Exploring the Optimal Temperature Conditions for Synthetic Human Hibernation: Insights from Dwarf Lemur Hibernation in Fluctuating Environments

Inducing synthetic hibernation in humans will likely require temperatures warmer than those observed in traditional Holarctic hibernation models. Hibernation at cold temperatures offers the greatest energetic savings but limits homeostatic regulation. Warmer hibernation temperatures may not offer the same energetic benefits but allow for a greater degree of gene expression (transcription) and protein synthesis (translation) not obtainable at lower temperatures, potentially allowing greater homeostatic control but at the cost of energetic savings. We hypothesize that hibernation at fluctuating daily temperatures – warm enough to avoid interbout arousals but cool enough to save energy – could offer an optimal balance for synthetic human hibernation. To test this hypothesis, we are studying hibernation in fat-tailed dwarf lemurs (Cheirogaleus medius). Endemic to Madagascar, dwarf lemurs are the only primates capable of undergoing months-long hibernation and can do so in nests with daily temperature fluctuations between 12°C and 32°C. We are the first research group to replicate this hibernation phenotype in a lab setting, simultaneously measuring skin temperature and metabolic rate throughout the hibernation season, and taking tissue samples at key physiological timepoints (pre- and post- hibernation, interbout arousal, and mid-torpor bout) to analyze transcriptomic and proteomic data. Preliminary results show that lemurs hibernating in fluctuating temperatures (12°C - 32°C) display greater thermal flexibility (p < 0.05) and energetic savings (p < 0.05) than those hibernating at relatively stable, lower temperatures (18°C-22°C). Final analysis of proteomic and transcriptomic data will further reveal the degree of homeostatic regulation between the two groups. Our research will help identify the optimal hibernation conditions for human synthetic hibernation, balancing the tradeoffs between energy efficiency and homeostatic control. The Duke Lemur Center is supported by NSF and private donations. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.