RELEASE OF NEWLY SYNTHESIZED DOPAMINE FROM DOPAMINE-CONTAINING TERMINALS IN THE STRIATUM OF THE RAT

Abstract
The extraneuronal spontaneous efflux of (3)H-dopamine synthesized endogenously in dopamine terminals has been demonstrated in vitro, by collecting the (3)H amine in superfusates of isolated striatum of the rat previously incubated with (3)H-tyrosine. The (3)H-dopamine newly synthesized appears to be preferentially released. Furthermore, amphetamine and a monoamine oxidase inhibitor (Carton) markedly increased the release of (3)H-dopamine. This effect was also observed with substances normally contained in some striatal neurons: acetylcholine and 5-hydroxytryptamine.