Back to the Womb: A Perinatal Perspective on Mammalian Hibernation

TY - JOUR

T1 - Back to the Womb: A Perinatal Perspective on Mammalian Hibernation

AU - Singer, Dominique

PY - 2023

Y1 - 2023

N2 - AbstractThe idea of putting astronauts into a hibernation-like state during interplanetary spaceflights has sparked new interest in the evolutionary roots of hibernation and torpor. In this context, it should be noted that mammalian fetuses and neonates respond to the environmental challenges in the perinatal period with a number of physiological mechanisms that bear striking similarity to hibernation and torpor. These include three main points: first, prenatal deviation from the overall metabolic size relationship, which adapts the fetus to the low-oxygen conditions in the womb and corresponds to the metabolic reduction during hibernation and estivation; second, intranatal diving bradycardia in response to shortened O2 supply during birth, comparable to the decrease in heart rate preceding the drop in body temperature upon entry into torpor; and third, postnatal onset of nonshivering thermogenesis in the brown adipose tissue, along with the increase in basal metabolic rate up to the level expected from body size, such as during arousal from hibernation. The appearance of hibernation-like adaptations in the perinatal period suggests that, conversely, hibernation and torpor may be composed of mechanisms shared by all mammals around birth. This hypothesis sheds new light on the origins of hibernation and supports its potential accessibility to nonhibernating species, including humans.

AB - AbstractThe idea of putting astronauts into a hibernation-like state during interplanetary spaceflights has sparked new interest in the evolutionary roots of hibernation and torpor. In this context, it should be noted that mammalian fetuses and neonates respond to the environmental challenges in the perinatal period with a number of physiological mechanisms that bear striking similarity to hibernation and torpor. These include three main points: first, prenatal deviation from the overall metabolic size relationship, which adapts the fetus to the low-oxygen conditions in the womb and corresponds to the metabolic reduction during hibernation and estivation; second, intranatal diving bradycardia in response to shortened O2 supply during birth, comparable to the decrease in heart rate preceding the drop in body temperature upon entry into torpor; and third, postnatal onset of nonshivering thermogenesis in the brown adipose tissue, along with the increase in basal metabolic rate up to the level expected from body size, such as during arousal from hibernation. The appearance of hibernation-like adaptations in the perinatal period suggests that, conversely, hibernation and torpor may be composed of mechanisms shared by all mammals around birth. This hypothesis sheds new light on the origins of hibernation and supports its potential accessibility to nonhibernating species, including humans.

KW - Humans

KW - Animals

KW - Female

KW - Hibernation/physiology

KW - Mammals/physiology

KW - Torpor

KW - Body Temperature

KW - Uterus

U2 - 10.1086/722905

DO - 10.1086/722905

M3 - SCORING: Review article

C2 - 36921266

VL - 96

SP - 153

EP - 165

JO - PHYSIOL BIOCHEM ZOOL

JF - PHYSIOL BIOCHEM ZOOL

SN - 1522-2152

IS - 2

ER -