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Crapser JD, Arreola MA, Tsourmas KI, Green KN. Microglia as hackers of the matrix: sculpting synapses and the extracellular space. Cell Mol Immunol 2021; 18:2472-2488. [PMID: 34413489 PMCID: PMC8546068 DOI: 10.1038/s41423-021-00751-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/26/2021] [Indexed: 02/08/2023] Open
Abstract
Microglia shape the synaptic environment in health and disease, but synapses do not exist in a vacuum. Instead, pre- and postsynaptic terminals are surrounded by extracellular matrix (ECM), which together with glia comprise the four elements of the contemporary tetrapartite synapse model. While research in this area is still just beginning, accumulating evidence points toward a novel role for microglia in regulating the ECM during normal brain homeostasis, and such processes may, in turn, become dysfunctional in disease. As it relates to synapses, microglia are reported to modify the perisynaptic matrix, which is the diffuse matrix that surrounds dendritic and axonal terminals, as well as perineuronal nets (PNNs), specialized reticular formations of compact ECM that enwrap neuronal subsets and stabilize proximal synapses. The interconnected relationship between synapses and the ECM in which they are embedded suggests that alterations in one structure necessarily affect the dynamics of the other, and microglia may need to sculpt the matrix to modify the synapses within. Here, we provide an overview of the microglial regulation of synapses, perisynaptic matrix, and PNNs, propose candidate mechanisms by which these structures may be modified, and present the implications of such modifications in normal brain homeostasis and in disease.
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Affiliation(s)
- Joshua D. Crapser
- grid.266093.80000 0001 0668 7243Department of Neurobiology and Behavior, University of California, Irvine, CA USA
| | - Miguel A. Arreola
- grid.266093.80000 0001 0668 7243Department of Neurobiology and Behavior, University of California, Irvine, CA USA
| | - Kate I. Tsourmas
- grid.266093.80000 0001 0668 7243Department of Neurobiology and Behavior, University of California, Irvine, CA USA
| | - Kim N. Green
- grid.266093.80000 0001 0668 7243Department of Neurobiology and Behavior, University of California, Irvine, CA USA
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Mikhalkin A, Nikitina N, Merkulyeva N. Heterochrony of postnatal accumulation of nonphosphorylated heavy‐chain neurofilament by neurons of the cat dorsal lateral geniculate nucleus. J Comp Neurol 2020; 529:1430-1441. [DOI: 10.1002/cne.25028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 08/24/2020] [Accepted: 09/02/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Aleksandr Mikhalkin
- lab Neuromorphology Pavlov Institute of Physiology RAS Makarov emb, 6 Saint‐Petersburg Russia
| | - Nina Nikitina
- lab Neuromorphology Pavlov Institute of Physiology RAS Makarov emb, 6 Saint‐Petersburg Russia
| | - Natalia Merkulyeva
- lab Neuromorphology Pavlov Institute of Physiology RAS Makarov emb, 6 Saint‐Petersburg Russia
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A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex. eNeuro 2018; 5:eN-NWR-0051-18. [PMID: 30225357 PMCID: PMC6140119 DOI: 10.1523/eneuro.0051-18.2018] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/20/2018] [Accepted: 06/29/2018] [Indexed: 12/19/2022] Open
Abstract
During early developmental windows known as critical periods (CPs) of plasticity, passive alterations in the quality and quantity of sensory inputs are sufficient to induce profound and long-lasting distortions in cortical sensory representations. With CP closure, those representations are stabilized, a process requiring the maturation of inhibitory networks and the maintenance of sufficient GABAergic tone in the cortex. In humans and rodents, however, cortical inhibition progressively decreases with advancing age, raising the possibility that the regulation of plasticity could be altered in older individuals. Here we tested the hypothesis that aging results in a destabilization of sensory representations and maladaptive dysregulated plasticity in the rat primary auditory cortex (A1). Consistent with this idea, we found that passive tone exposure is sufficient to distort frequency tuning in the A1 of older but not younger adult rats. However, we also found that these passive distortions decayed rapidly, indicating an ongoing instability of A1 tuning in the aging cortex. These changes were associated with a decrease in GABA neurotransmitter concentration and a reduction in parvalbumin and perineuronal net expression in the cortex. Finally, we show that artificially increasing GABA tone in the aging A1 is sufficient to restore representational stability and improve the retention of learning.
