Spatiotemporal Structure of Sensory Acquisition Behaviors: Experiments on the Rat Vibrissal System

当你用手探索一个物体时，或者你根据你行走的表面类型改变你的脚步，你的触觉与你的动作无缝结合。 你的大脑是如何完成这一壮举的？ 这是一个很大的开放性问题，很难单独使用人类研究来回答。 本计画将借由大鼠触须系统的研究来探讨这个问题。 老鼠来回移动它们的胡须来触摸和探索不同的物体，就像人类用手一样。 触觉信息从胡须的底部通过大脑中的一系列处理阶段传递。 该研究项目的重点是了解在第二阶段发生的处理，在称为“三叉神经脊束核”（SpVi）的大脑结构中。 在项目的第一部分，计算机模拟和机器人模型将用于测试SpVi中可能发生的不同类型处理的可兼容性。 在该项目的第二部分，将开发测量老鼠胡须与不同物体精确接触时间和位置的技术。 最后，在项目的第三部分，来自SpVi神经元的电信号将被记录下来，并与动物接触不同物体时的持续行为相关联。 出现的结果将允许测试三个不同的假设发生在SpVi的处理。 无论哪种假设是正确的，研究结果都将提高对大脑如何结合感知和运动来让动物感知世界的理解。 该项目将有助于对两名研究生进行跨学科培训，并有助于西北大学正在进行的研究生课程开发。 它还将为至少六名本科生提供有意义的工程研究机会，并特别努力将妇女和代表性不足的少数民族包括在内。

When you explore an object using your hands, or you change your footsteps based on the type of surface you are walking on, your sense of touch is seamlessly combined with the movements you make. How does your brain accomplish this feat? This is a large, open question that is difficult to answer using human studies alone. This project will investigate this question by studying the rat whisker (vibrissal) system. Rats move their whiskers back and forth to touch and explore different objects, much as humans use their hands. The tactile information is conveyed from the base of the whiskers through a series of processing stages in the brain. This research project focuses on understanding the processing that occurs in the second stage, in a brain structure called "spinal trigeminal nucleus interpolaris" (SpVi). In the first part of the project, computer simulations and robotic models will be used to test the plausibility of the different types of processing that might occur in SpVi. In the second part of the project, technology to measure the precise contact times and locations of a rat's whiskers with different objects will be developed. Finally, in the third part of the project, electrical signals from neurons in SpVi, will be recorded and correlated with the animal's ongoing behavior as it touches different objects. The results that emerge will allow the testing of three different hypotheses for the processing that occurs in SpVi. Regardless of which hypothesis(es) is/are found to be correct, the results will improve the understanding of how the brain combines sensing and movement to allow animals to perceive the world. This project will contribute to the interdisciplinary training of two graduate students and to ongoing graduate-level course development at Northwestern University. It will also provide meaningful research opportunities in engineering for at least six undergraduates, with a specific effort made to include women and underrepresented minorities.