Evidence that the stimulatory effect of neurotensin on dopamine release in rat nucleus accumbens slices is independent of dopamine D 2-receptor activation

Abstract

Neurotensin (NT, 10 −9 M and 10 −7 M) increased the electrically stimulated release of [ 3H]dopamine (DA) in rat nucleus accumbens slices. This effect was not altered by activation of DA D 2-receptors with high or low concentrations of quinpirole (10 −6 M and 10 −8 M) or blockade of DA D 2-receptors with near maximal concentrations of sulpiride (10 −6 M and 10 −5 M). The sulpiride-mediated increase in [ 3H]DA release and the release induced by NT were additive. These results suggest that NT functions independently of DA D 2-receptor activation to modulate DA release in the nucleus accumbens. NT did not modulate the simultaneous release of [ 14C]acetylcholine.