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Prvulovic M, Sokanovic S, Simeunovic V, Vukojevic A, Jovic M, Todorovic S, Mladenovic A. The complex relationship between late-onset caloric restriction and synaptic plasticity in aged Wistar rats. IUBMB Life 2024. [PMID: 38390757 DOI: 10.1002/iub.2812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/15/2024] [Indexed: 02/24/2024]
Abstract
Age-related reduction in spine density, synaptic marker expression, and synaptic efficiency are frequently reported. These changes provide the cellular and molecular basis for the cognitive decline characteristic for old age. Nevertheless, there are several approaches that have the potential to ameliorate these processes and improve cognition, caloric restriction being one of the most promising and widely studied. While lifelong caloric restriction is known for its numerous beneficial effects, including improved cognitive abilities and increased expression of proteins essential for synaptic structure and function, the effects of late-onset and/or short-term CR on synaptic plasticity have yet to be investigated. We have previously documented that the effects of CR are strongly dependent on whether CR is initiated in young or old subjects. With this in mind, we conducted a long-term study in aging Wistar rats to examine changes in the expression of several key synaptic markers under the regimen of CR started at different time points in life. We found a significant increase in the expression of both presynaptic and postsynaptic markers. However, taking into account previously reported changes in the behavior detected in these animals, we consider that this increase cannot represent beneficial effect of CR.
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Affiliation(s)
- Milica Prvulovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Srdjan Sokanovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Valentina Simeunovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Andjela Vukojevic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Milena Jovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Smilja Todorovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Aleksandra Mladenovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
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2
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Morris M, Coste GI, Redding-Ochoa J, Guo H, Graves AR, Troncoso JC, Huganir RL. Hippocampal synaptic alterations associated with tau pathology in primary age-related tauopathy. J Neuropathol Exp Neurol 2023; 82:836-844. [PMID: 37595576 PMCID: PMC10516464 DOI: 10.1093/jnen/nlad064] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2023] Open
Abstract
Primary age-related tauopathy (PART) is characterized by aggregation of tau in the mesial temporal lobe in older individuals. High pathologic tau stage (Braak stage) or a high burden of hippocampal tau pathology has been associated with cognitive impairment in PART. However, the potential underlying mechanisms are not well understood. Cognitive impairment in many neurodegenerative diseases correlates with synaptic loss, raising the question of whether synaptic loss also occurs in PART. To address this, we investigated synaptic changes associated with tau Braak stage and high tau pathology burden in PART using synaptophysin and phospho-tau immunofluorescence. We compared 12 cases of definite PART with 6 controls and 6 Alzheimer disease cases. In this study, the hippocampal CA2 region showed loss of synaptophysin puncta and intensity in cases of PART with either a high stage (Braak IV) or a high burden of neuritic tau pathology. There was also loss of synaptophysin intensity in CA3 associated with a high stage or high burden of tau pathology. Loss of synaptophysin was present in Alzheimer disease, but the pattern appeared distinct. These novel findings suggest the presence of synaptic loss associated with either a high hippocampal tau burden or a Braak stage IV in PART.
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Affiliation(s)
- Meaghan Morris
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Gabrielle I Coste
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Javier Redding-Ochoa
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Haidan Guo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Austin R Graves
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Engineering, Baltimore, Maryland, USA
| | - Juan C Troncoso
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Richard L Huganir
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, Maryland, USA
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3
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Morris M, Coste GI, Redding-Ochoa J, Guo H, Graves AR, Troncoso JC, Huganir RL. Hippocampal Synaptic Alterations Associated with Tau Pathology in Primary Age-Related Tauopathy. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.02.22.23286323. [PMID: 36865237 PMCID: PMC9980270 DOI: 10.1101/2023.02.22.23286323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Primary Age-Related Tauopathy (PART) is characterized by the aggregation of tau in the mesial temporal lobe in older individuals. High pathologic tau stage (Braak stage) or a high burden of hippocampal tau pathology have been associated with cognitive impairment in PART. However, the underlying mechanisms of cognitive impairment in PART are not well understood. Cognitive impairment in many neurodegenerative diseases correlates with synaptic loss, raising the question of whether synaptic loss occurs in PART. To address this, we investigated synaptic changes associated with tau Braak stage and a high tau pathology burden in PART using synaptophysin and phospho-tau immunofluorescence. We compared twelve cases of definite PART with six young controls and six Alzheimer's disease cases. In this study, we identified loss of synaptophysin puncta and intensity in the CA2 region of the hippocampus in cases of PART with either a high stage (Braak IV) or a high burden of neuritic tau pathology. There was also loss of synaptophysin intensity in CA3 associated with a high stage or high burden of tau pathology. Loss of synaptophysin signal was present in AD, but the pattern was distinct from that seen in PART. These novel findings suggest the presence of synaptic loss in PART associated with either a high hippocampal tau burden or a Braak stage IV. These synaptic changes raise the possibility that synaptic loss in PART could contribute to cognitive impairment, though future studies including cognitive assessments are needed to address this question.
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Affiliation(s)
- Meaghan Morris
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Gabrielle I Coste
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Javier Redding-Ochoa
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Haidan Guo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Austin R Graves
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD
- Kavli Neuroscience Discovery Institute, Baltimore, MD
- Department of Biomedical Engineering, Johns Hopkins University School of Engineering, Baltimore, MD
| | - Juan C Troncoso
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Richard L Huganir
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD
- Kavli Neuroscience Discovery Institute, Baltimore, MD
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4
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Li Y, Wang H, Gao Y, Zhang R, Liu Q, Xie W, Liu Z, Geng D, Wang L. Circ-Vps41 positively modulates Syp and its overexpression improves memory ability in aging mice. Front Mol Neurosci 2022; 15:1037912. [PMID: 36533129 PMCID: PMC9756809 DOI: 10.3389/fnmol.2022.1037912] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 11/18/2022] [Indexed: 10/14/2023] Open
Abstract
INTRODUCTION Age is an established risk factor for neurodegenerative disorders. Aging-related cognitive decline is a common cause of memory impairment in aging individuals, in which hippocampal synaptic plasticity and hippocampus-dependent memory formation are damaged. Circular RNAs (circRNAs) have been reported in many cognitive disorders, but their role in aging-related memory impairment is unclear.Methods: In this study, we aimed to investigate the effects of circ-Vps41 on aging-related hippocampus-dependent memory impairment and explore the potential mechanisms. Here, D-galactose was used to produce a conventional aging model resulting in memory dysfunction. RESULTS Circ-Vps41 was significantly downregulated in D-galactose-induced aging in vitro and in vivo. The overexpression of circ-Vps41 could upregulate synaptophysin (Syp), thereby promoting the synaptic plasticity and alleviating cognitive impairment in aging mice. Mechanistically, we found that circ-Vps41 upregulated Syp expression by physically binding to miR-24-3p. Moreover, the miR-24-3p mimics reversed the circ-Vps41 overexpression-induced increase in Syp expression. DISCUSSION Overexpression of circ-Vps41 alleviated the synaptic plasticity and memory dysfunction via the miR-24-3p/Syp axis. These findings revealed circ-Vps41 regulatory network and provided new insights into its potential mechanisms for improving aging-related learning and memory impairment.
