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Computational epidemiology study of homeostatic compensation during sensorimotor aging. Neural Netw 2021; 146:316-333. [PMID: 34923219 DOI: 10.1016/j.neunet.2021.11.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 10/26/2021] [Accepted: 11/24/2021] [Indexed: 11/20/2022]
Abstract
The vestibulo-ocular reflex (VOR) stabilizes vision during head motion. Age-related changes of vestibular neuroanatomical properties predict a linear decay of VOR function. Nonetheless, human epidemiological data show a stable VOR function across the life span. In this study, we model cerebellum-dependent VOR adaptation to relate structural and functional changes throughout aging. We consider three neurosynaptic factors that may codetermine VOR adaptation during aging: the electrical coupling of inferior olive neurons, the long-term spike timing-dependent plasticity at parallel fiber - Purkinje cell synapses and mossy fiber - medial vestibular nuclei synapses, and the intrinsic plasticity of Purkinje cell synapses Our cross-sectional aging analyses suggest that long-term plasticity acts as a global homeostatic mechanism that underpins the stable temporal profile of VOR function. The results also suggest that the intrinsic plasticity of Purkinje cell synapses operates as a local homeostatic mechanism that further sustains the VOR at older ages. Importantly, the computational epidemiology approach presented in this study allows discrepancies among human cross-sectional studies to be understood in terms of interindividual variability in older individuals. Finally, our longitudinal aging simulations show that the amount of residual fibers coding for the peak and trough of the VOR cycle constitutes a predictive hallmark of VOR trajectories over a lifetime.
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Wille M, Schümann A, Wree A, Kreutzer M, Glocker MO, Mutzbauer G, Schmitt O. The Proteome Profiles of the Cerebellum of Juvenile, Adult and Aged Rats--An Ontogenetic Study. Int J Mol Sci 2015; 16:21454-85. [PMID: 26370973 PMCID: PMC4613263 DOI: 10.3390/ijms160921454] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/04/2015] [Accepted: 08/25/2015] [Indexed: 11/16/2022] Open
Abstract
In this study, we searched for proteins that change their expression in the cerebellum (Ce) of rats during ontogenesis. This study focuses on the question of whether specific proteins exist which are differentially expressed with regard to postnatal stages of development. A better characterization of the microenvironment and its development may result from these study findings. A differential two-dimensional polyacrylamide gel electrophoresis (2DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis of the samples revealed that the number of proteins of the functional classes differed depending on the developmental stages. Especially members of the functional classes of biosynthesis, regulatory proteins, chaperones and structural proteins show the highest differential expression within the analyzed stages of development. Therefore, members of these functional protein groups seem to be involved in the development and differentiation of the Ce within the analyzed development stages. In this study, changes in the expression of proteins in the Ce at different postnatal developmental stages (postnatal days (P) 7, 90, and 637) could be observed. At the same time, an identification of proteins which are involved in cell migration and differentiation was possible. Especially proteins involved in processes of the biosynthesis and regulation, the dynamic organization of the cytoskeleton as well as chaperones showed a high amount of differentially expressed proteins between the analyzed dates.
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Affiliation(s)
- Michael Wille
- Department of Anatomy, Gertrudenstr. 9, 18055 Rostock, Germany.
| | - Antje Schümann
- Department of Anatomy, Gertrudenstr. 9, 18055 Rostock, Germany.
| | - Andreas Wree
- Department of Anatomy, Gertrudenstr. 9, 18055 Rostock, Germany.
| | - Michael Kreutzer
- Proteome Center Rostock, Schillingallee 69, 18055 Rostock, Germany.
| | | | - Grit Mutzbauer
- Department of Pathology, Josef-Schneider-Str. 2, 97080 Würzburg, Germany.
| | - Oliver Schmitt
- Department of Anatomy, Gertrudenstr. 9, 18055 Rostock, Germany.
