Hypothalamic hormone deficiency enables physiological anorexia in ground squirrels during hibernation.

Mammalian hibernators survive prolonged periods of cold and resource scarcity by temporarily modulating normal physiological functions, but the mechanisms underlying these adaptations are poorly understood. The hibernation cycle of thirteen-lined ground squirrels (Ictidomys tridecemlineatus) lasts for 5-7 months and comprises weeks of hypometabolic, hypothermic torpor interspersed with 24-48-h periods of an active-like interbout arousal (IBA) state. We show that ground squirrels, who endure the entire hibernation season without food, have negligible hunger during IBAs.

Hypothalamic hormone deficiency enables physiological anorexia.

Mammalian hibernators survive prolonged periods of cold and resource scarcity by temporarily modulating normal physiological functions, but the mechanisms underlying these adaptations are poorly understood. The hibernation cycle of thirteen-lined ground squirrels lasts for 5-7 months and comprises weeks of hypometabolic, hypothermic torpor interspersed with 24-48-hour periods of an active-like interbout arousal (IBA) state. We show that ground squirrels, who endure the entire hibernation season without food, have negligible hunger during IBAs.

LINE-1 activation in the cerebellum drives ataxia.

Dysregulation of long interspersed nuclear element 1 (LINE-1, L1), a dominant class of transposable elements in the human genome, has been linked to neurodegenerative diseases, but whether elevated L1 expression is sufficient to cause neurodegeneration has not been directly tested. Here, we show that the cerebellar expression of L1 is significantly elevated in ataxia telangiectasia patients and strongly anti-correlated with the expression of epigenetic silencers. To examine the role of L1 in the disease etiology, we developed an approach for direct targeting of the L1 promoter for overexpression in mice.