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Affiliation(s)
- Yibo Li
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Hongfang Wang
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yanjing Gao
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Runjiao Zhang
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Qing Liu
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Wenmeng Xie
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Ziyu Liu
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Dandan Geng
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Lei Wang
- Department of Human Anatomy, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, Hebei, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei, China
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5
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Freire-Cobo C, Edler MK, Varghese M, Munger E, Laffey J, Raia S, In SS, Wicinski B, Medalla M, Perez SE, Mufson EJ, Erwin JM, Guevara EE, Sherwood CC, Luebke JI, Lacreuse A, Raghanti MA, Hof PR. Comparative neuropathology in aging primates: A perspective. Am J Primatol 2021; 83:e23299. [PMID: 34255875 PMCID: PMC8551009 DOI: 10.1002/ajp.23299] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 05/24/2021] [Accepted: 06/06/2021] [Indexed: 12/27/2022]
Abstract
While humans exhibit a significant degree of neuropathological changes associated with deficits in cognitive and memory functions during aging, non-human primates (NHP) present with more variable expressions of pathological alterations among individuals and species. As such, NHP with long life expectancy in captivity offer an opportunity to study brain senescence in the absence of the typical cellular pathology caused by age-related neurodegenerative illnesses commonly seen in humans. Age-related changes at neuronal population, single cell, and synaptic levels have been well documented in macaques and marmosets, while age-related and Alzheimer's disease-like neuropathology has been characterized in additional species including lemurs as well as great apes. We present a comparative overview of existing neuropathologic observations across the primate order, including classic age-related changes such as cell loss, amyloid deposition, amyloid angiopathy, and tau accumulation. We also review existing cellular and ultrastructural data on neuronal changes, such as dendritic attrition and spine alterations, synaptic loss and pathology, and axonal and myelin pathology, and discuss their repercussions on cellular and systems function and cognition.
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Affiliation(s)
- Carmen Freire-Cobo
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Melissa K Edler
- School of Biomedical Sciences, Kent State University, Kent, Ohio, USA
- Department of Anthropology, Kent State University, Kent, Ohio, USA
- Brain Health Research Institute, Kent State University, Kent, Ohio, USA
| | - Merina Varghese
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Emily Munger
- School of Biomedical Sciences, Kent State University, Kent, Ohio, USA
- Department of Anthropology, Kent State University, Kent, Ohio, USA
- Brain Health Research Institute, Kent State University, Kent, Ohio, USA
| | - Jessie Laffey
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Sophia Raia
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Selena S In
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Bridget Wicinski
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Maria Medalla
- Department of Anatomy and Neurobiology, Center for Systems Neuroscience, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Sylvia E Perez
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona, USA
| | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona, USA
- Department of Neurology, Barrow Neurological Institute, Phoenix, Arizona, USA
| | - Joseph M Erwin
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, USA
| | - Elaine E Guevara
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, USA
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, USA
| | - Chet C Sherwood
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, USA
| | - Jennifer I Luebke
- Department of Anatomy and Neurobiology, Center for Systems Neuroscience, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Agnès Lacreuse
- Psychological and Brain Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Mary A Raghanti
- School of Biomedical Sciences, Kent State University, Kent, Ohio, USA
- Department of Anthropology, Kent State University, Kent, Ohio, USA
- Brain Health Research Institute, Kent State University, Kent, Ohio, USA
| | - Patrick R Hof
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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6
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Arabatzis TJ, Wakley AA, McLane VD, Canonico D, Cao L. Effects of HIV gp120 on Neuroinflammation in Immunodeficient vs. Immunocompetent States. J Neuroimmune Pharmacol 2021; 16:437-453. [PMID: 32627098 PMCID: PMC7785647 DOI: 10.1007/s11481-020-09936-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 06/17/2020] [Indexed: 11/30/2022]
Abstract
HIV affects 37 million people worldwide, 25-69% of which develop HIV-associated neurocognitive disorders (HAND) regardless of antiviral treatment. HIV infection of the brain decreases cognitive function, disrupts/impairs learning and memory, and reduces quality of life for those affected. HIV-induced neuroinflammation has been associated with viral proteins such as gp120 and Tat, which remain elevated in the CNS even in patients with low peripheral viremia counts. In this study, we examined the effects of gp120 on neuroinflammation in immunodeficient vs. immunocompetent states by examining neuroinflammatory markers in gp120tg mice with or without systemic immunodeficiency caused by murine retroviral administration (LP-BM5 murine AIDS). Changes in inflammatory cytokine/chemokine mRNA expression was complex and dependent upon expression of gp120 protein, immunodeficiency status, brain region (hippocampus, frontal lobe, or striatum), and age. Gp120 expression reduced hippocampal synaptophysin expression but did not affect animals' learning/memory on the spontaneous T-maze test in our experimental conditions. Our results emphasize the critical role of the neuroinflammatory micro-environment and the peripheral immune system context in which gp120 acts. Multiple factors, particularly system-level differences in the immune response of different brain regions, need to be considered when developing treatment for HAND. Graphical Abstract.
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Affiliation(s)
- Taxiarhia J Arabatzis
- Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, 11 Hills Beach Road, Biddeford, ME, 04005, USA
- Department of Biology, University of New England College of Arts and Sciences, Biddeford, ME, USA
| | - Alexa A Wakley
- Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, 11 Hills Beach Road, Biddeford, ME, 04005, USA
| | - Virginia D McLane
- Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, 11 Hills Beach Road, Biddeford, ME, 04005, USA
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Medical College of Virginia (MCV) Campus, P.O. Box 980613, Richmond, VA, 23298-0613, USA
| | - Dalton Canonico
- Department of Biology, University of New England College of Arts and Sciences, Biddeford, ME, USA
| | - Ling Cao
- Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, 11 Hills Beach Road, Biddeford, ME, 04005, USA.
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA.
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7
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Sherwood CC, Miller SB, Karl M, Stimpson CD, Phillips KA, Jacobs B, Hof PR, Raghanti MA, Smaers JB. Invariant Synapse Density and Neuronal Connectivity Scaling in Primate Neocortical Evolution. Cereb Cortex 2020; 30:5604-5615. [PMID: 32488266 DOI: 10.1093/cercor/bhaa149] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/31/2020] [Accepted: 05/07/2020] [Indexed: 12/20/2022] Open
Abstract
Synapses are involved in the communication of information from one neuron to another. However, a systematic analysis of synapse density in the neocortex from a diversity of species is lacking, limiting what can be understood about the evolution of this fundamental aspect of brain structure. To address this, we quantified synapse density in supragranular layers II-III and infragranular layers V-VI from primary visual cortex and inferior temporal cortex in a sample of 25 species of primates, including humans. We found that synapse densities were relatively constant across these levels of the cortical visual processing hierarchy and did not significantly differ with brain mass, varying by only 1.9-fold across species. We also found that neuron densities decreased in relation to brain enlargement. Consequently, these data show that the number of synapses per neuron significantly rises as a function of brain expansion in these neocortical areas of primates. Humans displayed the highest number of synapses per neuron, but these values were generally within expectations based on brain size. The metabolic and biophysical constraints that regulate uniformity of synapse density, therefore, likely underlie a key principle of neuronal connectivity scaling in primate neocortical evolution.
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Affiliation(s)
- Chet C Sherwood
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052, USA
| | - Sarah B Miller
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Molly Karl
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052, USA
| | - Cheryl D Stimpson
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052, USA
| | | | - Bob Jacobs
- Department of Psychology, Laboratory of Quantitative Neuromorphology, Colorado College, Colorado Springs, CO 80946, USA
| | - Patrick R Hof
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mary Ann Raghanti
- Department of Anthropology, School of Biomedical Sciences, Brain Health Research Institute, Kent State University, Kent, OH 44242, USA
| | - Jeroen B Smaers
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA.,Division of Anthropology, American Museum of Natural History, New York, NY 10024, USA
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8
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Celebi-Birand D, Ardic NI, Karoglu-Eravsar ET, Sengul GF, Kafaligonul H, Adams MM. Dietary and Pharmacological Interventions That Inhibit Mammalian Target of Rapamycin Activity Alter the Brain Expression Levels of Neurogenic and Glial Markers in an Age-and Treatment-Dependent Manner. Rejuvenation Res 2020; 23:485-497. [PMID: 32279604 DOI: 10.1089/rej.2019.2297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Intermittent fasting (IF) and its mimetic, rapamycin extend lifespan and healthspan through mechanisms that are not fully understood. We investigated different short-term durations of IF and rapamycin on cellular and molecular changes in the brains of young (6-10 months) and old (26-31 months) zebrafish. Interestingly, our results showed that IF significantly lowered glucose levels while increasing DCAMKL1 in both young and old animals. This proliferative effect of IF was supported by the upregulation of foxm1 transcript in old animals. Rapamycin did not change glucose levels in young and old animals but had differential effects depending on age. In young zebrafish, proliferating cell nuclear antigen and the LC3-II/LC3-I ratio was decreased, whereas glial fibrillary acidic protein and gephyrin were decreased in old animals. The changes in proliferative markers and a marker of autophagic flux suggest an age-dependent interplay between autophagy and cell proliferation. Additionally, changes in glia and inhibitory tone suggest a suppressive effect on neuroinflammation but may push the brain toward a more excitable state. Mammalian target of rapamycin (mTOR) activity in the brain following the IF and rapamycin treatment was differentially regulated by age. Interestingly, rapamycin inhibited mTOR more potently in young animals than IF. Principal component analysis supported our conclusion that the regulatory effects of IF and rapamycin were age-specific, since we observed different patterns in the expression levels and clustering of young and old animals. Taken together, our results suggest that even a short-term duration of IF and rapamycin have significant effects in the brain at young and old ages, and that these are age and treatment dependent.