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3
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Dalton BH, Blouin JS, Allen MD, Rice CL, Inglis JT. The altered vestibular-evoked myogenic and whole-body postural responses in old men during standing. Exp Gerontol 2014; 60:120-8. [PMID: 25456846 DOI: 10.1016/j.exger.2014.09.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 08/22/2014] [Accepted: 09/22/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Brian H Dalton
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada; Department of Human Physiology, University of Oregon, Eugene, OR, United States
| | - Jean-Sébastien Blouin
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada; Brain Research Center, University of British Columbia, Vancouver, British Columbia, Canada; Institute for Computing, Information and Cognitive Systems, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Matti D Allen
- Canadian Centre for Activity and Aging, School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
| | - Charles L Rice
- Canadian Centre for Activity and Aging, School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada; Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - J Timothy Inglis
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada; Brain Research Center, University of British Columbia, Vancouver, British Columbia, Canada
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4
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Ferrari F, Gorini A, Villa RF. Energy Metabolism of Synaptosomes from Different Neuronal Systems of Rat Cerebellum During Aging: A Functional Proteomic Characterization. Neurochem Res 2014; 40:172-85. [DOI: 10.1007/s11064-014-1482-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/03/2014] [Accepted: 11/18/2014] [Indexed: 01/06/2023]
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Abstract
Cerebellar Purkinje cells (PCs), the sole output neurons in the cerebellar cortex, play an important role in the cerebellar circuit. PCs appear to be rather sensitive to aging, exhibiting significant changes in both morphology and function during senescence. This article reviews such changes during the normal aging process, including a decrease in the quantity of cells, atrophy in the soma, retraction in the dendritic arborizations, degeneration in the subcellular organelles, a decline in synapse density, disorder in the neurotransmitter system, and alterations in electrophysiological properties. Although these deteriorative changes occur during aging, compensatory mechanisms exist to counteract the impairments in the aging PCs. The possible neural mechanisms underlying these changes and potential preventive treatments are discussed.
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Platano D, Fattoretti P, Balietti M, Giorgetti B, Casoli T, Di Stefano G, Bertoni-Freddari C, Aicardi G. Synaptic remodeling in hippocampal CA1 region of aged rats correlates with better memory performance in passive avoidance test. Rejuvenation Res 2008; 11:341-8. [PMID: 18442322 DOI: 10.1089/rej.2008.0725] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aging is associated with deficits in long-term declarative memory formation, and wide differences in performance can be observed among aged individuals. The cellular substrates of these deficits and the reasons for such marked individual differences are not yet fully understood. In the present study, morphologic parameters of synapses and synaptic mitochondria in stratum molecolare of CA1 hippocampal region were investigated in aged (26- to 27-month-old) female rats after a single trial inhibitory avoidance task. In this memory protocol animals learn to avoid a dark compartment in which they received a mild, inescapable foot shock. Rats were tested 3 and 6 or 9 hours after the training, divided into good and bad responders according to their performance (retention times above or below 100 seconds, respectively) and immediately sacrificed. The number of synapses and synaptic mitochondria per cubic micrometer of tissue (numeric density), the average area of synapses and volume of synaptic mitochondria, the total area of synapses per cubic micrometer of tissue, the percentage of perforated synapses and the overall volume of mitochondria per cubic micrometer of tissue were evaluated. In the good responder group, the numeric density of synapses and mitochondria was significantly higher and the average mitochondrial volume was significantly smaller 9 hours versus 6 hours after the training. No significant differences were observed among bad responders. Thus, better performances in passive avoidance memory task are correlated with more efficient plastic remodeling of synaptic contacts and mitochondria in hippocampal CA1. Present findings indicate that maintenance of synaptic plastic reactivity during aging is a critical requirement for preserving long-term memory consolidation.
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Affiliation(s)
- Daniela Platano
- Department of Human and General Physiology, University of Bologna, Bologna, Italy
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7
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Thakur MK, Ghosh S. Age and Sex Dependent Alteration in Presenilin Expression in Mouse Cerebral Cortex. Cell Mol Neurobiol 2007; 27:1059-67. [PMID: 17874292 DOI: 10.1007/s10571-007-9214-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 08/31/2007] [Indexed: 01/18/2023]
Abstract
(1) Presenilin (PS) expression is regulated by several cellular and extracellular factors which change with age and sex. Both age and sex are key risk factors for Alzheimer's disease (AD), which is linked to mutations in PS genes. (2) We have analyzed the effect of age and sex on PS expression by northern hybridization and western blot analysis using the cerebral cortex of adult (24 +/- 2 weeks) and old (65 +/- 5 weeks) mice. (3) Our results demonstrate that PS1 was downregulated and PS 2 was upregulated in old mice of both sexes. The level of PS 1 was relatively higher and that of PS 2 was lower in female than male mice of same age group. Taken together, these findings show age and sex dependent alteration in PS expression, which in turn may influence the signal transduction pathways and consequently brain functions.
