Brain Adaptative Changes in Mammalian Hibernation

Hibernation is a natural and non-pathological process that allows a wide range of mammalian species to tolerate adverse environments. This state involves periods of reduced body temperature and metabolic rate (called torpor bouts) that can last for 3-4 days, interspersed with short arousal periods of activity and normothermia. During torpor state, profound but reversible changes take place, such as a general temperature decrease, blood flow reduction and an immunologically and metabolically depressed state. Previous studies have demonstrated that, in the brain, periods of torpor are accompanied by a wide range of complex brain adaptive changes that appear to protect the brain from extreme hypoxia and hypothermia. These changes include a decrease in adult neurogenesis, a fragmentation and reduction of the neuronal Golgi apparatus, alterations in dendritic trees including dendritic spine retraction, a decrease in synaptic protein clustering and morphological and functional changes in microglial cells . Despite these changes, hibernating mammals do not display any neuronal damage or permanent memory alterations, and the return to euthermia involves a rapid rebuilding of structures modified during hibernation. Brain adaptation during mammalian hibernation is an intriguing biological phenomena that has received considerable attention during the last years and has direct implications for the study of brain changes in various neurological diseases.

The present Research Topic is aimed to get a deep insight into the knowledge of adaptative changes that the brain of hibernating mammals undergo during the hibernation cycle. Original research articles are preferred for this research topic, although review articles and commentaries will be also considered.