Effects of catecholaminergic drugs on systems of reward and punishment in experiments on cats.

Injection of amantadine or DOPA produced inhibition of both self-stimulation and negative-reinforcing effects of stimulation of the hypothalamus. After injections of l-DOPA in cats pretreated with RO 4-4602, an inhibitor of peripheral decarboxylase, or disulfiram, a dopamine-beta-hydroxylase inhibitor, the inhibitory action on the reinforcing system was enhanced. Amphetamine activated both reward and punishment systems. This data supports an inhibitory function of dopamine in systems of reinforcement and of an activating function of noradrenaline in these systems.