UNCHANGED EXOCYTOTIC RELEASE OF GLUTAMIC-ACID IN CORTEX AND NEOSTRIATUM OF THE RAT DURING AGING

The Ca2+-dependent release of glutamate induced by 4-aminopyridine in synaptosomes prepared both from the cerebral cortex and basal ganglia was unchanged in aged rats (27-30 months) when compared to adults rats (3 months). Consistent with the absence of changes in glutamate exocy tosis during aging, the rise in the cytosolic free Ca2+ concentration, [Ca2+]c, induced by depolarization in synaptosomes from aged rats was similar to that found in control adult rats. The results suggest that during aging the nerve terminals from the cerebral cortex and basal g anglia maintain an intact ability to release glutamate by exocytosis.