Nerve Injuries Induce Systemic Immune Changes in Mice Study

Preclinical research from McGill University suggests that nerve injuries can create long-term changes in the immune system, and these changes may not be the same for males and females. Nerve injuries are common and can occur from stretching, pressure, or cuts, often leading to persistent problems such as chronic pain.

Laboratory analysis of blood from mice showed clear evidence of bodywide inflammation after a nerve injury. In male mice, inflammatory markers in the bloodstream increased and remained elevated. In female mice, those same markers did not rise at all.

However, when blood taken from injured males or females was transferred into healthy mice, it produced increased sensitivity to pain in both cases. According to co-author Jeffrey Mogil, E.P. Taylor Professor of Pain Studies at McGill, this indicates that something in the bloodstream, although different in males and females, is capable of spreading pain responses throughout the body.

Sam Zhou, the study's lead author and a PhD student at McGill, emphasized that understanding how men and women react differently to nerve injuries could lead to more personalized and effective treatments for chronic pain.

The researchers report that nerve injuries may influence much more than the damaged site, with long-lasting disruptions to immune function potentially raising the likelihood of chronic pain and contributing to related conditions such as anxiety and depression.

Dr. Ji Zhang, the senior author and a professor at McGill's Department of Neurology and Neurosurgery, stated that recognizing the full impact of nerve injuries is important for both doctors and patients, noting that a localized nerve injury can affect the whole body and that men and women may respond differently.

The study, titled 'The impact of nerve injury on the immune system across the lifespan is sexually dimorphic,' was published in Neurobiology of Pain and funded by the Canadian Institutes of Health Research and the Louise and Alan Edwards Foundation.