November 1991

Hippocampal Neuron Number in SchizophreniaA Stereological Study

Author Affiliations

From the Morphological Brain Research Laboratory, Department of Psychiatry (Drs Heckers and Heinsen and Ms Geiger), and the Department of Psychiatry (Dr Beckmann), University of Würzburg (Federal Republic of Germany). Dr Heckers is now with the Department of Neurology, Harvard Medical School, Beth Israel Hospital, Boston, Mass.

Arch Gen Psychiatry. 1991;48(11):1002-1008. doi:10.1001/archpsyc.1991.01810350042006

• Neuropathologic and neuroradiologic studies have reported hippocampal abnormalities in schizophrenics. We estimated the total number of neurons in the hippocampus of schizophrenics and controls to elucidate the neuronal basis of such changes. Thirteen brains of schizophrenics and 13 control brains closely matched for sex and age were studied. A new stereological method was applied to serial coronal sections through the whole hippocampus. Total hippocampal volume was reduced in the schizophrenic sample, more pronounced on the left side, but mean differences were not significant. The volumes of the pyramidal cell layer in the four subdivisions subiculum and cornu Ammonis sectors CA 1, CA 2/3, and CA 4 were almost identical in both groups. Schizophrenics did not differ from controls with regard to nerve cell density in any of the four subdivisions. The estimates of the total number of neurons in the hippocampal subdivisions were not different between schizophrenics and controls. The data do not support the hypothesis that hippocampal abnormalities are caused by neuronal cell loss. However, they are consistent with the suggestion that white matter changes in the hippocampus may play a role in the pathogenesis of schizophrenia.