Activity-induced reward and related phenomena

我对运动的激励/奖励效应的兴趣源于对大鼠活动性厌食症的研究，这是一种人类神经性厌食症的动物模型。为了产生活动性厌食症，允许大鼠每天有限地接触食物（例如60分钟）。一天中剩下的时间，这些老鼠可以使用滚轮。老鼠在轮子里跑，体重减轻；他们减得越多，跑得越多。有些老鼠一天能跑20公里。此外，他们在日常饮食中没有摄入足够的能量来补偿在跑步中消耗的能量，所以，如果这个过程继续下去，死亡就会随之而来。更神奇的是，跑步可以抑制饮食。这些老鼠在日常饮食中比其他同样被剥夺食物但不被允许跑步的老鼠吃得少。B. T. Lett博士和我开始了一个研究项目，基于这样一个假设：过度的轮转及其对饮食的影响涉及到大脑中奖赏系统的激活——也许与吗啡或安非他明等成瘾药物激活的系统是一样的。这项研究计划的主要目的是为了更好地理解运动的激励作用和奖励作用。反过来，这应该有助于更好地理解奖励和动机的行为和神经机制。本研究至少有两项应用具有普遍意义：1。大鼠活动性厌食症被认为是人类神经性厌食症的动物模型，因此关于大鼠活动性厌食症的原因和机制的任何信息都可能对理解和治疗人类神经性厌食症具有实际意义。2. 一些非药物的有益活动，比如运动，会让人上瘾，这种观点正被越来越多的人接受。因此，我们对老鼠的滚轮跑步运动的研究可能会对运动成瘾产生影响，更普遍地说，对其他非药物奖励活动（赌博、饮食等）的成瘾也会产生影响。

My interest in the motivational/rewarding effects of exercise stems from studies of activity anorexia in rats, an animal model of anorexia nervosa in humans. To produce activity anorexia, rats are allowed limited daily access to food (e.g., 60 min). The rest of the day these rats have access to running wheels. The rats run in the wheels and lose weight; the more weight they lose, the more they run. Some rats run as much as 20 km a day. Moreover, they do not eat enough during their daily meal to compensate for the energy expended in running, so, if the process is allowed to continue, death ensues. Even more amazing is the fact that running suppresses eating. These rats eat less during their daily meal than other rats that are similarly food deprived, but not allowed to run.      Dr. B. T. Lett and I started a research program based on the hypothesis that the excessive wheel running and its effects on eating involve activation of a reward system in the brain - perhaps the same system as that activated by addictive drugs such as morphine or amphetamine. The main objective of the proposed research program is to arrive at a better understanding of the motivational and rewarding effects of exercise. In turn, this should contribute to a greater understanding of the behavioral and neural mechanisms of reward and motivation.      At least two applications of the work are of general significance: 1. Activity anorexia in rats is considered an animal model of anorexia nervosa in humans, so any information about the causes and mechanisms of the phenomenon in rats may have practical implications for understanding and treating the disorder in humans. 2. The view that certain nondrug rewarding activities, like exercise, are addictive is becoming more accepted. Thus our research on wheel-running exercise in rats may have implications for exercise addiction, and, more generally, for addictions to other nondrug rewarding activities (gambling, eating, etc.)