Harding-Forrester Samuel, Feldman Daniel E
Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States.
Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States.
Handb Clin Neurol. 2018;151:73-102. doi: 10.1016/B978-0-444-63622-5.00004-8.
Somatosensory areas containing topographic maps of the body surface are a major feature of parietal cortex. In primates, parietal cortex contains four somatosensory areas, each with its own map, with the primary cutaneous map in area 3b. Rodents have at least three parietal somatosensory areas. Maps are not isomorphic to the body surface, but magnify behaviorally important skin regions, which include the hands and face in primates, and the whiskers in rodents. Within each map, intracortical circuits process tactile information, mediate spatial integration, and support active sensation. Maps may also contain fine-scale representations of touch submodalities, or direction of tactile motion. Functional representations are more overlapping than suggested by textbook depictions of map topography. The whisker map in rodent somatosensory cortex is a canonic system for studying cortical microcircuits, sensory coding, and map plasticity. Somatosensory maps are plastic throughout life in response to altered use or injury. This chapter reviews basic principles and recent findings in primate, human, and rodent somatosensory maps.
包含体表地形图的体感区域是顶叶皮层的一个主要特征。在灵长类动物中，顶叶皮层包含四个体感区域，每个区域都有自己的地图，其中3b区有主要的皮肤地图。啮齿动物至少有三个顶叶体感区域。这些地图与体表并不同构，而是放大了行为上重要的皮肤区域，在灵长类动物中包括手和脸，在啮齿动物中包括胡须。在每个地图内，皮质内回路处理触觉信息，介导空间整合，并支持主动感觉。地图还可能包含触觉亚模态或触觉运动方向的精细表征。功能表征比教科书中地图地形学的描述所显示的更加重叠。啮齿动物体感皮层中的胡须地图是研究皮层微回路、感觉编码和地图可塑性的典型系统。体感地图在整个生命过程中会因使用改变或损伤而发生可塑性变化。本章回顾了灵长类动物、人类和啮齿动物体感地图的基本原理和最新发现。
