The Physiological Basis of Hibernation in Mammals

Abstract

Hibernation is a complicated physiological adaptation that allows mammals, especially those living in temperate and polar regions, to survive for extended periods of time when food is few and the environment is harsh. In order to store energy reserves for the winter, animals enter a state of deep metabolic suppression known as hibernation. This state is characterized by a synchronized decrease in body temperature, heart rate, respiration rate, and total energy expenditure. Complex molecular, cellular, and systemic regulatory mechanisms underpin hibernation's physiological basis. These mechanisms include changes in metabolic fuel utilization from carbohydrates to lipids, modulation of mitochondrial function, and suppression of non-essential physiological processes. The hypothalamus, thyroid hormones, and melatonin are all important neuroendocrine regulators that help start and keep torpor states going. The underlying causes of periodic arousals, which are necessary for the maintenance of brain and immunological functions and are characterized by the transient restoration of euthermic circumstances, are only partially understood. In order to prevent tissue damage during cycles of hypothermia and rewarming, hibernation entails reversible changes in gene expression, protein synthesis, and neuroprotection. This finding has important biological implications for organ preservation, hypothermia therapy, and space travel. examines the physiological processes that cause mammals to hibernate, delves into the adaptive value of this phenomenon, and discusses new viewpoints on how it relates to human health and biomedical advancements.