SEROTONIN(2) RECEPTORS AND THE SEROTONIN TRANSPORTER IN THE SCHIZOPHRENIC BRAIN

The binding of [H-3]paroxetine and [H-3]ketanserin to particulate memb ranes from frontal cortex of subjects who had or did not have schizoph renia was measured as was [H-3]paroxetine binding to particulate membr anes from the hippocampus and caudate nucleus. There was no change in either the affinity or density of [H-3]ketanserin binding to membranes from the frontal cortex of subjects who had schizophrenia. Similarly, there was no difference in the density of [H-3]paroxetine binding to membranes from subjects who had or did not have schizophrenia. The aff inity of [H-3]paroxetine binding in the frontal cortex and putamen did not differ in subjects who had schizophrenia. By contrast, there was a significant decrease in the affinity of [H-3]paroxetine binding to t he hippocampal membrane from subjects who had schizophrenia (0.40 +/- 0.06 nM vs 0.26 +/- 0.02 nM; p < 0.05). Furthermore, this difference w as more apparent in the subjects who had schizophrenia and committed s uicide (0.49 +/- 0.09 nM) than it was in those who had schizophrenia b ut did not commit suicide (0.3 +/- 0.09 nM). As [H-3]ketanserin binds to the serotonin(2) receptor our data suggest that this receptor is no t changed in the Brodmann's area 9 of the frontal cortex. By contrast, [H-3]paroxetine binds to the serotonin transporter and therefore our data suggest that the serotonin transporter is altered in the hippocam pus of subjects with schizophrenia.