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Affiliation(s)
- Dilan Celebi-Birand
- Interdisciplinary Graduate Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey.,UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey.,Zebrafish Facility, Bilkent University Molecular Biology and Genetics, Ankara, Turkey
| | - Narin Ilgim Ardic
- Interdisciplinary Graduate Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey.,UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey.,Zebrafish Facility, Bilkent University Molecular Biology and Genetics, Ankara, Turkey
| | - Elif Tugce Karoglu-Eravsar
- Interdisciplinary Graduate Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey.,UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey.,Zebrafish Facility, Bilkent University Molecular Biology and Genetics, Ankara, Turkey
| | - Goksemin Fatma Sengul
- Interdisciplinary Graduate Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey.,UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey.,Zebrafish Facility, Bilkent University Molecular Biology and Genetics, Ankara, Turkey.,Department of Cellular Biochemistry, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Hulusi Kafaligonul
- Interdisciplinary Graduate Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey.,Zebrafish Facility, Bilkent University Molecular Biology and Genetics, Ankara, Turkey.,National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Michelle M Adams
- Interdisciplinary Graduate Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey.,UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey.,Zebrafish Facility, Bilkent University Molecular Biology and Genetics, Ankara, Turkey.,Department of Psychology, Bilkent University, Ankara, Turkey
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9
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Ryan L, Hay M, Huentelman MJ, Duarte A, Rundek T, Levin B, Soldan A, Pettigrew C, Mehl MR, Barnes CA. Precision Aging: Applying Precision Medicine to the Field of Cognitive Aging. Front Aging Neurosci 2019; 11:128. [PMID: 31231204 PMCID: PMC6568195 DOI: 10.3389/fnagi.2019.00128] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/16/2019] [Indexed: 12/13/2022] Open
Abstract
The current "one size fits all" approach to our cognitive aging population is not adequate to close the gap between cognitive health span and lifespan. In this review article, we present a novel model for understanding, preventing, and treating age-related cognitive impairment (ARCI) based on concepts borrowed from precision medicine. We will discuss how multiple risk factors can be classified into risk categories because of their interrelatedness in real life, the genetic variants that increase sensitivity to, or ameliorate, risk for ARCI, and the brain drivers or common mechanisms mediating brain aging. Rather than providing a definitive model of risk for ARCI and cognitive decline, the Precision Aging model is meant as a starting point to guide future research. To that end, after briefly discussing key risk categories, genetic risks, and brain drivers, we conclude with a discussion of steps that must be taken to move the field forward.
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Affiliation(s)
- Lee Ryan
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
| | - Meredith Hay
- Department of Physiology, University of Arizona, Tucson, AZ, United States
| | - Matt J. Huentelman
- Neurobehavioral Research Unit, Division of Neurological Disorders, Translational Genomics Research Institute (TGen), Phoenix, AZ, United States
| | - Audrey Duarte
- Center for Advanced Brain Imaging, School of Psychology, Georgia Institute of Technology, Atlanta, GA, United States
| | - Tatjana Rundek
- Clinical and Translational Research Division, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Bonnie Levin
- Neuropsychology Division, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Anja Soldan
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Corinne Pettigrew
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Matthias R. Mehl
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
| | - Carol A. Barnes
- Department of Psychology, College of Science, University of Arizona, Tucson, AZ, United States
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10
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Jarmasz JS, Stirton H, Basalah D, Davie JR, Clarren SK, Astley SJ, Del Bigio MR. Global DNA Methylation and Histone Posttranslational Modifications in Human and Nonhuman Primate Brain in Association with Prenatal Alcohol Exposure. Alcohol Clin Exp Res 2019; 43:1145-1162. [PMID: 31074890 PMCID: PMC6593679 DOI: 10.1111/acer.14052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/26/2019] [Accepted: 03/25/2019] [Indexed: 12/21/2022]
Abstract
Background Based upon experimental animal studies, the neurodevelopmental abnormalities associated with prenatal alcohol exposure (PNAE)/fetal alcohol spectrum disorder (FASD) have been attributed, at least in part, to epigenetic modifications. However, there are no direct analyses of human brain tissue. Methods Immunohistochemical detection of global epigenetic markers was performed on temporal lobe samples of autopsied fetuses and infants with documented PNAE. They were compared to age‐, sex‐, and postmortem delay‐matched control cases (18 pairs; 20 to 70.5 weeks postconception). Temporal lobe tissue from a macaque monkey model of PNAE was also studied (5.7 to 6 months of age). We used antibodies targeting 4 DNA cytosine, 4 histone methylation, and 6 histone acetylation modifications and assigned scores based upon the semiquantitatively graded intensity and proportion of positively labeled nuclei in the ventricular and subventricular zones, ependyma, temporal cortex, temporal white matter, dentate gyrus (DG), and CA1 pyramidal layer. Results Temporal changes were identified for almost all marks according to the state of maturation in the human brain. In the DG (and 3 other brain regions), a statistically significant increase in H3K9ac was associated with PNAE. Statistically significant decreases were seen among 5mC, H3K4me3, H3K9ac, H3K27ac, H4K12ac, and H4K16ac in select regions. In the macaques, H3K36me3 decreased in the DG, and the ependyma showed decreases in 5fC and H3K36me3. Conclusions In human brain, global intranuclear epigenetic modifications are brain region and maturation state‐specific. These exploratory results support the general hypothesis that PNAE is associated with a global decrease in DNA methylation, a global decrease in histone methylation, and a global increase in histone acetylation. Although the human and monkey subjects are not directly comparable in terms of brain maturation, considering the rapid temporal changes in global epigenetic modifications during brain development, interspecies comparisons may be extremely difficult.
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Affiliation(s)
- Jessica S Jarmasz
- Department of Pathology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Hannah Stirton
- Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Duaa Basalah
- Department of Pathology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - James R Davie
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Sterling K Clarren
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA.,Department of Pediatrics, University of British Columbia Faculty of Medicine, Vancouver, British Columbia
| | - Susan J Astley
- Departments of Epidemiology/Pediatrics, University of Washington, Seattle, Washington
| | - Marc R Del Bigio
- Department of Pathology, University of Manitoba, Winnipeg, Manitoba, Canada
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11
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Ramsaran AI, Schlichting ML, Frankland PW. The ontogeny of memory persistence and specificity. Dev Cogn Neurosci 2019; 36:100591. [PMID: 30316637 PMCID: PMC6969236 DOI: 10.1016/j.dcn.2018.09.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/06/2018] [Accepted: 09/25/2018] [Indexed: 02/01/2023] Open
Abstract
Interest in the ontogeny of memory blossomed in the twentieth century following the initial observations that memories from infancy and early childhood are rapidly forgotten. The intense exploration of infantile amnesia in subsequent years has led to a thorough characterization of its psychological determinants, although the neurobiology of memory persistence has long remained elusive. By contrast, other phenomena in the ontogeny of memory like infantile generalization have received relatively less attention. Despite strong evidence for reduced memory specificity during ontogeny, infantile generalization is poorly understood from psychological and neurobiological perspectives. In this review, we examine the ontogeny of memory persistence and specificity in humans and nonhuman animals at the levels of behavior and the brain. To this end, we first describe the behavioral phenotypes associated with each phenomenon. Looking into the brain, we then discuss neurobiological mechanisms in the hippocampus that contribute to the ontogeny of memory. Hippocampal neurogenesis and critical period mechanisms have recently been discovered to underlie amnesia during early development, and at the same time, we speculate that similar processes may contribute to the early bias towards memory generalization.