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Affiliation(s)
- Mahendra Kumar Thakur
- Department of Zoology, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India.
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8
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Sabbatini M, Barili P, Bronzetti E, Zaccheo D, Amenta F. Age-related changes of glial fibrillary acidic protein immunoreactive astrocytes in the rat cerebellar cortex. Mech Ageing Dev 1999; 108:165-72. [PMID: 10400309 DOI: 10.1016/s0047-6374(99)00008-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Age-related changes of glial fibrillary acidic protein (GFAP) immunoreactivity were investigated in the cerebellar cortex of young (3 months), adult (12 months) and old (24 months) rats using immunohistochemical techniques associated with image analysis. In young rats, cell bodies of GFAP-immunoreactive astrocytes were found in the white matter and in the granular layer of cerebellar cortex. Radially-oriented branches of astrocytes which are sited in the granular layer were also observed in the molecular layer. The number of GFAP-immunoreactivity astrocytes of white matter was decreased in adult and old rats in comparison with young cohorts, whereas their size increased progressively from 3 to 24 months old. The number and the size of GFAP-immunoreactive astrocytes of the granular layer was similar in young and adult rats. An increased number and size of GFAP-immunoreactive astrocytes was noticeable in old rats in comparison with younger cohorts. The number of radially oriented branches of the molecular layer was the same in the three age groups investigated. The above results indicate that GFAP-immunoreactive astrocytes of rat cerebellar cortex undergo age-related changes. The not homogeneous sensitivity to aging of cerebellar astrocytes suggests that evaluation of changes of different cell populations of cerebellar cortex should represent an important step of research on aging cerebellum.
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Affiliation(s)
- M Sabbatini
- Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Italy
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9
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Ricci A, Mammola CL, Vega JA, Zaccheo D, Amenta F. Density and pattern of dopamine D2-like receptors in the cerebellar cortex of aged rats. Neurobiol Aging 1996; 17:45-52. [PMID: 8786802 DOI: 10.1016/0197-4580(95)02029-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The pharmacological properties and the anatomical localization of dopamine (DA) D2-like receptors were studied in the cerebellum of 3 months, 12 months, and 24 months male Wistar rats using combined radioligand binding and autoradiographic techniques with [3H]-spiroperidol as a ligand. The binding was consistent with the labelling of the DA D3 receptor subtype. The affinity for DA D2-like receptors was similar in the cerebellar cortex of the three animal groups investigated, whereas the density of binding sites (Bmax value) assessed using conventional radioligand binding techniques was reduced as a function of aging. Light microscope autoradiography revealed the localization of binding sites primarily in the molecular layer and to a lesser amount in Purkinje neurons layer. A loss of binding sites was noticeable with aging in the grey matter of the cerebellar cortex. It affected primarily the molecular layer. Analysis of radioligand binding data and light microscope autoradiography suggests that age-related changes of DA D2-like receptors depend in part by structural alterations of cerebellar cortex and in part by modifications in receptor expression.
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Affiliation(s)
- A Ricci
- Dipartimento Scienze Cardiovascolari e Respiratorie, Università La Sapienza, Roma, Italy
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Ricci A, Zaccheo D, Amenta F. Identification of age-related changes of dopamine D1-like receptors in the rat cerebellar cortex. Synapse 1995; 21:37-44. [PMID: 8525460 DOI: 10.1002/syn.890210106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The present study was designed to characterize the pharmacological profile of dopamine D1-like receptors in the rat cerebellar cortex and to assess if these receptor sites undergo age-related changes. Cerebella of young (3 months), adult (12 months), and old (27 months) male Wistar rats were examined by using radioligand binding techniques and light microscope autoradiography. The non-selective dopamine D1-like radioligand [3H]SCH 23390 was specifically bound to sections of rat cerebellum. The findings that dopamine displaced [3H]SCH 23390 binding in the submicromolar range suggest that labelling of a dopamine D5 (or D1B) receptor subtype. The affinity of [3H]SCH 23390 for dopamine D1-like receptors was similar in the cerebellar cortex of the three animal groups investigated, whereas radioligand binding techniques revealed a gradual age-related reduction of the density of binding sites. Light microscope autoradiography showed the localization of [3H]SCH 23390 binding sites primarily in the molecular layer and to a lesser extent in the Purkinje neuron layer of the cerebellar cortex. Aging was accompanied by a loss of [3H]SCH 23390 binding sites affecting mainly the molecular layer. The age-dependent loss of dopamine D1-like receptors is more pronounced if detected with radioligand binding techniques than with light microscope autoradiography. This suggests that the decrease of dopamine D1-like receptors observed in aging rat cerebellar cortex may depend in part on changes in the receptor expression and in part on cortico-cerebellar structural changes.
