Effect of motor control on sensory coding in the awake, behaving mouse

我们对感觉的神经机制的认识主要来自被动实验范式，其中感觉刺激被呈现给麻醉动物的固定感觉器官（例如，投射在视网膜上的光点）。然而，大多数物种通过协调感觉器官的运动控制来主动寻求信息（例如，眼睛，手，胡须）与感官处理（'主动感知'）。事实上，感觉感受器的活动会受到感觉器官运动的强烈影响：如果眼球运动消失，视觉图像就会消失。由于技术限制，运动控制可能对感觉编码产生重要影响的担忧在过去很难完全解决。类似于人类使用运动控制通过手和眼睛的运动来探索物体的方式，啮齿动物通过有节奏地前后扫动胡须（“拂动”）来探索它们的环境。胡须感觉对这些动物来说极其重要：它支配着大脑的躯体感觉区域。大鼠/小鼠的胡须感觉提供了一个很好的模型系统，可以深入了解这个提议的中心问题-感觉机制如何依赖于运动控制。现在可以使用高速摄像机精确测量胡须如何移动和与物体相互作用。此外，由于工程师们一直对杆状物体如何弯曲感兴趣，因此有一个成熟的数学理论可以用来从视频数据中估计胡须-物体相互作用的机械力，我们感知世界的方式从根本上受到初级感觉神经元的限制，初级感觉神经元将环境中的信号（例如胡须的弯曲）转化为相应的动作电位模式。在这里，我们建议确定触觉功能，主要的胡须神经元编码的鼠标积极探索其胡须的对象。这项工作的重要性在于，它将提供对运动控制（这里是搅拌）和感觉处理如何相互作用以限制我们感知世界的一般问题的洞察。

Our knowledge of the neural mechanisms of sensation comes mainly from a passive experimental paradigm where sensory stimuli are presented to the immobilised sense organ of an anaesthetised animal (e.g., spot of light projected on the retina). However, most species actively seek information by coordinating motor control of their sense organs (e.g., eyes, hands, whiskers) with sensory processing ('active sensing'). Indeed, the activity of sensory receptors can be strongly affected by sense organ movements: if eye movement is abolished, the visual image fades away. The concern that motor control might have an important impact on sensory coding was difficult to address fully in the past due to technical limitations.Analogously to the way that humans use motor control to explore objects by movement of our hands and eyes, rodents explore their environment by rhythmically sweeping their whiskers backwards and forwards ('whisking'). The whisker sense is extremely important to these animals: it dominates the brain's somatosensory areas. The whisker sense of rats/mice offers an excellent model system to get insight into the central question of this proposal - how sensory mechanisms depend on motor control. How the whiskers move and interact with objects can now be precisely measured using high-speed video cameras. Moreover, since engineers have long been interested in how rod-like objects bend, there is a well-developed mathematical theory that can be used to estimate the mechanical forces of whisker-object interaction from video data.The way that we perceive the world is fundamentally constrained by primary sensory neurons, which translate signals in the environment (such as bending of a whisker) into corresponding patterns of action potentials. Here, we propose to determine the tactile features that primary whisker neurons encode as a mouse actively explores objects with its whiskers. The significance of the work is that it will provide insight into the general question of how motor control (here, whisking) and sensory processing interact to constrain how we perceive the world.