美国康奈尔大学Jesse H. Goldberg和Brendan S. Ito共同合作，近期取得重要工作进展。他们研究提出，触觉引导舌头控制的上丘机械感知运动地图。相关研究成果2025年1月1日在线发表于《自然》杂志上。

据介绍，准确的目标导向行为需要触觉与身体位置和持续运动的信息相结合。咀嚼、吞咽和说话等行为严重依赖于快速移动的舌头上的精确触觉事件，但动态触觉引导舌头控制的神经回路尚不清楚。

研究人员使用高速录像技术，研究了小鼠在舔舐过程中从意外改变位置的喷水口喝水时的三维舌运动学，需要重新瞄准以应对舌头左、中或右表面的微妙接触事件。小鼠整合了关于精确触摸事件和舌头位置的信息，以重新定位随后的舔舐。研究人员发现，触觉引导的重新瞄准不受舌感觉、前运动和运动皮层光失活的影响，但受到外侧上丘光失活（latSC）的损害。

电生理记录确定了latSC神经元具有机械感觉感受野，用于精确的触觉事件，这些事件锚定在以舌头为中心、以头部为中心或连接参考框架的精确触摸事件。latSC神经元在接触前也编码了舌头的位置，这些信息对于基于舌头到头部的坐标变换非常重要，这些坐标变换是精确触摸引导瞄准的基础。病毒追踪揭示了舌三叉神经核对latSC的舌感觉输入，latSC中的光学微刺激揭示了瞄准舔舐的地形图。

总之，这一研究表明，触觉引导的舌头控制依赖于一个上丘机械感知-运动地图，这类似于跨多种物种中与视觉引导定向相关的上丘视觉-运动地图。

附：英文原文

Title: A collicular map for touch-guided tongue control

Author: Ito, Brendan S., Gao, Yongjie, Kardon, Brian, Goldberg, Jesse H.

Issue&Volume: 2025-01-01

Abstract: Accurate goal-directed behaviour requires the sense of touch to be integrated with information about body position and ongoing motion1,2. Behaviours such as chewing, swallowing and speech critically depend on precise tactile events on a rapidly moving tongue3, but neural circuits for dynamic touch-guided tongue control are unknown. Here, using high-speed videography, we examined three-dimensional lingual kinematics as mice drank from a water spout that unexpectedly changed position during licking, requiring re-aiming in response to subtle contact events on the left, centre or right surface of the tongue. Mice integrated information about both precise touch events and tongue position to re-aim ensuing licks. Touch-guided re-aiming was unaffected by photoinactivation of tongue sensory, premotor and motor cortices, but was impaired by photoinactivation of the lateral superior colliculus (latSC). Electrophysiological recordings identified latSC neurons with mechanosensory receptive fields for precise touch events that were anchored in tongue-centred, head-centred or conjunctive reference frames. Notably, latSC neurons also encoded tongue position before contact, information that is important for tongue-to-head-based coordinate transformations underlying accurate touch-guided aiming. Viral tracing revealed tongue sensory inputs to the latSC from the lingual trigeminal nucleus, and optical microstimulation in the latSC revealed a topographic map for aiming licks. These findings demonstrate that touch-guided tongue control relies on a collicular mechanosensorimotor map, analogous to collicular visuomotor maps associated with visually guided orienting across many species.

DOI: 10.1038/s41586-024-08339-3

Source: https://www.nature.com/articles/s41586-024-08339-3