Naked mole rats (Heterocephalus glaber) can survive for six hours in extremely low oxygen environments and have the ability to survive without oxygen at all for more than 18 minutes.

The brain cells of other mammals begin to die without oxygen, because oxygen is required in glycolysis (a process that releases energy that fuels cells) to break down the sugar glucose. Naked mole rats also rely on glycolysis, but, when they are placed in oxygen-free conditions, they can switch to a modified pathway that relies on the sugars fructose and sucrose. The animals also have a fructose-transporting molecule called GLUT-5 that shapes fructose in such a way that it can enter glycolysis later on when oxygen is not required. This change allows a naked mole rat to continue to make energy to keep its brain cells alive for a longer time.

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