bang-bang control of feeding role of hypothalamic and satiety signals砰砰的枪声喂养下丘脑和饱腹感的作用信号的控制.pdf

Bang-Bang Control of Feeding: Role of Hypothalamic and Satiety Signals B. Silvano Zanutto1,2*, John E. R. Staddon3 ´ ´ ´ 1 Instituto de Ingenierıa Biomedica–Universidad de Buenos Aires, Buenos Aires, Argentina, 2 Instituto de Biologıa y Medicina Experimental–Consejo Nacional de ´ ´ Investigaciones Cientıficas y Tecnicas, Buenos Aires, Argentina, 3 Department of Psychology and Neuroscience, Duke University, Durham, North Carolina, United States of America Rats, people, and many other omnivores eat in meals rather than continuously. We show by experimental test that eating in meals is regulated by a simple bang-bang control system, an idea foreshadowed by Le Magnen and many others, shown by us to account for a wide range of behavioral data, but never explicitly tested or tied to neurophysiological facts. The hypothesis is simply that the tendency to eat rises with time at a rate determined by satiety signals. When these signals fall below a set point, eating begins, in on–off fashion. The delayed sequelae of eating increment the satiety signals, which eventually turn eating off. Thus, under free conditions, the organism eats in bouts separated by noneating activities. We report an experiment with rats to test novel predictions about meal patterns that are not explained by existing homeostatic approaches. Access to food was systematically but unpredictably interrupted just as the animal tried to start a new meal. A simple bang-bang model fits the resulting meal-pattern data well, and its elements can be identified with neurophysiological processes. Hypothalamic inputs can provide the set point for longer-term regulation carried out by a comparator in the hindbrain. Delayed gustatory and gastrointes