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Increased Synthesis of Chondroitin Sulfate Proteoglycan Promotes Adult Hippocampal Neurogenesis in Response to Enriched Environment. J Neurosci 2018; 38:8496-8513. [PMID: 30126967 DOI: 10.1523/jneurosci.0632-18.2018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 08/06/2018] [Accepted: 08/15/2018] [Indexed: 12/12/2022] Open
Abstract
Chondroitin sulfate proteoglycan (CSPG) is a candidate regulator of embryonic neurogenesis. The aim of this study was to specify the functional significance of CSPG in adult hippocampal neurogenesis using male mice. Here, we showed that neural stem cells and neuronal progenitors in the dentate gyrus were covered in part by CSPG. Pharmacological depletion of CSPG in the dentate gyrus reduced the densities of neuronal progenitors and newborn granule cells. 3D reconstruction of newborn granule cells showed that their maturation was inhibited by CSPG digestion. The novel object recognition test revealed that CSPG digestion caused cognitive memory impairment. Western blot analysis showed that expression of β-catenin in the dentate gyrus was decreased by CSPG digestion. The amount of CSPG in the dentate gyrus was increased by enriched environment (EE) and was decreased by forced swim stress. In addition, EE accelerated the recovery of CSPG expression in the dentate gyrus from the pharmacological depletion and promoted the restoration of granule cell production. Conversely, the densities of newborn granule cells were also decreased in mice that lacked chondroitin sulfate N-acetylgalactosaminyltransferase 1 (CSGalNAcT1), a key enzyme for CSPG synthesis (T1KO mice). The capacity of EE to promote granule cell production and improve cognitive memory was impaired in T1KO mice. These findings indicate that CSPG is involved in the regulation of adult hippocampal neurogenesis and suggest that increased synthesis of CSPG by CSGalNacT1 may mediate promotion of granule cell production and improvement of cognitive memory in response to EE.SIGNIFICANCE STATEMENT Chondroitin sulfate proteoglycan (CSPG) is a candidate regulator of embryonic neurogenesis. Here, we specified the role of CSPG in adult neurogenesis in the mouse hippocampus. Digestion of CSPG in the dentate gyrus impaired granule cell production and cognitive memory. Enriched environment (EE) promoted the recovery of CSPG expression and granule cell production from the CSPG digestion. Additionally, adult neurogenesis was impaired in mice that lacked a key enzyme for CSPG synthesis (T1KO mice). The capacity of EE to promote granule cell production and cognitive memory was impaired in T1KO mice. Altogether, these findings indicate that CSPG underlies adult hippocampal neurogenesis and suggest that increased synthesis of CSPG may mediate promotion of granule cell production in response to EE.
