Regional distribution of glutamate and aspartate in adult and old human brain

In previous studies on rat brain we found that the observed heterogeneity of the regional distribution of amino acids was much greater when small well-defined anatomical structures were assayed. We therefore reinvestigated the distribution of glutamate and aspartate in 50 discrete areas from adult and old human brain. The concentration of glutamate in the area of highest level was 4.5 and 4.7 times as high as in the area of lowest level in adult and old brain respectively; for aspartate these values were 3.0 and 6.6. Several changes in old brain were noted. The human pattern differed from that in rat.