Umezaki Yujiro, Hidalgo Sergio, Nguyen Erika, Nguyen Tiffany, Suh Jay, Uchino Sheena S, Chiu Joanna, Hamada Fumika
Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States.
Department of Entomology and Nematology, University of California, Davis, Davis, United States.
Elife. 2024 Dec 2;13:RP94703. doi: 10.7554/eLife.94703.
Hungry animals consistently show a desire to obtain food. Even a brief sensory detection of food can trigger bursts of physiological and behavioral changes. However, the underlying mechanisms by which the sensation of food triggers the acute behavioral response remain elusive. We have previously shown in that hunger drives a preference for low temperature. Because is a small ectotherm, a preference for low temperature implies a low body temperature and a low metabolic rate. Here, we show that taste-sensing triggers a switch from a low to a high temperature preference in hungry flies. We show that taste stimulation by artificial sweeteners or optogenetics triggers an acute warm preference, but is not sufficient to reach the fed state. Instead, nutrient intake is required to reach the fed state. The data suggest that starvation recovery is controlled by two components: taste-evoked and nutrient-induced warm preferences, and that taste and nutrient quality play distinct roles in starvation recovery. Animals are motivated to eat based on time of day or hunger. We found that clock genes and hunger signals profoundly control the taste-evoked warm preferences. Thus, our data suggest that the taste-evoked response is one of the critical layers of regulatory mechanisms representing internal energy homeostasis and metabolism.
饥饿的动物始终表现出获取食物的欲望。即使是对食物的短暂感官察觉也能引发一系列生理和行为变化。然而，食物感觉触发急性行为反应的潜在机制仍然难以捉摸。我们之前已经表明，饥饿会导致对低温的偏好。由于[此处可能缺失某种动物名称]是一种小型变温动物，对低温的偏好意味着体温较低且代谢率较低。在这里，我们表明味觉感知会触发饥饿果蝇从低温偏好转向高温偏好。我们发现，人工甜味剂或光遗传学引起的味觉刺激会引发急性的温暖偏好，但不足以达到饱腹状态。相反，达到饱腹状态需要摄入营养物质。数据表明，饥饿恢复由两个因素控制：味觉诱发的和营养诱导的温暖偏好，并且味觉和营养质量在饥饿恢复中发挥着不同的作用。动物会根据一天中的时间或饥饿程度产生进食的动机。我们发现，生物钟基因和饥饿信号深刻地控制着味觉诱发的温暖偏好。因此，我们的数据表明，味觉诱发反应是代表内部能量稳态和新陈代谢的调控机制的关键层面之一。
