Lafferty Danielle S, Isaac Jeremiah, Wolcott Joelyz S, Phan Amy, Lutas Andrew
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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bioRxiv. 2025 Jun 8:2025.06.05.657686. doi: 10.1101/2025.06.05.657686.
Despite internal cues that signal fullness, animals can continue eating when motivated by context or palatability. The neural pathways and signals that enable animals to override these fullness cues remain unclear. We examined a central amygdala (CeA) projection to the dorsolateral pons that targets the parabrachial nucleus, a well-established meal termination center, and the adjacent supratrigeminal nucleus, a region that controls orofacial movements. Activity in this CeA pathway correlated with the animal's licking behavior but was not modulated by metabolic need or palatability cues. CeA stimulation caused animals to overeat, consume non-edible objects within reach, or exhibit ingestion-like behaviors-licking, chewing, and grasping-even when no target was present. Depending on training and context, stimulation elicited either licking or pellet consumption, suggesting that CeA promotes a flexible, goal-directed ingestive state by recruiting consummatory motor circuits rather than simply suppressing satiety signals. These findings highlight how forebrain-brainstem interactions can re-engage feeding behavior beyond homeostatic need.
尽管存在表明饱腹感的内部信号，但当受到环境或适口性的驱动时，动物仍会继续进食。使动物能够忽略这些饱腹感信号的神经通路和信号仍不清楚。我们研究了中央杏仁核（CeA）向脑桥背外侧的投射，该投射靶向臂旁核（一个成熟的进食终止中心）和相邻的三叉上核（一个控制口面部运动的区域）。这条CeA通路中的活动与动物的舔舐行为相关，但不受代谢需求或适口性信号的调节。CeA刺激会导致动物过度进食、食用够得着的非食用物体，或者表现出类似摄食的行为——舔舐、咀嚼和抓取——即使没有目标物也会如此。根据训练和环境的不同，刺激会引发舔舐或食用颗粒，这表明CeA通过招募完成性运动回路来促进一种灵活的、目标导向的摄食状态，而不是简单地抑制饱腹感信号。这些发现凸显了前脑与脑干之间的相互作用如何能够在超出稳态需求的情况下重新引发进食行为。
