International School for Advanced Studies, Italy.
Curr Opin Neurobiol. 2010 Jun;20(3):319-27. doi: 10.1016/j.conb.2010.03.004. Epub 2010 Apr 18.
Texture sensation in primates, through the fingertips, and in rats, through the whiskers, is rapid and accurate. Recent work has provided enough knowledge to allow comparison of the mechanisms. In primates, coarse textures are sensed through a spatial signal - increasing roughness leads to greater contrast in firing among neurons with nearby receptive fields. Fine textures are sensed by a motion signal - when the fingertip translates across the surface, excitation of rapidly adapting receptors varies according to texture. In rats, passage of a whisker over a surface leads to a motion signal that varies according to roughness. Motion is converted to neuronal spike trains, with progressively rougher surfaces leading to progressively greater firing rates. The extraction of texture by the whiskers shares basic features with the motion-based mechanism in primates. Spatial relationships among whiskers may serve purposes other than texture.
灵长类动物通过指尖、老鼠通过胡须感知纹理的速度非常快且准确。最近的研究提供了足够的知识来比较这些机制。在灵长类动物中，粗糙的纹理通过空间信号感知——粗糙度的增加会导致具有邻近感受野的神经元的放电对比度更大。精细纹理通过运动信号感知——当指尖在表面上平移时，快速适应感受器的兴奋会根据纹理而变化。在老鼠中，当胡须经过表面时，会产生一种根据粗糙度而变化的运动信号。运动被转换为神经元的尖峰脉冲序列，表面越粗糙，发射率就越高。胡须提取纹理的方式与灵长类动物基于运动的机制具有基本特征。胡须之间的空间关系可能除了纹理还有其他用途。