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Yamada J, Ohgomori T, Jinno S. Alterations in expression of Cat-315 epitope of perineuronal nets during normal ageing, and its modulation by an open-channel NMDA receptor blocker, memantine. J Comp Neurol 2017; 525:2035-2049. [PMID: 28271508 DOI: 10.1002/cne.24198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/06/2017] [Accepted: 02/24/2017] [Indexed: 02/04/2023]
Abstract
The perineuronal net (PNN), a specialized aggregate of the extracellular matrix, is involved in neuroprotection against oxidative stress, which is now recognized as a major contributor to age-related decline in brain functions. In this study, we investigated the age-related molecular changes of PNNs using monoclonal antibody Cat-315, which recognizes human natural killer-1 (HNK-1) glycan on aggrecan-based PNNs. Western blot analysis showed that the expression levels of Cat-315 epitope in the hippocampus were higher in middle-aged (MA, 12-month-old) mice than in young adult (YA, 2-month-old) mice. Although there were no differences in the expression levels of Cat-315 epitope between old age (OA, 20-month-old) and MA mice, Cat-315 immunoreactivity was also detected in astrocytes of OA mice. To focus on Cat-315 epitope in PNNs, we used YA and MA mice in the following experiments. Optical disector analysis showed that there were no differences in the numbers of Cat-315-positive (Cat-315+ ) PNNs between YA and MA mice. Fluorescence intensity analysis indicated that Cat-315 immunoreactivity in PNNs increased with age in the dorsal hippocampus, which is mainly involved in cognitive functions. Administration of an open-channel blocker of NMDA receptor, memantine, reduced the expression levels of Cat-315 epitope in the hippocampus. Furthermore, the numbers of glutamatergic and GABAergic terminals colocalized with Cat-315 epitope around parvalbumin-positive neurons were decreased by memantine. These findings provide novel insight into the involvement of PNNs in normal brain ageing, and suggest that memantine may counteract the age-related alterations in expression levels of Cat-315 epitope via regulation of its subcellular localization.
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Affiliation(s)
- Jun Yamada
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Tomohiro Ohgomori
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Shozo Jinno
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
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6
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Härtig W, Appel S, Suttkus A, Grosche J, Michalski D. Abolished perineuronal nets and altered parvalbumin-immunoreactivity in the nucleus reticularis thalami of wildtype and 3xTg mice after experimental stroke. Neuroscience 2016; 337:66-87. [PMID: 27634771 DOI: 10.1016/j.neuroscience.2016.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/18/2016] [Accepted: 09/03/2016] [Indexed: 12/14/2022]
Abstract
Treatment strategies for ischemic stroke are still limited, since numerous attempts were successful only in preclinical research but failed under clinical condition. To overcome this translational roadblock, clinical relevant stroke models should consider co-morbidities, age-related effects and the complex neurovascular unit (NVU) concept. The NVU includes neurons, vessels and glial cells with astrocytic endfeet in close relation to the extracellular matrix (ECM). However, the role of the ECM after stroke-related tissue damage is poorly understood and mostly neglected for treatment strategies. This study is focused on alterations of perineuronal nets (PNs) as ECM constituents and parvalbumin-containing GABAergic neurons in mice with emphasis on the nucleus reticularis thalami (NRT) in close proximity to the ischemic lesion as induced by a filament-based stroke model. One day after ischemia onset, immunofluorescence-based quantitative analyses revealed drastically declined PNs in the ischemia-affected NRT from 3- and 12-month-old wildtype and co-morbid triple-transgenic (3xTg) mice with Alzheimer-like alterations. Parvalbumin-positive cells decreased numerically in the ischemia-affected NRT, while staining intensity did not differ between the affected and non-affected hemisphere. Additional qualitative analyses demonstrated ischemia-induced loss of PNs and allocated neuropil ECM immunoreactive for aggrecan and neurocan, and impaired immunoreactivity for calbindin, the potassium channel subunit Kv3.1b and the glutamate decarboxylase isoforms GAD65 and GAD67 in the NRT. In conclusion, these data confirm PNs as highly sensitive constituents of the ECM along with impaired neuronal integrity of GABAergic neurons. Therefore, specific targeting of ECM components might appear as a promising strategy for future treatment strategies in stroke.
