Hibernation in Dwarf Lemurs

In collaboration with a number of Duke colleagues, we are participating in a study of the fat-tailed dwarf lemur (Cheirogaleus medius). This lemur is unique in that it undergoes deep hibernation for up to 6 months of each year, a feat few other mammals, and no other primate, can achieve.

During hibernation, brain activity is altered, metabolic rate dramatically decreases and temperature regulation ceases. The neurobiologic mechanisms which mediate these drastic changes are yet to be described. Our study has both an active field component in Madagascar, as well as the study of captive dwarf lemurs held at the Duke Lemur Center.

We propose to found a cross-disciplinary research group to evaluate neurophysiologic, endocrinologic, and genetic mechanisms involved in the regulation of hibernation. Our colleagues are studying the neural processes related to REM and Non-REM sleep which appear to be involved in the regulation of body temperature, determining whether it remains constant or reverts to an older, “reptilian" state, where body temperature matches that of the environment. They are also investigating the regulatory function of the thyroid gland which we suspect acts as a transducer of environmental cues. Our lab group aims to investigate the genetic mechanisms which regulate hibernation. At present, we are seeking to discover genes that confer the capacity to reversibly switch from one state to the other as occurs in Cheirogaleus.

By improving the understanding of the neural regulation of hibernation, our study has the potential for identifying new approaches for the treatment of a host of human ailments. By identifying mechanisms for inducing hibernation-like states in humans the proposed research also has relevance to space travel and for developing means to aide human survival in extreme environmental conditions. Further, the proposed research effort has the potential to improve our understanding of the functions of sleep.