Schizophrenia and viral infection during neurodevelopment: a focus on mechanisms

The task of defining schizophrenia pathogenesis has fascinated and frustrat ed researchers for nearly a century. In recent years, unprecedented advance s from diverse fields of study have given credence to, both, viral. and dev elopmental theories. This review considers possible mechanisms by which; vi ral and developmental processes may interact to engender schizophrenia. Man y of the current, controversies in schizophrenia pathogenesis are reviewed in light of the viral hypothesis, including. epidemiological findings and t he role of a genetic diathesis, phenotype heterogeneity,, abnormalities in excitatory and inhibitory neurotransmitter systems, anomalous cerebral late reralization, and static vs progressive disease. The importance of animal m odels, in elucidating the impact of viral infections on developing neurons is illustrated by recent studies in which: neonatal rats are infected with lymphocytic choriomeningitis virus in order to examine alterations in hippo campal circuitry. Finally, consideration is: given to a new hypothesis that some cases of schizophrenia could be instigated by a viral infection that disrupts developing Inhibitory circuits, consequently unleashing glutamater gic neurotransmission leading to selective excitotoxicity, and a degenerati ve disease course.