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Affiliation(s)
- Wolfgang Härtig
- Paul Flechsig Institute for Brain Research University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany.
| | - Simon Appel
- Paul Flechsig Institute for Brain Research University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany
| | - Anne Suttkus
- Paul Flechsig Institute for Brain Research University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany; Department of Pediatric Surgery, University Hospital Leipzig, Liebigstr. 20 A, 04103 Leipzig, Germany
| | - Jens Grosche
- Effigos GmbH, Am Deutschen Platz 4, 04103 Leipzig, Germany
| | - Dominik Michalski
- Department of Neurology, University of Leipzig, Liebigstr. 20, 04103 Leipzig, Germany
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Karetko-Sysa M, Skangiel-Kramska J, Nowicka D. Aging somatosensory cortex displays increased density of WFA-binding perineuronal nets associated with GAD-negative neurons. Neuroscience 2014; 277:734-46. [PMID: 25086318 DOI: 10.1016/j.neuroscience.2014.07.049] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/20/2014] [Accepted: 07/22/2014] [Indexed: 11/15/2022]
Abstract
The mechanisms of aging in the brain and the subsequent decrease in cognitive abilities remain elusive. While most studies refer to research conducted in old and senile animals, little is known about the early symptoms of normal, healthy aging. In this study, we examined whether perineuronal nets (PNNs), a special form of extracellular matrix (ECM) tightly associated with neurons that is thought to be involved in limiting neuronal plasticity, undergo changes in density during early aging. Using histochemistry and immunohistochemistry, we found that in middle-aged mice (1-year-old), the density of WFA-binding PNNs in the somatosensory cortex as well as in the visual cortex was increased in comparison to that in young adults (3-month-old). Moreover, in the somatosensory cortex, this increase was not associated with any of the GABAergic neuron types that were examined. We propose that early age-related changes in neuronal plasticity may be associated with this increase and can be conceptualized as the spreading of structural brakes for synaptic rearrangements.
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Affiliation(s)
- M Karetko-Sysa
- Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - J Skangiel-Kramska
- Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - D Nowicka
- Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
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Genade T, Lang DM. Resveratrol extends lifespan and preserves glia but not neurons of the Nothobranchius guentheri optic tectum. Exp Gerontol 2012; 48:202-12. [PMID: 23220248 DOI: 10.1016/j.exger.2012.11.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 11/07/2012] [Accepted: 11/26/2012] [Indexed: 12/14/2022]
Abstract
Resveratrol is reported as having neuroprotective properties, however, much of this reputation has come from research using disease and injury models of neurodegeneration and not neurodegenerative-ageing. The results published here pertain to the affect resveratrol has on neurodegenerative-ageing. Resveratrol had previously been used to extend the lifespan of Nothobranchius furzeri wherein it preserved cognition and reduced ageing-associated neurodegeneration. No cell-type specific antibodies were then identified which could be used to investigate the nature of the neurodegeneration or resveratrols effect on CNS cells. Using wholemounts stained with SMI31 anti-phospho-neurolament, GA-5 and DAKO Z0334 anti-GFAP antibodies, E587 antiserum against NCAMs and anti-tenascin-R antibodies we determined what cellular changes occurred with age in the optic tectum of Nothobranchius guentheri. We show that resveratrol-treatment extended the lifespan of N. guentheri but did not preserve neuron density of the optic tectum stratum griseum superciale even though it did reduce the proportion of degenerate (SMI31 antigen accumulating) neurons in the optic tectum. Resveratrol-treatment did prevent the ageing-dependent loss of radial glia lining the optic tectum of N. guentheri. The ageing-related loss of NCAM expression and tenascin-R expressing perineuronal nets was also prevented by resveratrol-treatment. Glial and perineuronal density as well as NCAM expression appear to correlate well with age. These results suggest that the anti-ageing properties of resveratrol in vertebrates may be unrelated to the protection of neurons.
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Affiliation(s)
- T Genade
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Private Bag X3, Observatory, 7935, South Africa.
