Hypoxia is one of the strongest environmental drivers of cellular and physiological adaptation. Although most mammals are largely intolerant of
hypoxia, some specialized species have evolved mitigative strategies to tolerate hypoxic niches. Among the most
hypoxia-tolerant mammals are naked mole-rats (Heterocephalus glaber), a eusocial species of subterranean rodent native to eastern Africa. In
hypoxia, naked mole-rats maintain consciousness and remain active despite a robust and rapid suppression of metabolic rate, which is mediated by numerous behavioural, physiological and cellular strategies. Conversely,
hypoxia-intolerant mammals and most other
hypoxia-tolerant mammals cannot achieve the same degree of metabolic savings while staying active in
hypoxia and must also increase
oxygen supply to tissues, and/or enter torpor. Intriguingly, recent studies suggest that naked mole-rats share many cellular strategies with non-mammalian vertebrate champions of
anoxia tolerance, including the use of alternative metabolic end-products and potent pH buffering mechanisms to mitigate cellular acidification due to upregulation of anaerobic metabolic pathways, rapid mitochondrial remodelling to favour increased respiratory efficiency, and systemic shifts in energy prioritization to maintain brain function over that of other tissues. Herein, I discuss what is known regarding adaptations of naked mole-rats to a hypoxic lifestyle, and contrast strategies employed by this species to those of
hypoxia-intolerant mammals, closely related African mole-rats, other well-studied
hypoxia-tolerant mammals, and non-mammalian vertebrate champions of
anoxia tolerance. I also discuss the neotenic theory of
hypoxia tolerance - a leading theory that may explain the evolutionary origins of
hypoxia tolerance in mammals - and highlight promising but underexplored avenues of
hypoxia-related research in this fascinating model organism.