AGE-RELATED-CHANGES IN EXCITATORY AMINO-ACID RECEPTORS IN 2 MOUSE STRAINS

The present study examined the binding of [H-3]-L-glutamate to NMDA re ceptors, [H-3]-kainate to kainate receptors, and [H-3]-AMPA to AMPA/qu isqualate receptors in the brains of C57B1 and BALB/c mice as a functi on of increasing age. Significant decreases in binding to NMDA recepto rs occurred with increasing age (3 to 30 months) in a majority of cort ical and hippocampal brain regions from the C57B] and BALB/c strains o f mice. Significant decreases in binding to kainate and AMPA receptors were found in the inner frontal and parietal cortices and stratum lac unosum/moleculare of CA1 in both strains. These regions also exhibited the greatest percent decline in NMDA binding sites with aging. The lo ss of NMDA receptors in the stratum lacunosum/moleculare of CA1 was gr eater in the BALB/c mice than the C57B1 strain. These results demonstr ate that a few brain regions have age-associated reductions in all thr ee ionotropic EAA receptors; however, the NMDA receptor appears to be selectively vulnerable to the aging process throughout much of the cer ebral cortex and hippocampus.