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Zhang Z, Francisco EM, Holden JK, Dennis RG, Tommerdahl M. Somatosensory information processing in the aging population. Front Aging Neurosci 2011; 3:18. [PMID: 22163221 PMCID: PMC3233724 DOI: 10.3389/fnagi.2011.00018] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 11/21/2011] [Indexed: 11/13/2022] Open
Abstract
While it is well known that skin physiology – and consequently sensitivity to peripheral stimuli – degrades with age, what is less appreciated is that centrally mediated mechanisms allow for maintenance of the same degree of functionality in processing these peripheral inputs and interacting with the external environment. In order to demonstrate this concept, we obtained observations of processing speed, sensitivity (thresholds), discriminative capacity, and adaptation metrics on subjects ranging in age from 18 to 70. The results indicate that although reaction speed and sensory thresholds change with age, discriminative capacity, and adaptation metrics do not. The significance of these findings is that similar metrics of adaptation have been demonstrated to change significantly when the central nervous system (CNS) is compromised. Such compromise has been demonstrated in subject populations with autism, chronic pain, acute NMDA receptor block, concussion, and with tactile–thermal interactions. If the metric of adaptation parallels cortical plasticity, the results of the current study suggest that the CNS in the aging population is still capable of plastic changes, and this cortical plasticity could be the mechanism that compensates for the degradations that are known to naturally occur with age. Thus, these quantitative measures – since they can be obtained efficiently and objectively, and appear to deviate from normative values significantly with systemic cortical alterations – could be useful indicators of cerebral cortical health.
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Affiliation(s)
- Zheng Zhang
- Department of Biomedical Engineering, University of North Carolina Chapel Hill, NC, USA
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10
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de Sousa AA, Reis R, Bento-Torres J, Trévia N, Lins NADA, Passos A, Santos Z, Diniz JAP, Vasconcelos PFDC, Cunningham C, Perry VH, Picanço Diniz CW. Influence of enriched environment on viral encephalitis outcomes: behavioral and neuropathological changes in albino Swiss mice. PLoS One 2011; 6:e15597. [PMID: 21264301 PMCID: PMC3019164 DOI: 10.1371/journal.pone.0015597] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 11/13/2010] [Indexed: 11/25/2022] Open
Abstract
An enriched environment has previously been described as enhancing natural killer cell activity of recognizing and killing virally infected cells. However, the effects of environmental enrichment on behavioral changes in relation to virus clearance and the neuropathology of encephalitis have not been studied in detail. We tested the hypothesis that environmental enrichment leads to less CNS neuroinvasion and/or more rapid viral clearance in association with T cells without neuronal damage. Stereology-based estimates of activated microglia perineuronal nets and neurons in CA3 were correlated with behavioral changes in the Piry rhabdovirus model of encephalitis in the albino Swiss mouse. Two-month-old female mice maintained in impoverished (IE) or enriched environments (EE) for 3 months were behaviorally tested. After the tests, an equal volume of Piry virus (IEPy, EEPy)-infected or normal brain homogenates were nasally instilled. Eight days post-instillation (dpi), when behavioral changes became apparent, brains were fixed and processed to detect viral antigens, activated microglia, perineuronal nets, and T lymphocytes by immuno- or histochemical reactions. At 20 or 40 dpi, the remaining animals were behaviorally tested and processed for the same markers. In IEPy mice, burrowing activity decreased and recovered earlier (8–10 dpi) than open field (20–40 dpi) but remained unaltered in the EEPy group. EEPy mice presented higher T-cell infiltration, less CNS cell infection by the virus and/or faster virus clearance, less microgliosis, and less damage to the extracellular matrix than IEPy. In both EEPy and IEPy animals, CA3 neuronal number remained unaltered. The results suggest that an enriched environment promotes a more effective immune response to clear CNS virus and not at the cost of CNS damage.