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Affiliation(s)
- Adam I Ramsaran
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, M5S 3G3, Canada
| | | | - Paul W Frankland
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, M5S 3G3, Canada; Department of Physiology, University of Toronto, Toronto, M5S 1A8, Canada; Institute of Medical Science, University of Toronto, Toronto, M5S 1A8, Canada; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, M5G 1M1, Canada.
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12
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Petanjek Z, Sedmak D, Džaja D, Hladnik A, Rašin MR, Jovanov-Milosevic N. The Protracted Maturation of Associative Layer IIIC Pyramidal Neurons in the Human Prefrontal Cortex During Childhood: A Major Role in Cognitive Development and Selective Alteration in Autism. Front Psychiatry 2019; 10:122. [PMID: 30923504 PMCID: PMC6426783 DOI: 10.3389/fpsyt.2019.00122] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 02/18/2019] [Indexed: 12/12/2022] Open
Abstract
The human specific cognitive shift starts around the age of 2 years with the onset of self-awareness, and continues with extraordinary increase in cognitive capacities during early childhood. Diffuse changes in functional connectivity in children aged 2-6 years indicate an increase in the capacity of cortical network. Interestingly, structural network complexity does not increase during this time and, thus, it is likely to be induced by selective maturation of a specific neuronal subclass. Here, we provide an overview of a subclass of cortico-cortical neurons, the associative layer IIIC pyramids of the human prefrontal cortex. Their local axonal collaterals are in control of the prefrontal cortico-cortical output, while their long projections modulate inter-areal processing. In this way, layer IIIC pyramids are the major integrative element of cortical processing, and changes in their connectivity patterns will affect global cortical functioning. Layer IIIC neurons have a unique pattern of dendritic maturation. In contrast to other classes of principal neurons, they undergo an additional phase of extensive dendritic growth during early childhood, and show characteristic molecular changes. Taken together, circuits associated with layer IIIC neurons have the most protracted period of developmental plasticity. This unique feature is advanced but also provides a window of opportunity for pathological events to disrupt normal formation of cognitive circuits involving layer IIIC neurons. In this manuscript, we discuss how disrupted dendritic and axonal maturation of layer IIIC neurons may lead into global cortical disconnectivity, affecting development of complex communication and social abilities. We also propose a model that developmentally dictated incorporation of layer IIIC neurons into maturing cortico-cortical circuits between 2 to 6 years will reveal a previous (perinatal) lesion affecting other classes of principal neurons. This "disclosure" of pre-existing functionally silent lesions of other neuronal classes induced by development of layer IIIC associative neurons, or their direct alteration, could be found in different forms of autism spectrum disorders. Understanding the gene-environment interaction in shaping cognitive microcircuitries may be fundamental for developing rehabilitation and prevention strategies in autism spectrum and other cognitive disorders.
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Affiliation(s)
- Zdravko Petanjek
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Dora Sedmak
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Domagoj Džaja
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Ana Hladnik
- Department of Anatomy and Clinical Anatomy, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Mladen Roko Rašin
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, United States
| | - Nataša Jovanov-Milosevic
- Department of Neuroscience, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Center of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Medical Biology, School of Medicine, University of Zagreb, Zagreb, Croatia
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13
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Goncharova K, Lozinska L, Arevalo Sureda E, Woliński J, Weström B, Pierzynowski S. Importance of neonatal immunoglobulin transfer for hippocampal development and behaviour in the newborn pig. PLoS One 2017; 12:e0180002. [PMID: 28658291 PMCID: PMC5489200 DOI: 10.1371/journal.pone.0180002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/07/2017] [Indexed: 01/02/2023] Open
Abstract
Neurological disorders are among the main clinical problems affecting preterm children and often result in the development of communication and learning disabilities later in life. Several factors are of importance for brain development, however the role of immunoglobulins (passive immunity transfer) has not yet been investigated. Piglets are born agammaglobulinemic, as a result of the lack of transfer of maternal immunoglobulins in utero, thus, they serve as an ideal model to mimic the condition of immunoglobulin deficiency in preterm infants. Thirty six, unsuckled newborn piglets were fed an infant formula or colostrum and supplemented orally or intravenously with either species-specific or foreign immunoglobulin and then compared to both newborn and sow-reared piglets. Two days after the piglets were born behavioural tests (novel recognition and olfactory discrimination of conspecifics scent) were performed, after which the piglets were sacrificed and blood, cerebrospinal fluid and hippocampi samples were collected for analyses. Both parameters of neuronal plasticity (neuronal maturation and synapse-associated proteins) and behavioural test parameters appeared to be improved by the appearance of species-specific porcine immunoglulin in the circulation and cerebrospinal fluid of the piglets. In conclusion, we postulate possible positive clinical effects following intravenous infusion of human immunoglobulin in terms of neuronal plasticity and cognitive function in preterm infants born with low blood immunoglobulin levels.
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Affiliation(s)
- Kateryna Goncharova
- Department of Biology, Lund University, Lund, Sweden
- R&D Anara AB, Trelleborg, Sweden
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland
- * E-mail: ,
| | - Liudmyla Lozinska
- Department of Biology, Lund University, Lund, Sweden
- R&D Anara AB, Trelleborg, Sweden
| | | | - Jarosław Woliński
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland
| | - Björn Weström
- Department of Biology, Lund University, Lund, Sweden
| | - Stefan Pierzynowski
- Department of Biology, Lund University, Lund, Sweden
- R&D Anara AB, Trelleborg, Sweden
- Department of Medical Biology, Institute of Rural Health, Lublin, Poland
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14
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Shapiro LP, Parsons RG, Koleske AJ, Gourley SL. Differential expression of cytoskeletal regulatory factors in the adolescent prefrontal cortex: Implications for cortical development. J Neurosci Res 2017; 95:1123-1143. [PMID: 27735056 PMCID: PMC5352542 DOI: 10.1002/jnr.23960] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 09/04/2016] [Accepted: 09/12/2016] [Indexed: 12/27/2022]
Abstract
The prevalence of depression, anxiety, schizophrenia, and drug and alcohol use disorders peaks during adolescence. Further, up to 50% of "adult" mental health disorders emerge in adolescence. During adolescence, the prefrontal cortex (PFC) undergoes dramatic structural reorganization, in which dendritic spines and synapses are refined, pruned, and stabilized. Understanding the molecular mechanisms that underlie these processes should help to identify factors that influence the development of psychiatric illness. Here we briefly discuss the anatomical connections of the medial and orbital prefrontal cortex (mPFC and OFC, respectively). We then present original findings suggesting that dendritic spines on deep-layer excitatory neurons in the mouse mPFC and OFC prune at different adolescent ages, with later pruning in the OFC. In parallel, we used Western blotting to define levels of several cytoskeletal regulatory proteins during early, mid-, and late adolescence, focusing on tropomyosin-related kinase receptor B (TrkB) and β1-integrin-containing receptors and select signaling partners. We identified regional differences in the levels of several proteins in early and midadolescence that then converged in early adulthood. We also observed age-related differences in TrkB levels, both full-length and truncated isoforms, Rho-kinase 2, and synaptophysin in both PFC subregions. Finally, we identified changes in protein levels in the dorsal and ventral hippocampus that were distinct from those in the PFC. We conclude with a general review of the manner in which TrkB- and β1-integrin-mediated signaling influences neuronal structure in the postnatal brain. Elucidating the role of cytoskeletal regulatory factors throughout adolescence may identify critical mechanisms of PFC development. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Lauren P Shapiro
- Molecular and Systems Pharmacology, Emory University, Atlanta, Georgia
- Departments of Pediatrics and Psychiatry and Behavioral Sciences, Emory University School of Medicine, and Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
| | - Ryan G Parsons
- Department of Psychology and Neuroscience Institute, Graduate Program in Integrative Neuroscience, Program in Neuroscience, Stony Brook University, Stony Brook, New York
| | - Anthony J Koleske
- Department of Molecular Biophysics and Biochemistry, Department of Neurobiology, Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut
| | - Shannon L Gourley
- Departments of Pediatrics and Psychiatry and Behavioral Sciences, Emory University School of Medicine, and Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
- Graduate Program in Neuroscience, Emory University, Atlanta, Georgia
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15
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Sedmak G, Jovanov-Milošević N, Puskarjov M, Ulamec M, Krušlin B, Kaila K, Judaš M. Developmental Expression Patterns of KCC2 and Functionally Associated Molecules in the Human Brain. Cereb Cortex 2016; 26:4574-4589. [PMID: 26428952 DOI: 10.1093/cercor/bhv218] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Work on rodents demonstrated that steep upregulation of KCC2, a neuron-specific Cl- extruder of cation-chloride cotransporter (CCC) family, commences in supraspinal structures at around birth, leading to establishment of hyperpolarizing GABAergic responses. We describe spatiotemporal expression profiles of the entire CCC family in human brain. KCC2 mRNA was observed already at 10th postconceptional week (PCW) in amygdala, cerebellum, and thalamus. KCC2-immunoreactive (KCC2-ir) neurons were abundant in subplate at 18 PCW. By 25 PCW, numerous subplate and cortical plate neurons became KCC2-ir. The mRNA expression profiles of α- and β-isoforms of Na-K ATPase, which fuels cation-chloride cotransport, as well of tropomyosin receptor kinase B (TrkB), which promotes developmental upregulation of KCC2, were consistent with data from studies on rodents about their interactions with KCC2. Thus, in human brain, expression of KCC2 and its functionally associated proteins begins in early fetal period. Our work facilitates translation of results on CCC functions from animal studies to human and refutes the view that poor efficacy of anticonvulsants in the term human neonate is attributable to the lack of KCC2. We propose that perinatally low threshold for activation of Ca2+-dependent protease calpain renders neonates susceptible to downregulation of KCC2 by traumatic events, such as perinatal hypoxia ischemia.
