Livneh Yoav, Ramesh Rohan N, Burgess Christian R, Levandowski Kirsten M, Madara Joseph C, Fenselau Henning, Goldey Glenn J, Diaz Veronica E, Jikomes Nick, Resch Jon M, Lowell Bradford B, Andermann Mark L
Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature. 2017 Jun 29;546(7660):611-616. doi: 10.1038/nature22375. Epub 2017 Jun 14.
Physiological needs bias perception and attention to relevant sensory cues. This process is 'hijacked' by drug addiction, causing cue-induced cravings and relapse. Similarly, its dysregulation contributes to failed diets, obesity, and eating disorders. Neuroimaging studies in humans have implicated insular cortex in these phenomena. However, it remains unclear how 'cognitive' cortical representations of motivationally relevant cues are biased by subcortical circuits that drive specific motivational states. Here we develop a microprism-based cellular imaging approach to monitor visual cue responses in the insular cortex of behaving mice across hunger states. Insular cortex neurons demonstrate food-cue-biased responses that are abolished during satiety. Unexpectedly, while multiple satiety-related visceral signals converge in insular cortex, chemogenetic activation of hypothalamic 'hunger neurons' (expressing agouti-related peptide (AgRP)) bypasses these signals to restore hunger-like response patterns in insular cortex. Circuit mapping and pathway-specific manipulations uncover a pathway from AgRP neurons to insular cortex via the paraventricular thalamus and basolateral amygdala. These results reveal a neural basis for state-specific biased processing of motivationally relevant cues.
生理需求会使对相关感觉线索的感知和注意力产生偏差。这一过程被药物成瘾“劫持”,导致线索诱发的渴望和复吸。同样,其失调会导致节食失败、肥胖和饮食失调。对人类的神经影像学研究表明,岛叶皮质与这些现象有关。然而,目前尚不清楚驱动特定动机状态的皮层下回路如何使与动机相关线索的“认知”皮层表征产生偏差。在这里,我们开发了一种基于微棱镜的细胞成像方法,以监测行为小鼠在不同饥饿状态下岛叶皮质对视觉线索的反应。岛叶皮质神经元表现出对食物线索的偏向性反应,而在饱腹感时这种反应会消失。出乎意料的是,虽然多个与饱腹感相关的内脏信号在岛叶皮质汇聚,但下丘脑“饥饿神经元”(表达刺鼠相关肽(AgRP))的化学遗传激活绕过了这些信号,从而在岛叶皮质恢复了类似饥饿的反应模式。回路映射和通路特异性操作揭示了一条从AgRP神经元经室旁丘脑和基底外侧杏仁核到岛叶皮质的通路。这些结果揭示了动机相关线索的状态特异性偏向性处理的神经基础。