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Affiliation(s)
- Aline Andrade de Sousa
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
| | - Renata Reis
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
| | - João Bento-Torres
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
| | - Nonata Trévia
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
| | - Nara Alves de Almeida Lins
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
| | - Aline Passos
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
| | - Zaire Santos
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
| | | | - Pedro Fernando da Costa Vasconcelos
- Instituto Evandro Chagas (IEC), Departamento de Arbovirologia e Febres Hemorrágicas, Ananindeua, Brazil
- Departamento de Patologia, Universidade do Estado do Pará, Belém, Brazil
| | - Colm Cunningham
- School of Biochemistry and Immunology, Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Victor Hugh Perry
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Cristovam Wanderley Picanço Diniz
- Universidade Federal do Pará (UFPA), Instituto de Ciências Biológicas, Laboratório de Investigações em Neurodegeneração e Infecção, Hospital Universitário João de Barros Barreto, Belém, Brazil
- * E-mail:
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Kattenstroth JC, Kolankowska I, Kalisch T, Dinse HR. Superior sensory, motor, and cognitive performance in elderly individuals with multi-year dancing activities. Front Aging Neurosci 2010; 2. [PMID: 20725636 PMCID: PMC2917240 DOI: 10.3389/fnagi.2010.00031] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 07/02/2010] [Indexed: 12/22/2022] Open
Abstract
Aging is associated with a progressive decline of mental and physical abilities. Considering the current demographic changes in many civilizations there is an urgent need for measures permitting an independent lifestyle into old age. The critical role of physical exercise in mediating and maintaining physical and mental fitness is well-acknowledged. Dance, in addition to physical activity, combines emotions, social interaction, sensory stimulation, motor coordination and music, thereby creating enriched environmental conditions for human individuals. Here we demonstrate the impact of multi-year (average 16.5 years) amateur dancing (AD) in a group of elderly subjects (aged 65–84 years) as compared to education-, gender- and aged-matched controls (CG) having no record of dancing or sporting activities. Besides posture and balance parameters, we tested reaction times, motor behavior, tactile and cognitive performance. In each of the different domains investigated, the AD group had a superior performance as compared to the non-dancer CG group. Analysis of individual performance revealed that the best participants of the AD group were not better than individuals of the CG group. Instead, the AD group lacked individuals showing poor performance, which was frequently observed for the CG group. This observation implies that maintaining a regular schedule of dancing into old age can preserve cognitive, motor and perceptual abilities and prevent them from degradation. We conclude that the far-reaching beneficial effects found in the AD group make dance, beyond its ability to facilitate balance and posture, a prime candidate for the preservation of everyday life competence of elderly individuals.
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12
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Lozza FA, Chinchilla LA, Barbeito CG, Goya RG, Gimeno EJ, Portiansky EL. Changes in carbohydrate expression in the cervical spinal cord of rats during aging. Neuropathology 2009; 29:258-62. [DOI: 10.1111/j.1440-1789.2008.00974.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Fontana PA, Barbeito CG, Goya RG, Gimeno EJ, Portiansky EL. Impact of very old age on the expression of cervical spinal cord cell markers in rats. J Chem Neuroanat 2008; 37:98-104. [PMID: 19059476 DOI: 10.1016/j.jchemneu.2008.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 10/31/2008] [Accepted: 11/01/2008] [Indexed: 01/09/2023]
Abstract
Aging is a process associated with both anatomical changes and loss of expression of some cell markers. Intermediate filaments are known to impart mechanical stability to cells and tissues. Some of them are present in different cell populations of the central nervous system. In order to explore the impact of extreme age we immunohistochemically characterized the changes in intermediate filaments and other cellular markers present in cells populating the gray matter cervical spinal cord of very old rats (28 months) taking young (5 months) counterparts as a reference. The spinal cord weight of the senile animals (12.6+/-1.1 g) was significantly higher (P<0.001) than that of the young animals (8.4+/-1.1 g). Spinal cord length also increased significantly (P<0.05) with age (7.9+/-0.3 cm vs. 8.28+/-0.1 cm for young and senile, respectively). An increase in both neurofilament staining area and density was observed in senile rats in comparison to young animals. A significant (P<0.05) age-related increment in the mean area of the cervical segments was observed. Vimentin expression in the ependymal zone decreased in area and intensity during aging. Our data show that there are some significant changes in the morphological and histochemical patterns of the cervical spinal cord in senile rats. However, they do not necessarily represent a pathologic situation and may rather reflect plastic reorganization.
