Regional differences in accumulation of tritium-labeled norepinephrine, 5-hydroxytryptamine and gamma-aminobutyric acid in brain slices of spider and rhesus monkey

We have examined the uptake of [³H]norepinephrine, [³H]5-hydroxytryptamine, and γ-amino[³H]butyric acid into 11 different regions of the brains of the spider and rhesus monkey. γ-Amino[³H]butyric acid was concentrated to a similar extent by all areas of monkey brain; failing to correlate with the endogenous concentration of the compound. [³H]Norepinephrine showed a regional localization similar to the endogenous catecholamine distribution, but with some differences. [³H]5-Hydroxytryptamine was concentrated by areas rich in endogenous 5-hydroxytryptamine as well as by areas rich in endogenous catecholamines. Although [³H]norepinephrine and [³H]5-hydroxytryptamine showed similar regional accumulations, there were some significant differences which suggest a specific uptake of [³H]5-hydroxytryptamine by serotoninergic neurons and of [³H]norepinephrine by norepinephrine or dopamine-containing nerve endings. The regional pattern of uptake of the 3 compounds studied was similar in the brains of rhesus and spider monkeys.