The firing rate of central noradrenergic, serotonergic and dopaminergic neurons was recorded in rats anaesthetized with chloral hydrate. The i.v. perfusion of amineptine decreased the frequency of discharge of noradrenergic and dopaminergic neurons but had no effect on serotonergic cells. Quantitatively amineptine was a more potent inhibitor of dopaminergic than of noradrenergic neurons. These experiments in vivo confirm biochemical studies in vitro reporting a selective action of amineptine on dopaminergic systems.