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Affiliation(s)
- A Ricci
- Dipartimento Scienze Cardiovascolari e Respiratorie, Università La Sapienza, Rome, Italy
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11
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Saito S, Kobayashi S, Ohashi Y, Igarashi M, Komiya Y, Ando S. Decreased synaptic density in aged brains and its prevention by rearing under enriched environment as revealed by synaptophysin contents. J Neurosci Res 1994; 39:57-62. [PMID: 7807593 DOI: 10.1002/jnr.490390108] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Changes in synaptic density in various brain regions were assessed among different age groups of rats maintained in ordinary small cages, as determined by synaptophysin assay. The synaptophysin content in hippocampus decreases as early as in the adult stage. The most remarkable decrement occurs in occipital cortex. In other regions, synaptophysin contents decrease in senescence to 60-77% of the respective peak values during young and adult stages. The other rat group reared under enriched environment in a large cage until 30 months of age was examined for synaptic density, and was revealed to maintain the similar levels as in young, or even higher levels in frontal, temporal, entorhinal cortices and hippocampus. These results indicate that the synaptic density in cerebrum decreases in senescence and this decrease can be prevented by rearing under enriched environment.
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Affiliation(s)
- S Saito
- Department of Membrane Biochemistry, Tokyo Metropolitan Institute of Gerontology, Japan
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12
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Amenta F, Del Valle M, Vega JA, Zaccheo D. Age-related structural changes in the rat cerebellar cortex: effect of choline alfoscerate treatment. Mech Ageing Dev 1991; 61:173-86. [PMID: 1824122 DOI: 10.1016/0047-6374(91)90015-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The influence of ageing and of 3 months choline alfoscerate treatment on age-related microstructural changes in cerebellar cortex was studied in 3-, 12- and 24-month-old male Sprague-Dawley rats. The number of Purkinje and granule neurons, the density of Nissl bodies in the cytoplasm of Purkinje and granule neurons and the density of silver-gold impregnated fibres within molecular and granule cells layers were assessed by neurohistological and neurohistochemical techniques associated with microdensitometry and quantitative image analysis. The number of Purkinje and granule neurons was approximately the same in rats of 3 and 12 months and significantly decreased in 24-month-old animals. The density of Nissl bodies and of fine processes of silver-gold impregnated fibres were greatest in the cerebellar cortex of rats of 12 months of age, followed in descending order by 3- and 24-month-old rats. Both the density of Nissl bodies and of silver-gold impregnated fibres were significantly lower in the cerebellar cortex of the oldest age group considered in comparison with the young and middle age groups. Treatment with choline alfoscerate, a precursor in the biosynthesis of brain phospholipids which increases bioavailability of choline in the nervous tissue, noticeably reduced the loss of Purkinje and granule neurons in rats of 24 months. Moreover, it restored the density of Nissl bodies in the cytoplasm of Purkinje and granule neurons as well as the density of silver-gold stained fibres in the molecular and in the granule cells layers to values not significantly different from those found in rats of 3 months. These findings suggest that choline alfoscerate treatment may be effective in counteracting the age-dependent disarrangement of rat cerebellar cortex. The possible mechanisms of action of the compound on the microstructural changes of cerebellar cortex occurring with age are discussed.
