Behavioral characterization of acute phase of Theiler's Murine Encephalomyelitis virus infection

Abstract

Theiler's Murine Encephalomyelitis virus (TMEV) infection induces a bi-phasic disease with distinct acute and chronic infection patterns. This study characterizes the behavioral markers of disease during the acute phase utilizing behavioral tests to quantify sickness syndrome. Allodynia was exhibited in infected mice on day 1 post infection (pi), reflected by a decrease in von Frey scores from baseline measures. Sucrose preference was decreased on day 0 to 3 pi in infected animals relative to mock-infected vehicle animals and all both groups decreased preference relative to uninfected animals. Body temperature and body weight measures did not conclusively differentiate between infected and mock-infected vehicle animals. Infected animals experienced fever on day 1 and 3 pi, while mock-infected vehicle animals displayed hypothermia on the same days, with temperatures taken at 1 and 3 pm. Infection did not significantly affect fear conditioning nesting, open field locomotor activity, and social interaction. Summarily, mock-infected vehicle animals showed mild sickness behaviors in comparison to the control-uninfected animals, but the infected mice exhibited the highest magnitude of sickness responses. Chronic phase data will be collected in these mice to characterize behavioral manifestations of the demyelinating autoimmune process.