University of California, Berkeley, Berkeley, United States.
Janelia Research Campus, Howard Hughes Medical Institute, Chevy Chase, United States.
Elife. 2022 Jul 6;11:e79887. doi: 10.7554/eLife.79887.
Taste detection and hunger state dynamically regulate the decision to initiate feeding. To study how context-appropriate feeding decisions are generated, we combined synaptic resolution circuit reconstruction with targeted genetic access to specific neurons to elucidate a gustatory sensorimotor circuit for feeding initiation in adult . This circuit connects gustatory sensory neurons to proboscis motor neurons through three intermediate layers. Most neurons in this pathway are necessary and sufficient for proboscis extension, a feeding initiation behavior, and respond selectively to sugar taste detection. Pathway activity is amplified by hunger signals that act at select second-order neurons to promote feeding initiation in food-deprived animals. In contrast, the feeding initiation circuit is inhibited by a bitter taste pathway that impinges on premotor neurons, illuminating a local motif that weighs sugar and bitter taste detection to adjust the behavioral outcomes. Together, these studies reveal central mechanisms for the integration of external taste detection and internal nutritive state to flexibly execute a critical feeding decision.
味觉检测和饥饿状态会动态调节开始进食的决策。为了研究如何生成适当的进食决策，我们将突触分辨率电路重建与针对特定神经元的靶向遗传方法相结合，以阐明成年 中启动进食的味觉感觉运动回路。该回路通过三个中间层将味觉感觉神经元连接到喙运动神经元。该通路中的大多数神经元对于喙延伸（一种进食起始行为）是必需且充分的，并且对糖味检测有选择性反应。饥饿信号会放大通路活性，这些信号作用于特定的二阶神经元，以促进食物剥夺动物的进食起始。相比之下，进食起始回路被苦味通路抑制，苦味通路作用于前运动神经元，揭示了一个局部模式，该模式权衡糖和苦味检测以调整行为结果。总之，这些研究揭示了整合外部味觉检测和内部营养状态以灵活执行关键进食决策的中枢机制。
