Synaptophysin and GAP-43 mRNA levels in the hippocampus of subjects with schizophrenia

Synaptophysin and growth associated protein-43 (GAP-43) are synaptic protei ns colocalized to the presynaptic terminal, and involved in regulating tran smitter release and synaptic plasticity. Recent studies have proposed an al teration in the number of synapses in the brains of individuals with schizo phrenia. As a corollary, we hypothesized that then may be an alteration in the level of mRNAs that code for synaptic proteins in brains of patients wi th schizophrenia. Using in situ hybridization, we investigated the levels o f synaptophysin and GAP-43 mRNA in the medial temporal lobe of 10 normal su bjects, 11 subjects with schizophrenia and 10 psychiatric control subjects. Synaptophysin mRNA levels were significantly reduced in several hippocampa l subfields in both the schizophrenic and psychiatric control groups. GAP-4 3 mRNA levels were not significantly reduced in either group. The implicati ons of these findings are discussed in relation to neuroleptic treatment an d the pathophysiology of mental illness. (C) 2001 Elsevier Science B.V. All rights reserved.