Molecular mechanisms regulating seasonal physiology

季节性哺乳动物在一年中经历了巨大的生理变化。它们精确地调节新陈代谢、体重和生殖功能，以在多变的环境中保持能量平衡。生理适应是大脑中基因表达变化的结果，这些基因表达变化是由白天长度的变化通过褪黑激素驱动的，并且控制能量平衡和生殖的关键功能。只是在最近几年，它被证明，甲状腺激素（T3）的下丘脑的可用性是必不可少的光周期反应的鸟类和哺乳动物，但迄今为止知之甚少的机制T3可能触发重新布线的调节中心。季节性哺乳动物在食物短缺时维持能量平衡的最极端措施是表现出麻木。这种精确控制的代谢减退和体温过低被认为是由整合到光周期背景中的代谢信号驱动的，但中枢调节机制在很大程度上是未知的。我们的目标是阐明下丘脑中枢传递环境和营养信号以控制季节性哺乳动物代谢、体温和体重的分子机制级联。了解这些预期的长期变化的能量平衡在季节性哺乳动物的机制是非常有价值的，因为它提供了令人兴奋的机会，以确定新的机制，在调节能量稳态和体重。

Seasonal mammals undergo massive physiological changes over the course of a year. They precisely regulate metabolism, body weight and reproductive functions as appropriate to maintain energy balance in a variable environment. The physiological adaptations are the result of changes in gene expression in the brain that are driven by changes in day length via the hormone melatonin and that control key functions in energy balance and reproduction. Only in recent years has it been shown that thyroid hormone (T3) availability to the hypothalamus is essential for the photoperiodic response of birds and mammals, but to date little is known about the mechanisms T3 may trigger to rewire regulatory centres. The most extreme measure of seasonal mammals to maintain energy balance in times of food shortage is the expression of torpor. This precisely controlled hypometabolism and hypothermia is thought to be driven by metabolic signals that are integrated into a photoperiod background but central regulatory mechanisms are largely unknown. Our goal is to clarify the cascade of molecular mechanisms by which hypothalamic centers relay environmental and nutritional signals to the control of metabolism, body temperature and body weight in seasonal mammals. Understanding the mechanisms underlying these anticipatory long-term changes in energy balance in seasonal mammals is of great value because it offers exciting opportunities to identify novel mechanisms in the regulation of energy homeostasis and body weight.