美国洛克菲勒大学Jeffrey M. Friedman、Sarah A. Stern等研究人员合作发现，岛叶皮层Nos1神经元调控食物过度消耗。相关论文于2021年3月23日在线发表在《细胞—代谢》杂志上。

研究人员表示，联想学习使得动物根据环境信息适应其行为。例如，与食物供应量相关的感官提示甚至会导致动物过度消耗食物。但是，这背后的神经机制了解甚少。

为了研究这一点，研究人员最近开发了一个行为任务，其中环境提示甚至可以使处于饱足状态的小鼠也能增加进食。研究人员发现，岛叶皮层到中央杏仁核回路对于条件性过度消耗是必要的，但对于稳态进食则不是必需的。这种投射是由表达谷氨酸能一氧化氮合酶-1（Nos1）的神经元数量所标记，这些神经元在进食过程中特别活跃。

最后，研究人员证明了岛叶皮层Nos1神经元的激活抑制了中央杏仁核中的饱腹感信号。因此，这些数据表明，岛叶皮层提供了对稳态回路的自上而下控制，从而响应于获得的提示来促进过度消耗。 

附：英文原文

Title: Top-down control of conditioned overconsumption is mediated by insular cortex Nos1 neurons

Author: Sarah A. Stern, Estefania P. Azevedo, Lisa E. Pomeranz, Katherine R. Doerig, Violet J. Ivan, Jeffrey M. Friedman

Issue&Volume: 2021-03-23

Abstract: Associative learning allows animals to adapt their behavior in response to environmentalcues. For example, sensory cues associated with food availability can trigger overconsumptioneven in sated animals. However, the neural mechanisms mediating cue-driven non-homeostaticfeeding are poorly understood. To study this, we recently developed a behavioral taskin which contextual cues increase feeding even in sated mice. Here, we show that aninsular cortex to central amygdala circuit is necessary for conditioned overconsumption,but not for homeostatic feeding. This projection is marked by a population of glutamatergicnitric oxide synthase-1 (Nos1)-expressing neurons, which are specifically active duringfeeding bouts. Finally, we show that activation of insular cortex Nos1 neurons suppressessatiety signals in the central amygdala. The data, thus, indicate that the insularcortex provides top-down control of homeostatic circuits to promote overconsumptionin response to learned cues.

DOI: 10.1016/j.cmet.2021.03.001

Source: https://www.cell.com/cell-metabolism/fulltext/S1550-4131(21)00108-X