Simonetti S, Dahl K, Krarup C
Department of Clinical Neurophysiology NF3063, Copenhagen University Hospital (Rigshospitalet), Denmark.
Muscle Nerve. 1998 Jul;21(7):858-68. doi: 10.1002/(sici)1097-4598(199807)21:7<858::aid-mus3>3.0.co;2-5.
We have examined whether different skin machanoreceptors are activated by different indentation velocities of a tactile probe. Indentations of 300 microns at velocities of 100 and 400 microns/ms were applied at the dorsolateral side of the foot and at the tip of digit III. Compound sensory action potentials (CSAPs) were recorded from the sural and median nerves, respectively. The amplitudes of the tactile CSAPs were < 1-2 muV, and less than 15% of the CSAPs evoked by electrical stimulation. The areas of the polyphasic tactile CSAPs were 35-38% smaller at 100 microns/ms than at 400 microns/ms. The maximal sensory nerve conduction velocities (SNCVs) were higher in the median than in the sural nerves. In both nerves, the SNCVs were similar at electrical and 400-micron/ms tactile stimulation but 11-17% lower at 100-micron/ms stimulation. Cocaine hydrochloride was applied iontophoretically at the dorsolateral side of the foot, causing a decrease of 50% of the CSAP evoked by 100 microns/ms but only 14% at 400 microns/ms. These studies suggested that identation at 400 microns/ms activated mainly deeply placed (Pacini corpuscles) and to some extent superficial mechanoreceptors, whereas the 100-micron/ms indentation activated primarily superficially situated receptors (Meissner corpuscles, and some slowly adapting units).
我们研究了不同的皮肤机械感受器是否会被触觉探针的不同压痕速度所激活。在足背外侧和第三指指尖处以100和400微米/毫秒的速度施加300微米的压痕。分别从腓肠神经和正中神经记录复合感觉动作电位（CSAPs）。触觉CSAPs的振幅<1 - 2微伏，且小于电刺激诱发的CSAPs的15%。多相触觉CSAPs的面积在100微米/毫秒时比在400微米/毫秒时小35 - 38%。正中神经的最大感觉神经传导速度（SNCVs）高于腓肠神经。在两条神经中，电刺激和400微米/毫秒触觉刺激时的SNCVs相似，但在100微米/毫秒刺激时低11 - 17%。将盐酸可卡因通过离子电渗法施加于足背外侧，导致100微米/毫秒诱发的CSAP降低50%，但在400微米/毫秒时仅降低14%。这些研究表明，400微米/毫秒的压痕主要激活深层放置的（帕西尼小体）并在一定程度上激活浅层机械感受器，而100微米/毫秒的压痕主要激活浅层的感受器（迈斯纳小体和一些慢适应单位）。
