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Different indentation velocities activate different populations of mechanoreceptors in humans
Author(s) -
Simonetti Stefano,
Dahl Kristian,
Krarup Christian
Publication year - 1998
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/(sici)1097-4598(199807)21:7<858::aid-mus3>3.0.co;2-5
Subject(s) - stimulation , mechanoreceptor , anatomy , electrophysiology , sensory system , chemistry , sensory stimulation therapy , electromyography , sensory nerve , medicine , neuroscience , biology
We have examined whether different skin machanoreceptors are activated by different indentation velocities of a tactile probe. Indentations of 300 μm at velocities of 100 and 400 μm/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 μV, and less than 15% of the CSAPs evoked by electrical stimulation. The areas of the polyphasic tactile CSAPs were 35–38% smaller at 100 μm/ms than at 400 μm/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‐μm/ms tactile stimulation but 11–17% lower at 100‐μm/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 μm/ms but only 14% at 400 μm/ms. These studies suggested that indentation at 400 μm/ms activated mainly deeply placed (Pacini corpuscles) and to some extent superficial mechanoreceptors, whereas the 100‐μm/ms indentation activated primarily superficially situated receptors (Meissner corpuscles, and some slowly adapting units). © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:858–868, 1998.