Hibernation was also a hot…I mean warm…topic at the American Physiology Summit last month in Baltimore, MD.

Thomas Crippen presented research conducted with team members Dr. Dylan Barth, Zac Carlson, Dr. Frank van Breukelen, and Dr. Allyson Hindle at the University of Nevada, Las Vegas. Their study focused on golden-mantled ground squirrels, Callospermophilus lateralis, which are remarkable even among hibernators. These squirrels can enter torpor across a range of environmental temperatures, lowering their body temperature to as little as 4°C and reducing their metabolism to just 1% of normal levels!

By studying these squirrels exposed to different temperatures, the researchers discovered that the most significant changes in gene expression occurred when the animals underwent torpor at relatively warm temperatures (20-25°C). These changes involved genes related to gene silencing, DNA repair and other cellular processes whereas less changes were observed at colder temperatures.

Ana Breit at the Duke Lemur Center investigated how lessons from nature could inform synthetic human hibernation, which would likely need to be induced at warmer temperatures than true hibernating species to avoid freezing people and damaging tissues. Such warmer temperatures may allow organisms to vary the expression of genes and protein synthesis as compared to freezing temperatures when these processes are highly reduced as seen in the squirrels. Some modifications in genes and proteins may be protective where others may be destructive.

To better understand this, Dr. Breit’s research focuses on the hibernation behaviors and physiological changes in fat-tailed dwarf lemurs, Cheirogaleus medius (pictured above). Like the squirrels, these lemurs can undergo torpor in daily temperatures ranging from 12-32°C. The goal is to develop a model for human hibernation using daily temperature cycles that are warm enough to prevent frequent arousals but also cold enough to conserve energy. Understanding how dwarf lemurs manage torpor under such fluctuating temperatures may one day pave the way for breakthroughs in human medicine, space travel, and more.

Source:

2025 American Physiology Summit, Baltimore, MD

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Categories: Comparative Physiology, Environment, Extreme Animals, Hibernation and Hypoxia, Nature's Solutions, Physiology on the Road, Space Physiology

Tags: American Physiological Society, American Physiology Summit, animals, Environment, fitness, health, Lemur, science