Social disruption alters pain and cognition in an animal model of multiple sclerosis

- Social stress before infection enhanced affective pain during the chronic phase.
- Stress and infection led to impaired memory, and infection led to more CA1 lesions.
- SJL mice showed infection-related motor deficits during the chronic phase of disease.

Although pain and cognitive deficits are widespread and debilitating symptoms of multiple sclerosis (MS), they remain poorly understood. Theiler's murine encephalomyelitis virus (TMEV) infection is an animal model of MS where disease course is exacerbated by prior stressors. Here chronic infection coupled with prior social stress increased pain behavior and impaired hippocampal-dependent memory consolidation during the demyelinating phase of disease in SJL mice. These results suggest that the TMEV model may be useful in investigating pain and cognitive impairments in MS. However, in contrast to prior Balb/cJ studies, stress failed to consistently alter behavioral and physiological indicators of disease course.