Age and neurochemical correlates of radial maze performance in rats.
Young adult (8 months) and aged (26 months) female Wister rats were tested in a 12-arm radial maze in which the optimal strategy was to enter all arms without a repetition. In order to determine if possible age-associated alterations in behavior were correlated with defects in cholinergic. GABAergic and adrenergic neurons in the hippocampus and cerebral cortex, the activities of choline acetyltransferase (CAT), glutamic acid decarboxylase (GAD) and tyrosine hydroxylase (TH) were assayed in these regions of all animals after testing in the radial maze. In the maze, the aged rats continued to perform at the chance level after 15 trials, whereas the young rats had virtually mastered the task. The only significant neurochemical age effect was an increase in hippocampal TH. However, analysis of individual differences among rats revealed positive correlations between maze performance and hippocampal CAT in the aged group and cortical GAD in both the young and aged groups.
D000375:Aging; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002540:Cerebral Cortex / Q000201:enzymology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004193:Discrimination Learning / Q000502:physiology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000378:metabolism; D006624:Hippocampus / Q000201:enzymology; D011939:Mental Recall / Q000502:physiology; D018377:Neurotransmitter Agents / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D051381:Rats; D013028:Space Perception / Q000502:physiology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D018377:Neurotransmitter Agents; D014446:Tyrosine 3-Monooxygenase; D002795:Choline O-Acetyltransferase; D005968:Glutamate Decarboxylase