Entrainment by a palatable meal induces food-anticipatory activity and c-Fos expression in reward-related areas of the brain
Entrainment by a palatable meal induces food-anticipatory activity and c-Fos expression in reward-related areas of the brain
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DOI：
10.1016/j.neuroscience.2005.01.064
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发表时间：
2005-01-01
期刊：
影响因子：
3.3
通讯作者：
Escobar, C
中科院分区：
文献类型：
--
作者：
Mendoza, J;Angeles-Castellanos, M;Escobar, C
在限制喂养计划（RFS）下维持的大鼠会产生食物预期活动和生理参数的夹带。食物夹带独立于视交叉上核，并且取决于食物夹带振荡器（FEO）。限制喂养计划会导致动物进入分解代谢状态并增加其食物驱动的动力，这表明在此过程中涉及代谢和奖励相关机制。这项研究探讨了美味膳食所驱动的动机是否足以产生食物夹带。为了解决这个问题，我们评估了在不剥夺食物的情况下，每天固定摄入高适口膳食（PME）是否能维持大鼠的运动活动、血清葡萄糖和游离脂肪酸浓度。将 PME 大鼠的夹带反应与 RFS 夹带的大鼠进行比较。在第二个实验中，我们使用 c-Fos-IR 来识别与 PME 相关的中枢神经系统结构。大鼠对每日可口膳食表现出预期活动，其强度低于接受 RFS 的大鼠。在中断美味膳食后，预期活动至少持续四个周期，表明这种持续性取决于内源性振荡器。 PME 大鼠中没有夹带葡萄糖和游离脂肪酸。边缘系统核中的 c-Fos 表达与 PME 时间同相，但下丘脑中则不同。结果表明：1）食物匮乏，即分解代谢状态对于预期活动的表达不是必需的； 2) 由于可口膳食的味道和/或营养成分而引起的动机状态的增加足以诱导行为； 3）边缘系统的结构参与了这一夹带过程。本研究表明代谢和动机机制参与食物夹带，并表明 FEO 可能是分布在大脑中不同调节系统的多振荡系统。 (c) 2005 年由 Elsevier Ltd 代表 IBRO 出版。
Rats maintained under restricted feeding schedules (RFS) develop food-anticipatory activity and entrainment of physiological parameters. Food entrainment is independent of the suprachiasmatic nucleus and depends on food-entrainable oscillators (FEO). Restricted feeding schedules lead animals toward a catabolic state and to increase their food driven motivation, suggesting that in this process metabolic- and reward-related mechanisms are implicated. This study explored if motivation driven by a palatable meal is sufficient to produce food-entrainment. To address this question, we evaluated whether daily fixed access to a highly palatable meal entrained (PME) locomotor activity, serum glucose and free fatty acids concentrations in rats maintained without food deprivation. The entrained response of PME rats was compared with rats entrained to RFS. In a second experiment, we used c-Fos-IR to identify structures in the central nervous system involved with PME. Rats showed anticipatory activity to a daily palatable meal, with a lower intensity than rats entrained to RFS. Anticipatory activity persisted at least for four cycles after interrupting palatable meal, suggesting that this persistence depends on an endogenous oscillator. Glucose and free fatty acids were not entrained in PME rats. c-Fos expression in limbic system nuclei was in phase with PME time, but not in the hypothalamus. Results suggest 1) that food deprivation, i.e. a catabolic state is not necessary for the expression of anticipatory activity; 2) that an increase in the motivational state due to taste and/or nutritional contents of palatable meal is sufficient to entrain behavior; and 3) that structures in the limbic system are involved in this entrainment process. The present study indicates that metabolic and motivational mechanisms are involved in food entrainment, and suggests that the FEO may be a multi-oscillatory system distributed over different regulatory systems in the brain. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.