Energy Balance and Control of Physiological Dormancy

能量平衡和体温的恒定是由大脑控制的，这与动物身体和环境的变化有关。在这里，我们将尝试通过研究一种特殊情况来研究这种调节系统的特点：一种已知最小的温血动物蜂鸟在夜间短暂的1-10小时内放弃了正常的体温恒定，作为一种节约能量的措施。与冬眠的哺乳动物一样，蜂鸟也会进入一种冬眠的生理状态，新陈代谢率和体温都大大降低。关于鸟的内部状态和环境的信息的种类将被确定，这些信息是由引发麻木的生理控制系统整合的。冬眠在实现长距离迁徙所需的快速和反复的体重增加中所起的特殊作用也将被研究。虽然蜂鸟进入了鸟类中已知的最深的冬眠状态，但几乎每一种被研究的鸟类，以及许多哺乳动物，在能量短缺的时候都会在一定程度上降低夜间的体温和代谢率。昏睡似乎也类似于人类的睡眠。因此，蜂鸟的冬眠为研究一系列普遍重要的生理基础提供了一个机会，它具有恒定调节规则的例外所提供的特殊实验优势。

Energy balance and constancy of body temperature are controlled by the brain in relation to changing conditions of an animal's body and environment. An attempt will be made here to investigate the characteristics of this regulatory system by studying an exceptional situation: the brief nightly period of 1-10 hours when the normal constancy of body temperature is abandoned as an energy conserving measure by one of the smallest known warm- blooded animals, a hummingbird. Like hibernating mammals, hummingbirds can enter a physiological state of torpor, in which metabolic rate and body temperature are greatly reduced. The kind of information about the internal state of the bird and the environment that is integrated by the physiological control system that initiates torpor will be determined. The special role of torpor in making possible the rapid and repeated weight gain necessary to achieve long-distance migration will also be investigated. Although hummingbirds enter the deepest state of torpor known among birds, almost every species of bird studied, as well as many mammals, reduce nighttime body temperature and metabolic rate to some degree in times of energy shortage. Torpor also appears to be analagous to human sleep. Thus torpor in hummingbirds provides an opportunity to study series of generally important physiological fundamentals with the special experimental advantages afforded by an exception to the rule of constant regulation.