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Affiliation(s)
| | | | - Martin Puskarjov
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
| | - Monika Ulamec
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Božo Krušlin
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
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16
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Crews FT, Vetreno RP, Broadwater MA, Robinson DL. Adolescent Alcohol Exposure Persistently Impacts Adult Neurobiology and Behavior. Pharmacol Rev 2016; 68:1074-1109. [PMID: 27677720 PMCID: PMC5050442 DOI: 10.1124/pr.115.012138] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Adolescence is a developmental period when physical and cognitive abilities are optimized, when social skills are consolidated, and when sexuality, adolescent behaviors, and frontal cortical functions mature to adult levels. Adolescents also have unique responses to alcohol compared with adults, being less sensitive to ethanol sedative-motor responses that most likely contribute to binge drinking and blackouts. Population studies find that an early age of drinking onset correlates with increased lifetime risks for the development of alcohol dependence, violence, and injuries. Brain synapses, myelination, and neural circuits mature in adolescence to adult levels in parallel with increased reflection on the consequence of actions and reduced impulsivity and thrill seeking. Alcohol binge drinking could alter human development, but variations in genetics, peer groups, family structure, early life experiences, and the emergence of psychopathology in humans confound studies. As adolescence is common to mammalian species, preclinical models of binge drinking provide insight into the direct impact of alcohol on adolescent development. This review relates human findings to basic science studies, particularly the preclinical studies of the Neurobiology of Adolescent Drinking in Adulthood (NADIA) Consortium. These studies focus on persistent adult changes in neurobiology and behavior following adolescent intermittent ethanol (AIE), a model of underage drinking. NADIA studies and others find that AIE results in the following: increases in adult alcohol drinking, disinhibition, and social anxiety; altered adult synapses, cognition, and sleep; reduced adult neurogenesis, cholinergic, and serotonergic neurons; and increased neuroimmune gene expression and epigenetic modifiers of gene expression. Many of these effects are specific to adolescents and not found in parallel adult studies. AIE can cause a persistence of adolescent-like synaptic physiology, behavior, and sensitivity to alcohol into adulthood. Together, these findings support the hypothesis that adolescent binge drinking leads to long-lasting changes in the adult brain that increase risks of adult psychopathology, particularly for alcohol dependence.
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Affiliation(s)
- Fulton T Crews
- Bowles Center for Alcohol Studies (F.T.C., R.P.V., M.A.B., D.L.R.), Department of Psychiatry (F.T.C., D.L.R.), and Department of Pharmacology (F.T.C.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Ryan P Vetreno
- Bowles Center for Alcohol Studies (F.T.C., R.P.V., M.A.B., D.L.R.), Department of Psychiatry (F.T.C., D.L.R.), and Department of Pharmacology (F.T.C.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Margaret A Broadwater
- Bowles Center for Alcohol Studies (F.T.C., R.P.V., M.A.B., D.L.R.), Department of Psychiatry (F.T.C., D.L.R.), and Department of Pharmacology (F.T.C.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Donita L Robinson
- Bowles Center for Alcohol Studies (F.T.C., R.P.V., M.A.B., D.L.R.), Department of Psychiatry (F.T.C., D.L.R.), and Department of Pharmacology (F.T.C.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
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Erythropoietin Restores Long-Term Neurocognitive Function Involving Mechanisms of Neuronal Plasticity in a Model of Hyperoxia-Induced Preterm Brain Injury. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:9247493. [PMID: 27493706 PMCID: PMC4963567 DOI: 10.1155/2016/9247493] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/31/2016] [Accepted: 06/13/2016] [Indexed: 12/22/2022]
Abstract
Cerebral white and grey matter injury is the leading cause of an adverse neurodevelopmental outcome in prematurely born infants. High oxygen concentrations have been shown to contribute to the pathogenesis of neonatal brain damage. Here, we focused on motor-cognitive outcome up to the adolescent and adult age in an experimental model of preterm brain injury. In search of the putative mechanisms of action we evaluated oligodendrocyte degeneration, myelination, and modulation of synaptic plasticity-related molecules. A single dose of erythropoietin (20,000 IU/kg) at the onset of hyperoxia (24 hours, 80% oxygen) in 6-day-old Wistar rats improved long-lasting neurocognitive development up to the adolescent and adult stage. Analysis of white matter structures revealed a reduction of acute oligodendrocyte degeneration. However, erythropoietin did not influence hypomyelination occurring a few days after injury or long-term microstructural white matter abnormalities detected in adult animals. Erythropoietin administration reverted hyperoxia-induced reduction of neuronal plasticity-related mRNA expression up to four months after injury. Thus, our findings highlight the importance of erythropoietin as a neuroregenerative treatment option in neonatal brain injury, leading to improved memory function in adolescent and adult rats which may be linked to increased neuronal network connectivity.
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Giovanoli S, Weber-Stadlbauer U, Schedlowski M, Meyer U, Engler H. Prenatal immune activation causes hippocampal synaptic deficits in the absence of overt microglia anomalies. Brain Behav Immun 2016; 55:25-38. [PMID: 26408796 DOI: 10.1016/j.bbi.2015.09.015] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 12/11/2022] Open
Abstract
Prenatal exposure to infectious or inflammatory insults can increase the risk of developing neuropsychiatric disorder in later life, including schizophrenia, bipolar disorder, and autism. These brain disorders are also characterized by pre- and postsynaptic deficits. Using a well-established mouse model of maternal exposure to the viral mimetic polyriboinosinic-polyribocytidilic acid [poly(I:C)], we examined whether prenatal immune activation might cause synaptic deficits in the hippocampal formation of pubescent and adult offspring. Based on the widely appreciated role of microglia in synaptic pruning, we further explored possible associations between synaptic deficits and microglia anomalies in offspring of poly(I:C)-exposed and control mothers. We found that prenatal immune activation induced an adult onset of presynaptic hippocampal deficits (as evaluated by synaptophysin and bassoon density). The early-life insult further caused postsynaptic hippocampal deficits in pubescence (as evaluated by PSD95 and SynGAP density), some of which persisted into adulthood. In contrast, prenatal immune activation did not change microglia (or astrocyte) density, nor did it alter their activation phenotypes. The prenatal manipulation did also not cause signs of persistent systemic inflammation. Despite the absence of overt glial anomalies or systemic inflammation, adult offspring exposed to prenatal immune activation displayed increased hippocampal IL-1β levels. Taken together, our findings demonstrate that age-dependent synaptic deficits and abnormal pro-inflammatory cytokine expression can occur during postnatal brain maturation in the absence of microglial anomalies or systemic inflammation.
