Brain stimulation reward: Evidence for an adrenergic contribution in the rat.

Two centrally active inhibitors of phenylethanolamine-N-methyltransferase (PNMT: E.C. 2.1.1.28), the terminal enzyme for epinephrine biosynthesis in the brain, and a centrally active blocker of adrenergic synapses produced dose-related decreases in responding for intracranial reward. These decreases occurred at dosage levels which were free from measurable neurologic impairment. The present findings may indicate a possible role for epinephrine-containing neurons in the control of central reward processes.