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Affiliation(s)
- F Amenta
- Dipartimento di Sanità Pubblica e Biologia Cellulare, Università Tor Vergata, Roma, Italy
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13
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Pieri C, Marcheselli F, Falasca M, Moroni F, Recchioni R. Food restriction in female Wistar rats, IV. Morphometric parameters of cerebellar synapses. Arch Gerontol Geriatr 1991; 13:161-5. [PMID: 15374426 DOI: 10.1016/0167-4943(91)90058-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/1990] [Revised: 03/12/1991] [Accepted: 04/04/1991] [Indexed: 11/22/2022]
Abstract
The effect of food restriction on morphometric parameters of cerebellar synapses has been evaluated. A decrease in the number and surface density of synapses has been observed comparing 6 and 27-28 month old rats. Food restriction prevented the loss of the number and attenuated the reduction of the surface density of synaptic contacts occurring during aging. Present data support the idea that food restriction delays the appearance of age-related modifications of synaptic structures and may explain the improvement of motoric coordination and performance found in dietary restricted old animals.
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Affiliation(s)
- C Pieri
- Cytology Center, Gerontological Research Department of I.N.R.C.A., via Birarelli 8, 60121 Ancona, Italy
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14
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Abstract
The enzyme 5'-nucleotidase is present in glial and neuronal membranes, and catalyzes the formation of adenosine, which in turn can act as a neuromodulator or neurotransmitter. The present study found marked increases in histochemically demonstrated 5'-nucleotidase activity in most regions of rat brain from young adulthood (3-4 months) to middle age (12-18 months), with smaller or no changes between middle and old age (24-32 months). The aging adult cerebellum showed alterations in the histochemical pattern, with declines in the molecular layer and increases in the Purkinje layer. Both myelin and synaptic plasma membrane fractions from forebrain showed increases in enzyme activity. Assays of various other body tissues suggested that the increases are fairly specific to brain, and thus apparently do not represent a ubiquitous cellular mechanism of aging. Changes in brain 5'-nucleotidase activity during aging probably reflect the increasing number and size of glial cells, and perhaps also affect synaptic transmission through regulation of adenosine.
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Affiliation(s)
- J L Fuchs
- Department of Biological Sciences, University of North Texas, Denton 76203
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15
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Scheff SW, Scott SA, DeKosky ST. Quantitation of synaptic density in the septal nuclei of young and aged Fischer 344 rats. Neurobiol Aging 1991; 12:3-12. [PMID: 2002880 DOI: 10.1016/0197-4580(91)90032-f] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Synaptic density in the medial and lateral septal nuclei was examined in 3 and 24-28 months of age Fischer 344 rats. The lateral nucleus had a higher synaptic density than the medial region in both age groups. There were no statistically significant differences in synapse density in either region as a function of age, but the data suggested a subpopulation of aged animals which did show an age-related decline in synaptic density in the lateral, but not medial area of the septum. These data indicate that sample size may be an important variable in assessing possible age-related differences in synaptic density, since a broad range of values, some significantly below the range of young animals, exists in the aged brain.
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Affiliation(s)
- S W Scheff
- Department of Anatomy, University of Kentucky Medical Center, Lexington 40536-0230
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Topple A, Smith G, Fifkova E, Cullen-Dockstader K. Nuclear pore complex frequency in CA1 pyramidal cells of the aging rat. Mech Ageing Dev 1990; 51:33-9. [PMID: 2299888 DOI: 10.1016/0047-6374(90)90159-d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The frequency and the diameter of nuclear pore complexes, and the nuclear perimeter, were studied in CA1 pyramidal cells of the hippocampi from 3-, 9-, 24-, and 30-month-old rats (Fischer 344). No changes with age in any of these parameters were observed. This finding is discussed in terms of varied responses of different brain areas to the effects of aging.
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Affiliation(s)
- A Topple
- Department of Psychology, University of Colorado, Boulder 80309
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17
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Abstract
Cell loss, changes in synapse morphology, electrophysiologic alterations, and changes in the supporting microenvironment have all been noted in portions of the vestibular systems of aged animals and humans. Increased variability with age is also a prominent finding in many studies. Quantitative vestibular testing in humans has shown alterations with age as well, but decline with aging is not a prominent feature of all measures, and many reported studies are methodogically flawed. The connection between these observed aging changes and the increased incidence of dizziness and falls in the elderly is unproven, however, and clinicians should search carefully for specific disease processes in their elderly patients who present with vestibular symptoms.
