[Involvement of sigma receptors in schizophrenic syndromes. Pathophysiological approach]

Sigma ligands have been identified as psychotomimetic agents unrelated to opioids. A number of neuroleptics possess moderate to high affinity for sigma binding sites, raising the possibility that sigma receptors mediate some of the antipsychotic effects of neuroleptics. In addition, sigma binding sites have been reported to be reduced in the temporal cortex and in the hippocampus of schizophrenic patients. This hypothesis is further supported by the use of the sigma ligands rimcazole, BMY-14802 and remoxipride as effective antipsychotic agents. The present report, reviewing briefly the physiological effects of sigma ligands, suggests that their antipsychotic properties are related to modulation of NMDA receptors. Thus, the use of sigma ligands may provide further understanding of the pathophysiology of psychoses and open new avenues for their treatment.