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Glutamate receptor binding in the frontal cortex and dorsal striatum of aged rats with impaired attentional set‐shifting
Author(s) -
Nicolle Michelle M.,
Baxter Mark G.
Publication year - 2003
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2003.03077.x
Subject(s) - kainate receptor , neuroscience , striatum , ampa receptor , ionotropic effect , nmda receptor , glutamate receptor , psychology , anterior cingulate cortex , prefrontal cortex , morris water navigation task , cingulate cortex , chemistry , hippocampal formation , endocrinology , medicine , receptor , central nervous system , biology , dopamine , cognition
Aged Long–Evans rats exhibit deficits in attentional set shifting, an aspect of executive function, relative to adult rats. Impairments in set shifting and spatial learning are uncorrelated in aged rats, indicating a possible dissociation of the effects of ageing in prefrontal versus hippocampal systems. Ionotropic glutamate receptor binding was assessed using an in vitro autoradiography method in young and aged rats. The rats had been tested on a set‐shifting task that measured attentional set shifts and reversal learning, as well as in a spatial learning task in the Morris water maze. [ 3 H]Kainate, [ 3 H]AMPA and NMDA‐displaceable [ 3 H]glutamate receptor binding were quantified in orbital cortex, cingulate cortex, medial frontal cortex, dorsolateral and dorsomedial striatum. Age‐related decreases in [ 3 H]kainate binding were apparent in all regions measured. Similarly, NMDA‐displaceable [ 3 H]glutamate binding was decreased in the aged rats in all the regions measured except for the medial frontal area where no age effects were observed. [ 3 H]AMPA receptor binding was preserved with age in all the regions measured. Lower levels of [ 3 H]kainate binding in the cingulate cortex were significantly correlated with poorer set‐shifting performance, whereas higher levels of NMDA binding in the dorsomedial striatum were correlated with poorer set‐shifting performance. There were no significant correlations between the levels of ionotropic glutamate receptors and performance in the reversal task or spatial learning in the Morris water maze. These results indicate that age‐related behavioural deficits in attentional set shifting are selectively associated with neurobiological alterations in the cingulate cortex and dorsomedial striatum.