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Affiliation(s)
- P D Sloane
- Department of Family Medicine, University of North Carolina, Chapel Hill 27599
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18
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Eriksdotter-Nilsson M, Gerhardt G, Seiger A, Hoffer B, Granholm AC. Multiple changes in noradrenergic mechanisms in the coeruleo-hippocampal pathway during aging. Structural and functional correlates in intraocular double grafts. Neurobiol Aging 1989; 10:117-24. [PMID: 2542818 DOI: 10.1016/0197-4580(89)90020-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Age-related changes of the coeruleo-hippocampal noradrenergic system were investigated using intraocular double transplants. Pieces of fetal hippocampus were grafted into the anterior chamber of the eye and placed into contact with previously inserted locus coeruleus grafts. Ages of both transplants and hosts were varied to enable studies of intrinsic versus extrinsic determinants of aging in an isolated neuronal circuit. Four different experimental groups, with the approximate age in months of grafts/hosts at the time of recording given in parentheses, were studied; young grafts in the eyes of young hosts (3/7), young grafts in the eyes of old hosts (3/23), mature transplants in adult host rats (8/12) and aged transplants in the eyes of aged rats (21/25). Extracellular recordings from the hippocampal part of the double grafts were performed. Superfusion with alpha-adrenergic antagonists and the alpha 2-agonist clonidine elicited significant increases in the discharge rate of the grafted hippocampal neurons in all groups except the aged transplants in the aged hosts (21/25), where a small excitation was elicited with clonidine and no effect at all was seen with alpha-adrenergic antagonists. The host age did not seem to be important since young transplants in the old hosts (3/23) showed a similar increase in discharge rate as transplants in the young and adult hosts. Tyrosine hydroxylase immunohistochemistry and high-performance liquid chromatography revealed that hippocampal transplants remaining in oculo for a minimum of 6-10 months became permanently hyperinnervated by noradrenergic fibers from the locus coeruleus grafts. The density of noradrenergic fibers was significantly lower in young transplants.(ABSTRACT TRUNCATED AT 250 WORDS)
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Bronzetti E, Felici L, Ferrante F, Amenta F. Age-related changes of the metabolic profile of rat cerebellar cortex: enzyme histochemical study. Mech Ageing Dev 1988; 44:277-86. [PMID: 3216724 DOI: 10.1016/0047-6374(88)90028-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The influence of aging on the metabolic profile of cerebellar cortex was studied in young (3-month-old), adult (12-month-old) and aged (26-month-old) male Sprague-Dawley rats using enzyme histochemical techniques. The following enzymatic activities related to energy transduction were examined: lactate-(LDH) and succinate-(SDH) dehydrogenases; NADH2-tetrazolium reductase (NADHD) and alpha-glycerophosphate-dehydrogenase (GPDH). The intensity of enzymatic staining within the neuropil of molecular and granular layers as well as within the cytoplasm of Purkinje neurons of young, adult and aged animals was assessed microphotometrically. In the molecular layer LSH, SDH and NADHD levels were reduced in old rats; GPDH was decreased both in adult and old animals. In Purkinje neurons no age-related changes of the enzymatic activities under study were observed. In the granular layer LDH and GPDH showed an age-dependent loss; SDH and NADHD were unchanged. The possibility that age-related changes of the enzymatic activities under study may be due to impaired energy production mechanisms and/or represent the consequence of reduced energetic needs resulting from the documented age-dependent loss of synapses in the molecular or in the granular layers of cerebellar cortex is discussed.
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Affiliation(s)
- E Bronzetti
- Dipartimento di Scienze Neurologiche, Università La Sapienza, Roma, Italy
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20
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Delay ER, Wenzel DM, Isaac W. Age changes in electrophysiological measures of the superior colliculus and occipital cortex. Physiol Behav 1988; 42:163-6. [PMID: 3368535 DOI: 10.1016/0031-9384(88)90292-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Locomotor activity and electrophysiological recordings of the superior colliculus and the occipital cortex were measured for two age groups of rats (100-105 and 230-235 days old) tested in ambient light and dark sensory conditions. Age differences in response to ambient illumination were observed in both behavioral and electrophysiological data. While no age differences were found for the superior colliculus data, cortical activity of the older rats differed from that found in the younger rats. These results are interpreted in terms of potential cortical development and arousal functions.
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Affiliation(s)
- E R Delay
- Department of Psychology, Regis College, Denver, CO 80221
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