Role of various amino acids on the modulation of dopamine release from nigro-striatal dopaminergic neurones

Abstract

The effects of various transmitter amino-acids on the striatal release of 3H-dopamine (3H-DA) were investigated both in vivo in cat and in vitro in rat striatal slices. When applied to the substantia nigra of the anaesthetized cat by means of a push-pull cannula, GABA induced an increase followed by a transient decrease of 3H-DA release in the ipsilateral caudate nucleus; glycine reduced 3H-DA release under similar experimental conditions. When added to the superfusion medium of rat striatal slices, GABA, glutamate and glycine increased the release of the newly synthetized 3H-DA, suggesting that these amino-acids are also directly or indirectly involved in the presynaptic modulation of striatal DA release.