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Affiliation(s)
- Sandra Giovanoli
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
| | - Ulrike Weber-Stadlbauer
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland; Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Urs Meyer
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland; Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland.
| | - Harald Engler
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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Morphometric analysis of the age-related changes of synaptophysin immunoreactivity in the human parahippocampal region. J ANAT SOC INDIA 2015. [DOI: 10.1016/j.jasi.2015.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Salucci S, Ambrogini P, Lattanzi D, Betti M, Gobbi P, Galati C, Galli F, Cuppini R, Minelli A. Maternal dietary loads of alpha-tocopherol increase synapse density and glial synaptic coverage in the hippocampus of adult offspring. Eur J Histochem 2014; 58:2355. [PMID: 24998923 PMCID: PMC4083323 DOI: 10.4081/ejh.2014.2355] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/11/2014] [Accepted: 03/12/2014] [Indexed: 01/12/2023] Open
Abstract
An increased intake of the antioxidant α-Tocopherol (vitamin E) is recommended in complicated pregnancies, to prevent free radical damage to mother and fetus. However, the anti-PKC and antimitotic activity of α-Tocopherol raises concerns about its potential effects on brain development. Recently, we found that maternal dietary loads of α-Tocopherol through pregnancy and lactation cause developmental deficit in hippocampal synaptic plasticity in rat offspring. The defect persisted into adulthood, with behavioral alterations in hippocampus-dependent learning. Here, using the same rat model of maternal supplementation, ultrastructural morphometric studies were carried out to provide mechanistic interpretation to such a functional impairment in adult offspring by the occurrence of long-term changes in density and morphological features of hippocampal synapses. Higher density of axo-spinous synapses was found in CA1 stratum radiatum of α-Tocopherol-exposed rats compared to controls, pointing to a reduced synapse pruning. No morphometric changes were found in synaptic ultrastructural features, i.e., perimeter of axon terminals, length of synaptic specializations, extension of bouton-spine contact. Glia-synapse anatomical relationship was also affected. Heavier astrocytic coverage of synapses was observed in Tocopherol-treated offspring, notably surrounding axon terminals; moreover, the percentage of synapses contacted by astrocytic endfeet at bouton-spine interface (tripartite synapses) was increased. These findings indicate that gestational and neonatal exposure to supranutritional tocopherol intake can result in anatomical changes of offspring hippocampus that last through adulthood. These include a surplus of axo-spinous synapses and an aberrant glia-synapse relationship, which may represent the morphological signature of previously described alterations in synaptic plasticity and hippocampus-dependent learning.
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The effects of prenatal and postnatal environmental interaction: prenatal environmental adaptation hypothesis. ACTA ACUST UNITED AC 2013; 107:483-92. [PMID: 23624396 DOI: 10.1016/j.jphysparis.2013.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 04/13/2013] [Accepted: 04/15/2013] [Indexed: 01/23/2023]
Abstract
Adverse antenatal maternal environments during pregnancy influence fetal development that consequently increases risks of mental health problems including psychiatric disorders in offspring. Therefore, behavioral and brain alterations caused by adverse prenatal environmental conditions are generally considered as deficits. In this article, we propose a novel hypothesis, along with summarizing a body of literatures supporting it, that fetal neurodevelopmental alterations, particularly synaptic network changes occurring in the prefrontal cortex, associated with adverse prenatal environmental conditions may be adaptation to cope with expected severe postnatal environments, and therefore, psychiatric disorders may be able to be understood as adaptive strategies against severe environmental conditions through evolution. It is hoped that the hypothesis presented in this article stimulates and opens a new venue on research toward understanding of biological mechanisms and therapeutic treatments of psychiatric disorders.
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Abstract
Postnatal cortical synaptic development is characterized by stages of exuberant growth, pruning, and stabilization during adulthood. How gene expression orchestrates these stages of synaptic development is poorly understood. Here we report that synaptic growth-related gene expression alone does not determine cortical synaptic density changes across the human lifespan, but instead, the dynamics of cortical synaptic density can be accurately simulated by a first-order kinetic model of synaptic growth and elimination that incorporates two separate gene expression patterns. Surprisingly, modeling of cortical synaptic density is optimized when genes related to oligodendrocytes are used to determine synaptic elimination rates. Expression of synaptic growth and oligodendrocyte genes varies regionally, resulting in different predictions of synaptic density among cortical regions that concur with previous regional data in humans. Our analysis suggests that modest rates of synaptic growth persist in adulthood, but that this is counterbalanced by increasing rates of synaptic elimination, resulting in stable synaptic number and ongoing synaptic turnover in the human adult cortex. Our approach provides a promising avenue for exploring how complex interactions among genes may contribute to neurobiological phenomena across the human lifespan.
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Huxter JR, Miranda JA, Dias R. The hippocampal physiology of approaching middle-age: early indicators of change. Hippocampus 2012; 22:1923-40. [PMID: 22674542 DOI: 10.1002/hipo.22027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2012] [Indexed: 12/24/2022]
Abstract
Age-related cognitive decline presents serious lifestyle challenges, and anatomical changes to the hippocampus are often implicated in clinical conditions later in life. However, relatively little is known about how hippocampal physiology is altered in the transition to middle-age, when early detection may offer the best opportunity for successful treatment. High-yield extracellular recording is a powerful tool for understanding brain function in freely moving animals at single-cell resolution and with millisecond precision. We used this technique to characterize changes to hippocampal physiology associated with maturation in 35-week-old rats. Combining a series of behavioral tasks with recordings of large numbers of neurons, local field potentials (LFP), and network patterns of activation, we were able to generate a comprehensive picture based on more than 25 different assays for each subject. Notable changes associated with aging included increased firing rates in interneurons, reduced LFP power but increased frequency in the 4-12 Hz theta band, and impairment in hippocampal pattern-separation for different environments. General properties of pyramidal cell firing and spatial map integrity were preserved. There was no impairment in theta phase-precession, experience-dependent place field expansion, or sleep reactivation of waking network patterns. There were however changes in foraging strategy and behavioral responses to the introduction of a novel environment. Taken together the results reveal a diverse pattern of changes which are of increasing relevance in an aging population. They also highlight areas where high-yield electrophysiological assays can be used to provide the sensitivity and throughput required for pre-clinical drug-discovery programs.
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Affiliation(s)
- John R Huxter
- Neusentis, Pfizer Ltd., The Portway Building, Granta Park, Great Abington, United Kingdom.
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24
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Haley GE, Eghlidi DH, Kohama SG, Urbanski HF, Raber J. Association of microtubule associated protein-2, synaptophysin, and apolipoprotein E mRNA and protein levels with cognition and anxiety levels in aged female rhesus macaques. Behav Brain Res 2012; 232:1-6. [PMID: 22475553 DOI: 10.1016/j.bbr.2012.03.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 03/16/2012] [Accepted: 03/20/2012] [Indexed: 02/06/2023]
Abstract
The dendritic protein microtubule associated protein 2 (MAP-2), the presynaptic marker synaptophysin (SYN), and apolipoprotein E (APOE), a protein which plays a role in lipid transport and metabolism and affects synaptic activity show changes with age. We analyzed post-mortem tissue from aged female rhesus macaques cognitively tested in a spatial maze and classified as good spatial performers (GSP) or poor spatial performers (PSP) and behaviorally tested in a playroom and classified as bold or reserved animals. MAP2, SYN, and APOE mRNA and protein levels in the prefrontal cortex (PFC), hippocampus, and amygdala, were assessed using qRT-PCR and western blot. In the amygdala, bold monkeys had higher levels of MAP2 and SYN mRNA than reserved monkeys. MAP2 mRNA correlated positively with amygdala size on the right, left, and combined left and right sides, while SYN mRNA levels correlated positively with the size of the right amygdala. In the hippocampus, SYN and APOE protein levels were higher in GSP than PSP animals. Thus, in aged nonhuman primates, classification of measures of anxiety is associated with differences in selected mRNA, but not protein, levels. In contrast, classification of cognitive performance is associated with differences in selected protein, but not mRNA, levels.
