[Neuroleptics and serotonin].

To date, there is no doubt that dopamine plays a key role in the behavioural disorders associated with schizophrenia. However, dopamine is not the only neurotransmitter involved in this syndrome, as it interacts with many neuronal systems in brain. Of special interest is the interaction between dopaminergic and serotoninergic systems with evidence from pharmacological data in animals that each of these systems may exert an inhibitory influence on the other. Furthermore, the psychotomimetic effects of drugs affecting serotoninergic neurotransmission such as LSD, psilocybin, N,N-dimethyltryptamine and 5-methoxy-N,N-dimethyltryptamine also contributed to draw attention onto a possible involvement of serotoninergic systems in at least some of the disorders typical of schizophrenia. This idea received strong support from recent studies on the multiple receptors for serotonin in the central nervous system. These studies not only demonstrate the existence of several classes of serotonin receptors called 5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT2, 5-HT3 and 5-HT4, but led also to the development of novel agonists and antagonists for the stimulation or blockade of each of them. Pharmacological investigations with these ligands revealed that serotonin is probably involved in the behavioural disorders associated with schizophrenia through its binding to three distinct classes of receptors: 5-HT1A, 5-HT2 (or the closely related class 5-HT1C) and 5-HT3.(ABSTRACT TRUNCATED AT250 WORDS)