GENE-EXPRESSION AND NEURONAL-ACTIVITY IN SCHIZOPHRENIA - A STUDY OF POLYADENYLATED MESSENGER-RNA IN THE HIPPOCAMPAL-FORMATION AND CEREBRAL-CORTEX

The abundance of polyadenylated messenger RNA (poly(A)(+)mRNA) reflect s overall gene expression and provides an index of neuronal activity. Poly(A)(+)mRNA was measured in the hippocampal formation and in occipi tal, temporal, cingulate and frontal cortices (Brodmann areas 17, 22, 24 and 46, respectively) of 11 schizophrenic and 17 control subjects p ost mortem by in situ hybridization histochemistry with a S-35-oligode oxythymidine probe. There were no differences in poly(A)(+)mRNA betwee n cases and controls, except fbr a modest decrease in the parahippocam pal gyrus of the schizophrenics which may be attributable to cytoarchi tectural differences in this area in the disease. The unchanged level of poly(A)(+)mRNA in all other regions argues against the existence of a widespread or sustained alteration in the metabolic activity of cor tical neurons in schizophrenia. It also provides a further indication that the differential expression of individual transcripts reported in the disease is not merely reflecting changes in overall gene expressi on. (C) 1997 Elsevier Science B.V.