The topographical distribution of putative neurotransmitter amino acids in both 6- and 20-month-old Fischer 344 rats was studied in eight striatal subregions. Tissue levels of glutamate, aspartate, GABA, and taurine in the 20-month-old rats were elevated in virtually all of the anterior striatal subregions examined. In addition, aspartate levels were higher in all dorsomedial subregions, while glutamate and taurine levels were elevated in all lateral and ventrolateral subregions, respectively. Other amino acids such as glutamate, serine, and alanine did not display any specific subregional changes. These findings demonstrate specific striatal subregion changes in neurotransmitter amino acid content as a function of aging. © 1990.