Persons J E, Stephan F K, Bays M E
Department of Psychology, Florida State University, Tallahassee 32306-1051.
Physiol Behav. 1993 Jul;54(1):55-64. doi: 10.1016/0031-9384(93)90043-f.
Rats were housed in hanging cages and given ad lib access to food (control), approximately 20 g food/day (lean), or a palatable high-fat diet (fat). After body weights diverged, rats were transferred to activity wheels. When food access was reduced to 2 h/day, all control and lean rats displayed anticipatory activity (AA), while only two of eight fat rats anticipated the meals. Baseline activity levels and nonanticipatory wheel running were only marginally reduced in fat rats. In a second experiment, conducted entirely in activity wheels, rats were maintained on curtailed food or a high-fat diet until body weights diverged. Food access was then reduced to 2 h/day and the diets were reversed. Lean rats given restricted access to the high-fat diet gained weight and four of eight rats showed AA. Fat rats switched to chow lost weight and all eight rats displayed AA. The results indicate that body weight changes induced by diet manipulations result in a striking and rather selective reduction in the anticipation of daily meals. This effect is ascribed to a modulation of the output of a circadian pacemaker that entrains running-wheel activity to daily meals.
将大鼠饲养在悬挂式笼子中，给予它们随意获取食物的机会（对照组）、每天约20克食物（瘦型组）或美味的高脂饮食（肥胖组）。当体重出现差异后，将大鼠转移到活动轮上。当食物获取时间减少到每天2小时时，所有对照组和瘦型组大鼠都表现出预期活动（AA），而八只肥胖组大鼠中只有两只对进食有预期。肥胖组大鼠的基线活动水平和非预期的转轮运动仅略有降低。在完全在活动轮上进行的第二项实验中，大鼠维持受限食物或高脂饮食，直到体重出现差异。然后将食物获取时间减少到每天2小时，并颠倒饮食。给予高脂饮食但进食受限的瘦型组大鼠体重增加，八只大鼠中有四只表现出AA。改为食用普通食物的肥胖组大鼠体重减轻，所有八只大鼠都表现出AA。结果表明，饮食操纵引起的体重变化导致每日进食预期的显著且相当有选择性的降低。这种效应归因于昼夜节律起搏器输出的调节，该起搏器使转轮活动与每日进食同步。
