The effects of restraint stress on the neuropathogenesis of Theiler's virus infection: I. Acute disease

Restraint stress was found to have a profound effect on the acute phase of Theiler's virus infection. Increased mortality rates were observed in restr ained CBA mice infected with the BeAn strain of Theiler's virus. In additio n, restrained mice developed higher CNS viral titers than infected/nonrestr ained mice. Thymic atrophy was observed in both infected and uninfected res trained mice. Decreased microgliosis, perivascular cuffing, and astrocytosi s were observed in restrained mice compared to nonrestrained infected mice at 7 days postinfection. Restraint-stressed mice also developed decreased n umbers of lymphocytes and increased numbers of neutrophils in the blood. Th e mechanism proposed for these alterations involves stress-induced corticos terone, which causes immunosuppression, decreased trafficking of inflammato ry cells in the CNS, and, consequently, increased viral replication. (C) 20 01 Academic Press.