CHANGES IN THE SEROTONIN TRANSPORTER IN THE HIPPOCAMPUS OF SUBJECTS WITH SCHIZOPHRENIA IDENTIFIED USING [H-3] PAROXETINE

[H-3]paroxetine binding to membrane from hippocampus, obtained at auto psy, from 24 schizophrenic and 24 non-schizophrenic subjects has been measured. The affinity of [H-3]paroxetine binding to hippocampal membr ane was decreased in subjects with schizophrenia (Kd = 0.50 +/- 0.04 v s. 0.24 +/- 0.02nM; mean +/- S.E.M. p < 0.001) but was not different i n schizophrenic subjects who had or had not committed suicide (Kd = 0. 50 +/- 0.07 vs. 0.50 +/- 0.04nM). The density of [H-3]paroxetine bindi ng sites did not differ between the schizophrenic and non-schizophreni c subjects. For the schizophrenic subjects, there was no relationship between ante-mortem neuroleptic drug treatment and [H-3]paroxetine bin ding to the hippocampal membrane. Finally, this study has shown that n euroleptic drug treatment of rats does not alter [H-3]paroxetine bindi ng to the hippocampal membranes. Thus, it would seem that the changes in the affinity of [H-3]paroxetine binding to the hippocampus of schiz ophrenic subjects are not likely to be due to neuroleptic drug treatme nt but may be involved in the pathology of the illness.