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Affiliation(s)
- Paula Andrea Fontana
- Institute of Pathology, School of Veterinary Sciences, National University of La Plata, La Plata 1900, Argentina
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Abstract
Aging exerts major reorganization and remodeling at all levels of brain structure and function. Studies in aged animals and in human elderly individuals demonstrate that sensorimotor cortical representational maps undergo significant alterations. Because cortical reorganization is paralleled by a decline in perceptual and behavioral performance, this type of cortical remodeling differs from the plastic reorganization observed during learning processes in young individuals where map changes are associated with a gain in performance. It is now clear that brain plasticity is operational into old age; therefore, protocols for interventions such as training, exercising, practicing, and stimulation, which make use of neuroplasticity principles, are effective to ameliorate some forms of cortical and behavioral age-related changes, indicating that aging effects are not irreversible but treatable. However, old individuals cannot be rejuvenated, but restoration of function is possible through the emergence of new processing strategies. This implies that cortical reorganization in the aging brain occurs twice: during aging, and during treatment of age-related changes.
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Affiliation(s)
- Hubert R Dinse
- Institute for Neuroinformatics, Department of Theoretical Biology, Experimental Neurobiology Laboratory, Ruhr-University Bochum, Bochum, Germany.
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Harkany T, Dobszay MB, Cayetanot F, Härtig W, Siegemund T, Aujard F, Mackie K. Redistribution of CB1 cannabinoid receptors during evolution of cholinergic basal forebrain territories and their cortical projection areas: A comparison between the gray mouse lemur (Microcebus murinus, primates) and rat. Neuroscience 2005; 135:595-609. [PMID: 16129564 DOI: 10.1016/j.neuroscience.2005.06.043] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 06/10/2005] [Accepted: 06/14/2005] [Indexed: 11/30/2022]
Abstract
Endocannabinoid signaling, mediated by presynaptic CB1 cannabinoid receptors on neurons, is fundamental for the maintenance of synaptic plasticity by modulating neurotransmitter release from axon terminals. In the rodent basal forebrain, CB1 cannabinoid receptor-like immunoreactivity is only harbored by a subpopulation of cholinergic projection neurons. However, endocannabinoid control of cholinergic output from the substantia innominata, coincident target innervation of cholinergic and CB1 cannabinoid receptor-containing afferents, and cholinergic regulation of endocannabinoid synthesis in the hippocampus suggest a significant cholinergic-endocannabinergic interplay. Given the functional importance of the cholinergic modulation of endocannabinoid signaling, here we studied CB1 cannabinoid receptor distribution in cholinergic basal forebrain territories and their cortical projection areas in a prosimian primate, the gray mouse lemur. Perisomatic CB1 cannabinoid receptor immunoreactivity was unequivocally present in non-cholinergic neurons of the olfactory tubercule, and in cholecystokinin-containing interneurons in layers 2/3 of the neocortex. Significantly, CB1 cannabinoid receptor-like immunoreactivity was localized to cholinergic perikarya in the magnocellular basal nucleus. However, cortical cholinergic terminals lacked detectable CB1 cannabinoid receptor levels. A dichotomy of CB1 cannabinoid receptor distribution in frontal (suprasylvian) and parietotemporal (subsylvian) cortices was apparent. In the frontal cortex, CB1 cannabinoid receptor-containing axons concentrated in layers 2/3 and layer 6, while layer 4 and layer 5 were essentially devoid of CB1 cannabinoid receptor immunoreactivity. In contrast, CB1 cannabinoid receptors decorated axons in all layers of the parietotemporal cortex with peak densities in layer 2 and layer 4. In the hippocampus, CB1 cannabinoid receptor-containing terminals concentrated around pyramidal cell somata and proximal dendrites in the CA1-CA3 areas, and granule cell dendrites in the molecular layer of the dentate gyrus. CB1 cannabinoid receptors frequently localized to inhibitory GABAergic terminals while leaving glutamatergic boutons unlabeled. Aging did not affect either the density or layer-specific distribution of CB1 cannabinoid receptor-immunoreactive processes. We concluded that organizing principles of CB1 cannabinoid receptor-containing neurons and their terminal fields within the basal forebrain are evolutionarily conserved between rodents and prosimian primates. In contrast, the areal expansion and cytoarchitectonic differentiation of neocortical subfields in primates is associated with differential cortical patterning of CB1 cannabinoid receptor-containing subcortical and intracortical afferents.
