Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada.
Département de Neurosciences, Université de Montréal, Québec, Canada.
Elife. 2017 Oct 20;6:e28143. doi: 10.7554/eLife.28143.
We test the hypothesis that the posterior parietal cortex (PPC) contributes to the control of visually guided locomotor gait modifications by constructing an estimation of object location relative to body state, and in particular the changing gap between them. To test this hypothesis, we recorded neuronal activity from areas 5b and 7 of the PPC of cats walking on a treadmill and stepping over a moving obstacle whose speed of advance was varied (slowed or accelerated with respect to the speed of the cat). We found distinct populations of neurons in the PPC, primarily in area 5b, that signaled distance- or time-to-contact with the obstacle, regardless of which limb was the first to step over the obstacle. We propose that these cells are involved in a sensorimotor transformation whereby information on the location of an obstacle with respect to the body is used to initiate the gait modification.
我们通过构建相对于身体状态（尤其是它们之间不断变化的间隙）的物体位置的估计值来检验后顶叶皮层 (PPC) 有助于控制视觉引导的运动步态改变的假说。为了检验这一假设，我们记录了在跑步机上行走的猫的 PPC 区 5b 和 7 中的神经元活动，同时猫要跨过一个移动的障碍物，其前进速度会变化（相对于猫的速度减慢或加速）。我们在 PPC 中发现了不同的神经元群体，主要在 5b 区，它们与障碍物的距离或时间接触信号无关，无论哪条腿先跨过障碍物。我们提出，这些细胞参与了一种运动感觉转换，借此信息用于启动步态改变。
