ANNUAL RHYTHMS OF ENERGY BALANCE AND BEHAVIOR

该提案的总体目标是进一步表征日常冬眠的神经内分泌机制，这是一种极端的温度调节形式，旨在帮助动物应对有限的食物供应。我们将探讨睡眠与整体能量平衡和身体脂肪储存的关系。西伯利亚仓鼠（Phodopus sungorus）是所有实验中的模式物种，其每日冬眠的年度节律得到了很好的记录。具体目的包括：1)阐明身体脂肪储存减少与其在睡眠启动中的反馈机制之间的关系；2)瘦素作为代谢信号抑制睡眠启动的作用；3)探讨NPY在睡眠中的作用；间脑机制在日常昏睡发生中的作用关于间脑控制能量平衡和体温调节的生理机制，我们还不太了解。在像西伯利亚仓鼠这样的模型系统中，描述代谢反馈信号和日常麻木之间的相互作用，可以为哺乳动物尤其是人类的这些过程的调节提供重要的见解。更好地了解可逆性低温的机制具有重要的医学意义。在许多类型的大手术中，伴随体温降低的代谢、血流量等可能是非常有益的。目前，我们对西伯利亚仓鼠和其他几种哺乳动物经历低温的机制知之甚少，低温对人类和大多数其他哺乳动物都是致命的。拟议的研究解决了调控生物学的基本问题，从而提供了建立适用于所有哺乳动物的一般原则的机会。

The overall goal of this proposal is to further characterize the neuroendocrine mechanisms that underlie the initiation and expression of daily torpor, an extreme form of temperature regulation that evolved to help animals contend with limited food availability. The relation of torpor to overall energy balance and body fat stores will be explored. Annual rhythms of daily torpor are well documented in the Siberian hamster (Phodopus sungorus), the model species in all experiments. Specific aims include: 1) clarifying the relation between decreases in body fat stores and its feedback mechanisms in the initiation of torpor; 2) characterizing the role of leptin as a metabolic signal inhibiting initiation of torpor; 3) exploring the role of NPY in torpor; 4) determining the role of diencephalic mechanisms in initiation of daily torpor There is much that we still do not understand about the physiological mechanisms underlying the control of energy balance and thermoregulation. Delineating the interaction between metabolic feedback signals and daily torpor in a model system like the Siberian hamster could provide important insights into the regulation of these processes for mammals in general and humans in particular. A better understanding of the mechanisms of reversible hypothermia is of medical import. The reduced metabolism, blood flow, etc. coincident with hypothermia may be very beneficial during many types of major surgery. At this time, we know little of the mechanism that allows Siberian hamsters and several other mammalian species to undergo hypothermia which is lethal to humans and most other mammals. The proposed research addresses fundamental questions in regulatory biology and, thereby, affords the opportunity of establishing general principles applicable to all mammals.