NEW MORPHOLOGICAL AND NEUROPATHOLOGICAL FINDINGS IN SCHIZOPHRENIA - ANEURODEVELOPMENTAL PERSPECTIVE

This article reviews evidence for morphological abnormalities in schiz ophrenia as assessed by brain imaging and neurohistochemical technique s including immunohistochemistry and in situ hybridization. Localized deficits in schizophrenic brain appear in many regions including front al and temporal lobes, anterior cingulate, mediodorsal thalamic nucleu s, and corpus callosum. These areas are interconnected and may provide the basis for a ''psychosis circuitry'' Neuronal disruption of elemen ts in this circuitry may result in a hypothesized dysconnection syndro me. Evidence suggests an alteration in neuronal development related to either genetic and/or environmental factors. Primary and secondary an terograde and retrograde effects may accompany this neurodevelopmental defect and may further alter intrinsic and extrinsic neuronal communi cations. A number of studies are consistent with the second trimester of gestation being a critical period for fetal brain development, espe cially for neuronal migration. Fetal trauma due to environmental insul ts (e.g., influenza) during this trimester may increase the incidence of schizophrenia. Recent advances in the identification of factors tha t modulate neuronal development including axon guidance molecules, neu rotrophins, and programmed cell death genes provide intriguing new are as for potential investigation. Future research may focus on the facto rs controlling neuronal migration and programmed cell death in the sch izophrenic brain. (C) 1995 Wiley-Liss, Inc.