Serotonin 5-HT₃ receptors in schizophrenia: a postmortem study of the amygdala

Alterations in density of some serotonin receptor sites (5-HT_1A receptors, 5-HT₂ receptors and 5-HT uptake sites) have been reported in postmortem studies of brain obtained from subjects with schizophrenia, suggesting a disturbance in serotonergic transmission in schizophrenia. The purpose of the present study is to investigate [³H]-LY278584 binding to serotonin 5-HT₃ receptors in postmortem samples of amygdala from schizophrenic and matched control subjects. As all of the schizophrenic patients but none of the controls had been treated with neuroleptics, we first investigated in rodents the effects of short-term and long-term haloperidol administration on limbic 5-HT₃ receptors, and we found no effects. No differences in the maximum number of 5-HT₃ binding sites (B_max) or equilibrium dissociation constant (K_d) between schizophrenics and controls were found in amygdala. This study does not support the presence of an alteration of 5-HT₃ receptors in amygdala in schizophrenic patients.