CONCOMITANT DEVELOPMENT OF [DOPAMINE-H-3 AND [HYDROXYTRYPTAMINE-H-3-5 UPTAKE SYSTEMS IN RAT-BRAIN REGIONS

Synaptosomal uptake mechanisms of 5‐hydroxytryptamine and dopamine were examined in cerebral cortex, corpus striatum and midbrain plus brainstem of developing rats. In all regions, there was generally a parallel biphasic development of both uptake systems; the most rapid increases occurred in the first two weeks postpartum, followed by a slower rate of increase. Kinetic studies with dopamine indicated that the maturation involved increases in maximal uptake without a change in the substrate Km, suggesting that there is a change in the number of terminals but not in the uptake system per se. 1979 British Pharmacological Society