A behavioral version of catecholamine involvement in new learning rewarded by brain stimulation.

Numerous studies in the rat indicate that catecholamines (CA) mediate rewarding properties of self-administered electrical stimulation to the brain. One such property is the learning of new response-reinforcement relationships. In the present experiment, amphetamine which potentiates CA at the synapse produces stereotypical responding but does not interfere with the learning of new response-reinforcement relationships. Apomorphine, which mimics dopamine (DA) at DA receptors, also produces stereotypy and interferes with learning. The results suggest that DA released by stimulation mediates the stereotyped responding seen in intracranial self-stimulation (ICS) but norepinephrine mediates reward of newly learned responses.