ANNUAL RHYTHMS OF ENERGY BALANCE AND BEHAVIOR

这项建议的总体目标是进一步描述日常麻木的神经内分泌机制，日常麻木是一种极端的温度调节形式，进化成帮助动物应对有限的食物供应。麻木与整体能量平衡和身体脂肪储存的关系将被探讨。在所有实验的模式物种西伯利亚仓鼠中，每日麻木的年度节律被很好地记录下来。具体目标包括：1)阐明体内脂肪储备减少及其反馈机制与麻木起始的关系；2)确定瘦素作为抑制麻木起始的代谢信号的作用；3)探讨NPY在麻木起始中的作用；4)确定间脑机制在日常麻木起始中的作用。关于控制能量平衡和体温调节的生理机制，我们仍有许多不清楚的地方。在西伯利亚仓鼠这样的模型系统中描绘代谢反馈信号与日常麻木之间的相互作用，可以为一般哺乳动物，特别是人类的这些过程的调控提供重要的见解。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，与低温相一致的新陈代谢、血流等的减少可能是非常有益的。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。这项拟议的研究解决了调控生物学中的基本问题，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.