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Affiliation(s)
- Gwendolen E Haley
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA
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25
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Abstract
The literature on the neuroanatomical changes that occur during normal, non-demented aging is reviewed here with an emphasis on the improved accuracy of studies that use stereological techniques. Loss of neural tissue involved in cognition occurs during aging of humans as well as the other mammals that have been examined. There is considerable regional specificity within the cerebral cortex and the hippocampus in both the degree and cellular basis for loss. The anatomy of the prefrontal cortex is especially vulnerable to the effects of aging while the major subfields of the hippocampus are not. A loss of neurons, dendrites and synapses has been documented, as well as changes in neurotransmitter systems, in some regions of the cortex and hippocampus but not others. Species differences are also apparent in the cortical white matter and the corpus callosum where there are indications of loss of myelin in humans, but most evidence favors preservation in rats. The examination of whether the course of neuroanatomical aging is altered by hormone replacement in females is just beginning. When hormone replacement is started close to the time of cycle cessation, there are indications in humans and rats that replacement can preserve neural tissue but there is some variability due to the type of hormones and regimen of administration.
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Affiliation(s)
- Janice M Juraska
- Department of Psychology and Program in Neuroscience, University of Illinois, 603 E Daniel, Champaign, IL, 61820, USA,
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26
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Webster MJ, Elashoff M, Weickert CS. Molecular evidence that cortical synaptic growth predominates during the first decade of life in humans. Int J Dev Neurosci 2010; 29:225-36. [PMID: 20888897 DOI: 10.1016/j.ijdevneu.2010.09.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 09/03/2010] [Accepted: 09/07/2010] [Indexed: 01/02/2023] Open
Abstract
Theories concerning the pathology of human neurodevelopmental disorders that emerge in adolescence, such as schizophrenia, often hypothesize that there may be a failure of normal cortical synaptic loss or pruning. However, direct evidence that synaptic regression is a major developmental event in the adolescent human cortex is limited. Furthermore, developmental work in rodents suggested that synaptic regression in adolescence is not a major feature of cortical development. Thus, we set out to determine when and to what extent molecular markers of synaptic terminals [synaptophysin (SYP), SNAP-25, syntaxin1A (STX1A), and vesicle-associated membrane protein 1 (VAMP1)] are reduced during postnatal human life spanning from 1 month to 45 years (n = 69) using several different quantitative methods, microarray, qPCR and immunoblotting. We found little evidence for a consistent decrease in synaptic-related molecular markers at any time point, but instead found clear patterns of gradual increases in expression of some presynaptic markers with postnatal age (including SNAP-25, VAMP1 and complexin 1 (CPLX1) mRNAs and 6/6 presynaptic proteins evaluated). A measure of synaptic plasticity [growth-associated protein of 43 kDa (GAP-43)] was elevated in neonates, and continued robust expression throughout life. Since CPLX1 protein is enriched in inhibitory terminals we also tested if the protein product of complexin 2 (CPLX2), which is enriched in excitatory neurons, is more specifically reduced in development. In contrast to CPLX1, which showed a steady increase in both mRNA and protein levels during postnatal development (both r > 0.58, p < 0.001), CPLX2 mRNA decreased from infants to toddlers (r = -0.56, p < 0.001), while CPLX2 protein showed a steady increase until young adulthood (r = 0.55, p < 0.001). Furthermore, we found that indices of the dendrites [microtubule associated protein 2 (MAP2)] and spines (spinophilin and postsynaptic density protein of 95 kDa (PSD95)] showed some evidence of reduction over time at the mRNA level but the opposite pattern, of a developmental increase, was found for PSD95 and spinophilin protein levels. Taken together, the postnatal changes in molecular components of synapses supports the notion that growth and strengthening of synaptic elements is a major developmental event occurring in the frontal cortex throughout childhood and that maintenance of steady state levels of synapse-associated molecules may predominate during human adolescence.
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Affiliation(s)
- Maree J Webster
- Stanley Medical Research Institute, 9800 Medical Center Drive, Rockville, MD 20850, USA.
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27
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Haley GE, Kohama SG, Urbanski HF, Raber J. Age-related decreases in SYN levels associated with increases in MAP-2, apoE, and GFAP levels in the rhesus macaque prefrontal cortex and hippocampus. AGE (DORDRECHT, NETHERLANDS) 2010; 32:283-296. [PMID: 20640549 PMCID: PMC2926858 DOI: 10.1007/s11357-010-9137-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 02/16/2010] [Indexed: 05/29/2023]
Abstract
Loss of synaptic integrity in the hippocampus and prefrontal cortex (PFC) may play an integral role in age-related cognitive decline. Previously, we showed age-related increases in the dendritic marker microtubule associated protein 2 (MAP-2) and the synaptic marker synaptophysin (SYN) in mice. Similarly, apolipoprotein E (apoE), involved in lipid transport and metabolism, and glial fibrillary acidic protein (GFAP), a glia specific marker, increase with age in rodents. In this study, we assessed whether these four proteins show similar age-related changes in a nonhuman primate, the rhesus macaque. Free-floating sections from the PFC and hippocampus from adult, middle-aged, and aged rhesus macaques were immunohistochemically labeled for MAP-2, SYN, apoE, and GFAP. Protein levels were measured as area occupied by fluorescence using confocal microscopy as well as by Western blot. In the PFC and hippocampus of adult and middle-aged animals, the levels of SYN, apoE, and GFAP immunoreactivity were comparable but there was a trend towards higher MAP-2 levels in middle-aged than adult animals. There was significantly less SYN and more MAP-2, apoE, and GFAP immunoreactivity in the PFC and hippocampus of aged animals compared to adult or middle-aged animals. Thus, the age-related changes in MAP-2, apoE, and GFAP levels were similar to those previously observed in rodents. On the other hand, the age-related changes in SYN levels were not, but were similar to those previously observed in the aging human brain. Taken together, these data emphasize the value of the rhesus macaque as a pragmatic translational model for human brain aging.
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Affiliation(s)
- Gwendolen E. Haley
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239 USA
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
| | - Steven G. Kohama
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
| | - Henryk F. Urbanski
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239 USA
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239 USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239 USA
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239 USA
- 3181 SW Sam Jackson Pkwy, Mail Code L-470, Portland, OR 97239 USA
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28
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Cullen DK, Gilroy ME, Irons HR, Laplaca MC. Synapse-to-neuron ratio is inversely related to neuronal density in mature neuronal cultures. Brain Res 2010; 1359:44-55. [PMID: 20800585 DOI: 10.1016/j.brainres.2010.08.058] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 08/16/2010] [Accepted: 08/19/2010] [Indexed: 12/23/2022]
Abstract
Synapse formation is a fundamental process in neurons that occurs throughout development, maturity, and aging. Although these stages contain disparate and fluctuating numbers of mature neurons, tactics employed by neuronal networks to modulate synapse number as a function of neuronal density are not well understood. The goal of this study was to utilize an in vitro model to assess the influence of cell density and neuronal maturity on synapse number and distribution. Specifically, cerebral cortical neurons were plated in planar culture at densities ranging from 10 to 5000 neurons/mm², and synapse number and distribution were evaluated via immunocytochemistry over 21 days in vitro (DIV). High-resolution confocal microscopy revealed an elaborate three-dimensional distribution of neurites and synapses across the heights of high-density neuronal networks by 21 DIV, which were up to 18 μm thick, demonstrating the complex degree of spatial interactions even in planar high-density cultures. At 7 DIV, the mean number of synapses per neuron was less than 5, and this did not vary as a function of neuronal density. However, by 21 DIV, the number of synapses per neuron had jumped 30- to 80-fold, and the synapse-to-neuron ratio was greatest at lower neuronal densities (< 500 neurons/mm²; mean approximately 400 synapses/neuron) compared to mid and higher neuronal densities (500-4500 neurons/mm²; mean of approximately 150 synapses/neuron) (p<0.05). These results suggest a relationship between neuronal density and synapse number that may have implications in the neurobiology of developing neuronal networks as well as processes of cell death and regeneration.
