Enhanced oxidative capacity of ground squirrel brain mitochondria during hibernation

• DOI: 10.1152/ajpregu.00314.2016
• Publication Date: 2017-01-12T02:10:28Z
• Authors: Mallory A. Ballinger; Christine Schwartz; Matthew T. Andrews
• Keywords: Torpor; Hibernation; Ground squirrel; Bioenergetics

During hibernation, thirteen-lined ground squirrels (Ictidomys tridecemlineatus) regularly cycle between bouts of torpor and interbout arousal (IBA). Most the brain is electrically quiescent during but regains activity quickly upon to IBA, resulting in extreme oscillations energy demand hibernation. We predicted increased functional capacity mitochondria hibernation compared with spring accommodate variable demands To address this hypothesis, we examined mitochondrial bioenergetics squirrel across three time points: (SP), (TOR), IBA. Respiration rates isolated through complex I electron transport chain were more than twofold higher TOR IBA SP (P < 0.05). also found a 10% increase membrane potential 0.05), that proton leak was lower SP. Finally, there 30% calcium loading 0.01). analyze abundance measured ratio copy number gene (ND1) vs. nuclear (B2M) frozen cerebral cortex samples. No significant differences observed DNA copies These data show are not static year suggest function effectively season, allowing for rapid production meet when physiological changes occurring.