Neuropeptides in dopamine-containing regions of the brain.

This paper reviews evidence of direct interactions occurring in the central nervous system between peptide- and dopamine-containing neural networks. While it seems fairly clear that neuropeptides are involved in the process of interneuronal communication, their specific role appears to be different from that of classic transmitters (which include dopamine). Neuropeptides coexist with dopamine in specific dopamine-containing neurons; in addition they interact abundantly with the dopaminergic neurons, by acting either on the perikarya or on the dopaminergic nerve terminals. Such interactions are reciprocal and account for some behavioral correlates of neuropeptide and dopamine alterations in the brain. They also shed new light on the pathophysiology of neurological and psychiatric diseases associated with depletion or abundance of brain peptides.