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Affiliation(s)
- T Harkany
- Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Scheeles väg 1:A1, Karolinska Institutet, S-17177 Stockholm, Sweden.
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Hilbig H, Bidmon HJ, Oppermann OT, Remmerbach T. Influence of post-mortem delay and storage temperature on the immunohistochemical detection of antigens in the CNS of mice. ACTA ACUST UNITED AC 2004; 56:159-71. [PMID: 15625785 DOI: 10.1016/j.etp.2004.08.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of this work was to compare the results of histochemical and immunohistochemical methods using mouse brains which were fixed with various post-mortem delays and storage temperatures (at a constant 4 degrees C or 22 degrees C, or at gradually decreasing post-mortem temperatures, mimicking conditions of human corpse). We studied the effects of post-mortem delay on glial fibrillary acidic protein, extracellular matrix components to which Wisteria floribunda agglutinin binds, non-phosphorylated neurofilament H, synaptophysin, calbindin and nitric oxide synthase isoenzymes. At the light microscopic level first signs of post-mortem changes were detectable after 6 h. Glial fibrillary acidic protein was most affected by post-mortem delay since its immunoreactivity increased dramatically with increasing post-mortem delay. N-acetylgalactosamines-beta1 labeled lectin binding sites, calbindin and intraneuronal non-phosphorylated neurofilament H seemed to be stable up to 12 h post-mortem. Storage temperature influenced the NADPH-d activity and the content of synaptophysin immunoreactivity to higher degree than all of the other parameters. We found only marginal differences of alterations comparing neocortex, hippocampus and corpus callosum. Our results indicate that different antigens are affected differently by the ongoing catabolic processes during post-mortem delay.
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Affiliation(s)
- Heidegard Hilbig
- Institute of Anatomy, Leipzig University, 04103 Leipzig, Germany.
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Engineer ND, Percaccio CR, Pandya PK, Moucha R, Rathbun DL, Kilgard MP. Environmental Enrichment Improves Response Strength, Threshold, Selectivity, and Latency of Auditory Cortex Neurons. J Neurophysiol 2004; 92:73-82. [PMID: 15014105 DOI: 10.1152/jn.00059.2004] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Over the last 50 yr, environmental enrichment has been shown to generate more than a dozen changes in brain anatomy. The consequences of these physical changes on information processing have not been well studied. In this study, rats were housed in enriched or standard conditions either prior to or after reaching sexual maturity. Evoked potentials from awake rats and extracellular recordings from anesthetized rats were used to document responses of auditory cortex neurons. This report details several significant, new findings about the influence of housing conditions on the responses of rat auditory cortex neurons. First, enrichment dramatically increases the strength of auditory cortex responses. Tone-evoked potentials of enriched rats, for example, were more than twice the amplitude of rats raised in standard laboratory conditions. Second, cortical responses of both young and adult animals benefit from exposure to an enriched environment and are degraded by exposure to an impoverished environment. Third, housing condition resulted in rapid remodeling of cortical responses in <2 wk. Fourth, recordings made under anesthesia indicate that enrichment increases the number of neurons activated by any sound. This finding shows that the evoked potential plasticity documented in awake rats was not due to differences in behavioral state. Finally, enrichment made primary auditory cortex (A1) neurons more sensitive to quiet sounds, more selective for tone frequency, and altered their response latencies. These experiments provide the first evidence of physiologic changes in auditory cortex processing resulting from generalized environmental enrichment.
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Affiliation(s)
- Navzer D Engineer
- Neuroscience Program, School of Behavioral and Brain Sciences, GR 41, University of Texas at Dallas, Richardson, TX 75083-0688, USA
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