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Affiliation(s)
- D Kacy Cullen
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
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29
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Sherwood CC, Duka T, Stimpson CD, Schenker NM, Garrison AR, Schapiro SJ, Baze WB, McArthur MJ, Erwin JM, Hof PR, Hopkins WD. Neocortical synaptophysin asymmetry and behavioral lateralization in chimpanzees (Pan troglodytes). Eur J Neurosci 2010; 31:1456-64. [PMID: 20384782 DOI: 10.1111/j.1460-9568.2010.07168.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Although behavioral lateralization is known to correlate with certain aspects of brain asymmetry in primates, there are limited data concerning hemispheric biases in the microstructure of the neocortex. In the present study, we investigated whether there is asymmetry in synaptophysin-immunoreactive puncta density and protein expression levels in the region of hand representation of the primary motor cortex in chimpanzees (Pan troglodytes). Synaptophysin is a presynaptic vesicle-associated protein found in nearly all synapses of the central nervous system. We also tested whether there is a relationship between hand preference on a coordinated bimanual task and the interhemispheric distribution of synaptophysin as measured by both stereologic counts of immunoreactive puncta and by Western blotting. Our results demonstrated that synaptophysin-immunoreactive puncta density is not asymmetric at the population level, whereas synaptophysin protein expression levels are significantly higher in the right hemisphere. Handedness was correlated with interindividual variation in synaptophysin-immunoreactive puncta density. As a group, left-handed and ambidextrous chimpanzees showed a rightward bias in puncta density. In contrast, puncta densities were symmetrical in right-handed chimpanzees. These findings support the conclusion that synapse asymmetry is modulated by lateralization of skilled motor behavior in chimpanzees.
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Affiliation(s)
- Chet C Sherwood
- Department of Anthropology, The George Washington University, Washington, DC 20052, USA.
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30
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Mladenovic Djordjevic A, Perovic M, Tesic V, Tanic N, Rakic L, Ruzdijic S, Kanazir S. Long-term dietary restriction modulates the level of presynaptic proteins in the cortex and hippocampus of the aging rat. Neurochem Int 2009; 56:250-5. [PMID: 19878701 DOI: 10.1016/j.neuint.2009.10.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 10/13/2009] [Accepted: 10/16/2009] [Indexed: 01/05/2023]
Abstract
Brain aging is related to the numerous structural and functional changes including decreased synaptic plasticity. The beneficial effects of dietary restriction (DR) are well known but insufficiently investigated at the level of plasticity-related markers. Therefore, the aim of this study was to examine the expression profiles of proteins structurally and functionally related to synapses-growth-associated protein 43 (GAP-43), synaptophysin (SPH) and alpha-synuclein (alpha-Syn), in the course of aging and in response to long-term DR. The mRNA and protein levels of three presynaptic proteins were assessed by Real Time RT-PCR and Western blotting in the cortex and hippocampus of young (6-month-old), middle-aged (12-month-old), aged (18-month-old) and old (24-month-old) male Wistar rats fed ad libitum and exposed to DR starting from 6 months of age. We observed that long-term DR modulated age-related transcriptional changes by maintaining stable mRNAs levels in the cortex. No major age-related changes of the protein levels were observed in the cortex, while the specific temporal decline was detected in the hippocampus for all three proteins. The SPH levels were decreased across lifespan (0.8-, 0.8- and 0.6-fold change at 12, 18 and 24 months), while the significant decrease of GAP-43 and alpha-Syn protein was detected at 24 months of age (0.6- and 0.7-fold decrease, respectively). Long-term DR eliminated this decline by increasing GAP-43, SPH and alpha-Syn protein levels (1.7-, 1.7- and 1.6-fold, respectively) thus reverting protein levels to the values measured in 6-month-old animals.Specific pattern of changes observed in the hippocampus identifies this structure as more vulnerable to the processes of aging and with a more pronounced response to the DR effects. The observed DR-induced stabilization of the levels of three presynaptic proteins indicates the beneficial effect of DR on age-related decline in the capacity for synaptic plasticity.
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31
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VanGuilder HD, Brucklacher RM, Patel K, Ellis RW, Freeman WM, Barber AJ. Diabetes downregulates presynaptic proteins and reduces basal synapsin I phosphorylation in rat retina. Eur J Neurosci 2008; 28:1-11. [DOI: 10.1111/j.1460-9568.2008.06322.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Canas PM, Duarte JMN, Rodrigues RJ, Köfalvi A, Cunha RA. Modification upon aging of the density of presynaptic modulation systems in the hippocampus. Neurobiol Aging 2008; 30:1877-84. [PMID: 18304697 DOI: 10.1016/j.neurobiolaging.2008.01.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 12/29/2007] [Accepted: 01/08/2008] [Indexed: 10/22/2022]
Abstract
Different presynaptic neuromodulation systems have been explored as possible targets to manage neurodegenerative diseases. However, most studies used young adult animals whereas neurodegenerative diseases are prevalent in the elderly. Thus, we now explored by Western blot analysis how the density of different presynaptic markers and receptors changes with aging in rat hippocampal synaptosomes (purified nerve terminals). Compared to synaptosomal membranes from 2-month-old rats, the density of presynaptic proteins (synaptophysin or SNAP-25) decreased at 18-24 months. In parallel, markers of glutamatergic terminals (vGluT1 or vGluT2) and cholinergic terminal markers (vAChT) constantly decreased with aging from 12 to 18 months onwards, whereas the densities of GABAergic (vGAT) only decreased after 24 months. Inhibitory A(1) and CB(1) receptor density tended to decrease with aging, whereas facilitatory mGluR5 and P2Y1 receptor density was roughly constant and facilitatory A(2A) receptor density increased at 18-24 months. Thus aging causes an imbalance of excitatory versus inhibitory nerve terminal markers and causes a predominant decrease of inhibitory rather than facilitatory presynaptic modulation systems.
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Affiliation(s)
- Paula M Canas
- Centre for Neuroscience of Coimbra, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal
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Price G, Cercignani M, Parker GJM, Altmann DR, Barnes TRE, Barker GJ, Joyce EM, Ron MA. White matter tracts in first-episode psychosis: a DTI tractography study of the uncinate fasciculus. Neuroimage 2007; 39:949-55. [PMID: 17988894 PMCID: PMC2387199 DOI: 10.1016/j.neuroimage.2007.09.012] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 08/31/2007] [Accepted: 09/07/2007] [Indexed: 11/17/2022] Open
Abstract
A model of disconnectivity involving abnormalities in the cortex and connecting white matter pathways may explain the symptoms and cognitive abnormalities of schizophrenia. Recently, diffusion imaging tractography has made it possible to study white matter pathways in detail, and we present here a study of patients with first-episode psychosis using this technique. We studied the uncinate fasciculus (UF), the largest white matter tract that connects the frontal and temporal lobes, two brain regions significantly implicated in schizophrenia. Nineteen patients with first-episode schizophrenia and 23 controls were studied using a probabilistic tractography algorithm (PICo). Fractional anisotropy (FA) and probability of connection were obtained for every voxel in the tract, and the group means and distributions of these variables were compared. The spread of the FA distribution in the upper tail, as measured by the squared coefficient of variance (SCV), was reduced in the left UF in the patient group, indicating that the number of voxels with high FA values was reduced in the core of the tract and suggesting the presence of changes in fibre alignment and tract coherence in the patient group. The SCV of FA was lower in females across both groups and there was no correlation between the SCV of FA and clinical ratings.
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Affiliation(s)
- Gary Price
- Institute of Neurology, University College London, Queen Square, London, UK.
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