Decreased muscarinic1 receptors in the dorsolateral prefrontal cortex of subjects with schizophrenia

Abstract

To test the hypothesis that muscarinic receptors are involved in the pathology of schizophrenia, we measured muscarinic1 (M1R) and muscarinic4 (M4R) protein and mRNA as well as [3H]pirenzepine binding in Brodmann's areas (BA) 9 and 40 obtained postmortem from 20 schizophrenic and 20 age/sex-matched control subjects. There was a significant decrease in [3H]pirenzepine binding to BA 9 (mean ± SEM: 151 ± 15 vs 195 ± 10 fmol mg-1 ETE; P < 0.02), but not BA 40 (143 ± 13 vs 166 ± 11 fmol mg-1 ETE), from subjects with schizophrenia. The level of M1R protein (0.11 ± 0.007 vs 0.15 ± 0.008 OD; P < 0.01), but not M4R protein, was decreased in BA9 from schizophrenic subjects with neither receptor protei..