The Solomon H. Snyder Department of Neuroscience, Krieger Mind/Brain Institute, Kavli Neuroscience Discovery Institute, Brain Science Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Undergraduate Studies, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD, USA.
Nature. 2022 Mar;603(7901):464-469. doi: 10.1038/s41586-022-04478-7. Epub 2022 Mar 9.
The brain generates complex sequences of movements that can be flexibly configured based on behavioural context or real-time sensory feedback, but how this occurs is not fully understood. Here we developed a 'sequence licking' task in which mice directed their tongue to a target that moved through a series of locations. Mice could rapidly branch the sequence online based on tactile feedback. Closed-loop optogenetics and electrophysiology revealed that the tongue and jaw regions of the primary somatosensory (S1TJ) and motor (M1TJ) cortices encoded and controlled tongue kinematics at the level of individual licks. By contrast, the tongue 'premotor' (anterolateral motor) cortex encoded latent variables including intended lick angle, sequence identity and progress towards the reward that marked successful sequence execution. Movement-nonspecific sequence branching signals occurred in the anterolateral motor cortex and M1TJ. Our results reveal a set of key cortical areas for flexible and context-informed sequence generation.
大脑生成复杂的运动序列，这些序列可以根据行为背景或实时感官反馈灵活配置，但具体是如何实现的还不完全清楚。在这里，我们开发了一种“序列舔食”任务，在这个任务中，老鼠将舌头伸向一个通过一系列位置移动的目标。老鼠可以根据触觉反馈在线快速分支序列。闭环光遗传学和电生理学显示，初级体感（S1TJ）和运动（M1TJ）皮质的舌和颌区域在单个舔食的水平上对舌运动学进行编码和控制。相比之下，舌“运动前区”（前外侧运动区）编码了潜在变量，包括预期的舔食角度、序列身份和朝着奖励的进展，这些变量标志着成功执行了序列。运动特异性的序列分支信号出现在前外侧运动区和 M1TJ 中。我们的结果揭示了一组关键的皮质区域，用于灵活和情境感知的序列生成。
