Theiler's murine encephalomyelitis virus infection of C57BL/6 mice results in acute behavioral seizures in 50% of the mice. Treatment of infected mice with minocycline or infection of interleukin (IL)-6-deficient chimeric mice results in a significant decrease in the number of mice developing seizures. However, in those mice that do develop seizures, the pathological changes (neuronal cell loss, inflammation [perivascular cuffing, gliosis, activated microglia/macrophages]), and the numbers of virus infected cells in minocycline-treated or IL-6-deficient chimeric mice are very similar. Therefore, once seizures develop, the pathological changes are consistent regardless of the treatment or genetic background.