Cortical serotonin 7, 1D and 1F receptors: Effects of schizophrenia, suicide and antipsychotic drug treatment

Abstract

Abnormalities in serotonergic function are thought to be important in the pathology of schizophrenia. Postmortem CNS studies suggest that levels of serotonin receptors may be altered in the cortex of subjects with schizophrenia. Seeking to expand this hypothesis we have examined the effect of schizophrenia and antipsychotic drug treatments on the levels of cortical serotonin 7, 1D and 1F receptors. There was a significant decrease in the binding of [ 3H]SB 269970 to the serotonin 7 receptor in Brodmann's area 9 from subjects with schizophrenia compared to controls (Mean ± S.E.M.: 8.3 ± 0.76 vs. 11.0 ± 0.64 fmol/mg ETE; p < 0.05) and an increase in the binding of that radioligand in the cortex of rats treated with haloperidol ( p = 0.03). There were no significant differences in [ 3H]sumatriptan binding to the serotonin 1D or serotonin 1F receptor in Brodmann's area 9 from subjects with schizophrenia. There was a significant increase in [ 3H]sumatriptan binding to the serotonin 1D in binding Layer 2 from subjects who had potentially died by suicide that was not present in other binding layers or for the serotonin 1F or serotonin 7 receptors. There was decrease in [ 3H]sumatriptan binding to the serotonin 1D, but not serotonin 1F, receptors across all cortical binding layers in rats treated with haloperidol. These data would be consistent with the hypothesis that decreased levels of serotonin 7 receptors in Brodmann's area 9 may be involved in the pathological processes of schizophrenia and that levels of cortical serotonin 7 and 1D receptors can be affected by antipsychotic drug treatment.