NEURODEVELOPMENTAL INSULTS AND SCHIZOPHRENIA

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DESCRIPTION (adapted from applicant's abstract): The overall objective of the proposed research plan is a test of the neurodevelopmental hypothesis of schizophrenia. Diverse evidence suggests that schizophrenia has a neurodevelopmental component of unknown etiology in which injury to the brain occurs during early development. Epidemiologic studies indicate that human offspring exposed to developmental insults such as nutritional deficiencies, viral infection, obstetric complications, and stress are at higher risk for subsequent development of schizophrenia. Brain pathology which might be linked to the neurodevelopmental insults includes abnormal biochemistry as measured by proton (1H) magnetic resonance spectroscopy (MRS). The investigator proposes to link these biochemical abnormalities with the early life stress diathesis of schizophrenia by assessing whether the MRS findings in schizophrenia can be reproduced by early developmental insults in rats. The general design of the proposal includes the use of in vitro 1H MRS to characterize the effects of perinatal stress on the brain regional concentration of N-acetyl-aspartate (NAA) and myoinositol (MI). Behavioral, neuroendocrine, and neurochemical characteristics of perinatal stress would also be defined. Determinations would be conducted at 4 developmental time-points spanning 30-360 days of age and in 8 brain regions. In experiment I, the investigator proposes a characterization of the effects of prenatal stress in the form of repeated daily physical restraint of pregnant dams. Pups born from stressed or non-stressed moms will be cross-fostered at birth and reared by prenatally stressed or normal moms to yield four experimental groups. Experiment II would characterize the effect of postnatal stress in the form of maternal deprivation. Four experimental groups would be used to characterize the interaction of the prenatal stressor with the postnatal stress resulting from rearing by stressed versus non-stressed moms and maternally deprived versus normally reared animals. The investigator provides preliminary evidence that adult male offspring subjected to stress perinatally demonstrate decreased NAA in the left frontal cortex. The proposal would determine when during development this NAA change appears and if it is progressive in nature. The relationship among NAA concentration, and behavioral, neuroendocrine, and neurochemical measures of stress response would also be determined. The results of the proposed studies should provide basic information on potential links between the neurodevelopmental abnormalities and anomalies in adult neurochemistry defined by 1H MRS in schizophrenia.