Central signals rapidly switch tactile processing in rat barrel cortex during whisker movements
Central signals rapidly switch tactile processing in rat barrel cortex during whisker movements
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DOI：
10.1093/cercor/bhj056
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发表时间：
2006-08-01
期刊：
影响因子：
3.7
通讯作者：
Schwarz, Cornelius
中科院分区：
文献类型：
--
作者：
Hentschke, Harald;Haiss, Florent;Schwarz, Cornelius
触觉运动（“主动”触摸）是触觉传感的组成部分。众所周知，触觉信号可以在某些行为环境中被调制，但这种调制与运动学的关系以及它是源于触觉感受器还是来自中枢源仍然没有解决。使用清醒的，头部固定的大鼠，训练接触一个物体，我们精确地测量了肌肉推进的胡须运动的轨迹，并比较了触觉反应，从而实现与“被动”接触（不动的胡须接触的对象）。桶皮层深层的多电极细胞外记录显示，当动物主动移动胡须时，触觉处理从高反应幅度，宽皮层代表和低背景放电切换到低反应幅度，窄空间代表和升高的背景放电。转换是快速的（< 100 ms），与警觉程度无关，如通过接触前场电位的频谱分析所评估的。开关持续时，信息中断中断的胡须运动学的眶下神经和接触模仿外周电刺激。总之，这些特征使得源自运动系统的中枢信号可能对主动触摸的处理有贡献。
Palpatory movements ('active' touch) are an integral part of tactile sensing. It is known that tactile signals can be modulated in certain behavioral contexts, but it is still unresolved to what degree this modulation is related to movement kinematics and whether it stems from tactile receptors or from central sources. Using awake, head-fixed rats, trained to contact an object, we measured trajectories of muscle-propelled whisker movement precisely and compared tactile responses to contacts thus accomplished with 'passive' contacts (motionless whisker contacted by object). Multielectrode extracellular recordings in deep layers of barrel cortex revealed that when the animals moved their whiskers actively, tactile processing switched from high response amplitudes, wide cortical representation and low background firing, to low response amplitudes, narrow spatial representation and elevated background firing. Switching was fast (< 100 ms) and unrelated to the degree of alertness as assessed by spectral analysis of pre-contact field potentials. Switching persisted when information about whisker kinematics was interrupted by transection of the infraorbital nerve and contacts were mimicked by peripheral electrical stimulation. Taken together, these characteristics render central signals derived from the motor system a likely contributor to the processing of active touch.