Grant: Chair: CIHR Sex and Gender Science Chair - Musculoskeletal Health and Arthritis

A large literature in mice and rats documents the existence of sex differences in pain, which parallels known sex differences in humans. The existing animal studies are flawed, however, in a number of ways, and especially because of the practical realities of behavioural testing in animals. In pain experiments--like those in other fields--animals are removed from their home cages for testing, often for the first time ever, and thus experience very high levels of stress, which is well known to affect pain. To avoid this problem, we will house and test mice within a semi-naturalistic enclosure (an Eco-HAB), in which their position is automatically recorded and video cameras capture behaviours without any direct experimenter involvement. This setup will be used to test a number of hypotheses regarding sex differences in pain, including: 1) the frequency and duration of chronic pain behaviours in male and female mice, 2) the social impact of chronic pain in male and female mice, 3) pain-related huddling and allogrooming in mice of both sexes lacking a newly found type of sensory fiber mediating rewarding touch, and 4) the effect of chronic pain on lifespan in male and female mice. The data to be collected may have broad impact not only on our understanding of sex differences in pain and fatigue, but on preclinical research more generally.