Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats
Synaptic response size in the CA1 region of the hippocampus in aged rats is reduced for a given stimulus intensity, compared with that elicited in young rats. Consistent with the in vitro findings of reduced Schaffer collateral-evoked CA1 EPSPs in old rats, the population currents evoked to iontopho...
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| Format: | Article |
| Language: | English |
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Wiley
2000-01-01
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| Series: | Neural Plasticity |
| Online Access: | http://dx.doi.org/10.1155/NP.2000.167 |
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| _version_ | 1841524621815316480 |
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| author | C. A. Barnes G. Rao G. Orr |
| author_facet | C. A. Barnes G. Rao G. Orr |
| author_sort | C. A. Barnes |
| collection | DOAJ |
| description | Synaptic response size in the CA1 region of
the hippocampus in aged rats is reduced for a
given stimulus intensity, compared with that
elicited in young rats. Consistent with the in vitro
findings of reduced Schaffer collateral-evoked
CA1 EPSPs in old rats, the population currents
evoked to iontophoretically applied AMPA are
also smaller relative to the presynaptic fiber
potential amplitude. On the other hand, the size of
the presynaptic fiber potential and amplitude of
unitary intra-cellularly recorded EPSP responses
do not change across age in the CA1 region. These
electrophysiological findings are consistent with
the hypothesis that old rats have fewer functional
synaptic contacts per Schaffer collateral axon
than do young rats. The possibility that this age
change arises as a result of a differential tissue
recovery response to in vitro preparation was
examined in the present study. CA1 presynaptic
fiber potential and EPSP amplitudes evoked by
the stimulation of Schaffer collateral afferents
were studied in intact, freely behaving young
and old rats. We confirmed in vivo the pattern of electrophysiophysiological results previously
reported in vitro and found significant
correlations between the synaptic response
amplitudes and the accuracy of spatial behavior
in the Morris swim task. The data suggest that
changes in functional connectivity of old rats
may be a significant contributor to cognitive
changes during aging. |
| format | Article |
| id | doaj-art-5a360bb87b56443f8810b17b5cad1072 |
| institution | Kabale University |
| issn | 2090-5904 1687-5443 |
| language | English |
| publishDate | 2000-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Neural Plasticity |
| spelling | doaj-art-5a360bb87b56443f8810b17b5cad10722025-02-03T05:47:50ZengWileyNeural Plasticity2090-59041687-54432000-01-017316717810.1155/NP.2000.167Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving RatsC. A. Barnes0G. Rao1G. Orr2Arizona Research Laboratories, Division of Neural Systems, Memory and Aging and the Department of Psychology, University of Arizona, Tucson 85274, AZ, USAArizona Research Laboratories, Division of Neural Systems, Memory and Aging and the Department of Psychology, University of Arizona, Tucson 85274, AZ, USAArizona Research Laboratories, Division of Neural Systems, Memory and Aging and the Department of Psychology, University of Arizona, Tucson 85274, AZ, USASynaptic response size in the CA1 region of the hippocampus in aged rats is reduced for a given stimulus intensity, compared with that elicited in young rats. Consistent with the in vitro findings of reduced Schaffer collateral-evoked CA1 EPSPs in old rats, the population currents evoked to iontophoretically applied AMPA are also smaller relative to the presynaptic fiber potential amplitude. On the other hand, the size of the presynaptic fiber potential and amplitude of unitary intra-cellularly recorded EPSP responses do not change across age in the CA1 region. These electrophysiological findings are consistent with the hypothesis that old rats have fewer functional synaptic contacts per Schaffer collateral axon than do young rats. The possibility that this age change arises as a result of a differential tissue recovery response to in vitro preparation was examined in the present study. CA1 presynaptic fiber potential and EPSP amplitudes evoked by the stimulation of Schaffer collateral afferents were studied in intact, freely behaving young and old rats. We confirmed in vivo the pattern of electrophysiophysiological results previously reported in vitro and found significant correlations between the synaptic response amplitudes and the accuracy of spatial behavior in the Morris swim task. The data suggest that changes in functional connectivity of old rats may be a significant contributor to cognitive changes during aging.http://dx.doi.org/10.1155/NP.2000.167 |
| spellingShingle | C. A. Barnes G. Rao G. Orr Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats Neural Plasticity |
| title | Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats |
| title_full | Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats |
| title_fullStr | Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats |
| title_full_unstemmed | Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats |
| title_short | Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats |
| title_sort | age related decrease in the schaffer collateral evoked epsp in awake freely behaving rats |
| url | http://dx.doi.org/10.1155/NP.2000.167 |
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