The John B. Pierce Laboratory, New Haven, Connecticut.
Department of Cellular and Molecular Physiology, Yale Medical School, New Haven, Connecticut.
Acta Physiol (Oxf). 2019 Jan;225(1):e13152. doi: 10.1111/apha.13152. Epub 2018 Jun 27.
Predicting the uncertainties of the ever-changing environment provides a competitive advantage for animals. The need to anticipate food sources has provided a strong evolutionary drive for synchronizing behavioural and internal processes with daily circadian cycles. When food is restricted to a few hours per day, rodents exhibit increased wakefulness and foraging behaviour preceding the arrival of food. Interestingly, while the master clock located in the suprachiasmatic nucleus entrains daily rhythms to the light cycle, it is not necessary for this food anticipatory activity. This suggests the existence of a food-entrained oscillator located elsewhere. Based on the role of nigrostriatal dopamine in reward processing, motor function, working memory and internal timekeeping, we propose a working model by which food-entrained dopamine oscillations in the dorsal striatum can enable animals maintained on a restricted feeding schedule to anticipate food arrival. Finally, we summarize how metabolic signals in the gut are conveyed to the nigrostriatal pathway to suggest possible insight into potential input mechanisms for food anticipatory activity.
预测不断变化的环境中的不确定性为动物提供了竞争优势。动物需要预测食物来源，这为将行为和内部过程与日常昼夜节律同步提供了强大的进化动力。当食物每天只限于几个小时时，啮齿动物在食物到达之前会表现出更多的觉醒和觅食行为。有趣的是，虽然位于视交叉上核的主时钟将日常节律与光周期同步，但这对于这种食物预期活动并非必需。这表明存在位于其他地方的食物同步振荡器。基于黑质纹状体多巴胺在奖励处理、运动功能、工作记忆和内部计时中的作用，我们提出了一个工作模型，即背侧纹状体中的食物同步多巴胺振荡可以使按限制进食时间表饲养的动物预测食物的到来。最后，我们总结了肠道中的代谢信号如何传递到黑质纹状体通路，以提出对食物预期活动潜在输入机制的可能见解。
