
Fumagalli S, Ortolano F, De Simoni MG. A close look at brain dynamics: Cells and vessels seen by in vivo two-photon microscopy. Prog Neurobiol 2014; 121:36-54. [DOI: 10.1016/j.pneurobio.2014.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 06/17/2014] [Accepted: 06/29/2014] [Indexed: 01/11/2023]
|
50
|
Roscoe RF, Mactutus CF, Booze RM. HIV-1 transgenic female rat: synaptodendritic alterations of medium spiny neurons in the nucleus accumbens. J Neuroimmune Pharmacol 2014; 9:642-53. [PMID: 25037595 DOI: 10.1007/s11481-014-9555-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 07/08/2014] [Indexed: 12/31/2022]
Abstract
HIV-1 associated neurocognitive deficits are increasing in prevalence, although the neuronal basis for these deficits is unclear. HIV-1 Tg rats constitutively express 7 of 9 HIV-associated proteins, and may be useful for studying the neuropathological substrates of HIV-1 associated neurocognitive disorders (HAND). In this study, adult female HIV-1 Tg rats and F344 control rats had similar growth rates, estrous cyclicity and startle reflex inhibition to a visual prepulse stimulus. Medium spiny neurons (MSNs) in the nucleus accumbens (NAcc) were ballistically-labeled utilizing the indocarbocyanine dye DiI. The branching complexity of MSNs in the NAcc was significantly decreased in HIV-1 Tg rats, relative to controls; moreover, the shorter length and decreased volume of dendritic spines, but unchanged head diameter, in HIV-1 Tg rats suggested a reduction of longer spines and an increase in shorter, less projected spines, indicating a population shift to a more immature spine phenotype. Collectively, these results from HIV-1 Tg female rats indicated significant synaptodendritic alterations of MSNs in the NAcc occur as a consequence of chronic, low-level, exposure to HIV-1 associated proteins.
Collapse
Affiliation(s)
- Robert F Roscoe
- Laboratory of Behavioral Neuroscience, Department of Psychology, University of South Carolina, 29208, Columbia, SC, USA
| | | | | |
Collapse
|