Neuroscience letters
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Neuroscience letters · Jul 1995
Clinical TrialResponse characteristics of cutaneous mechanoreceptors to vibratory stimuli in human glabrous skin.
We investigated the responsiveness of mechanoreceptors in the glabrous skin of the hand to triangular vibratory stimuli when the frequency and applied pressure to the skin were varied. Using a microneurographic technique, 13 single afferent activities were recorded from 4 kinds of mechanoreceptors. Both fast-adapting (FA) and slow-adapting (SA) units were sensitive to the vibratory stimuli. ⋯ FA-type II (FAII) sensitivity was augmented sharply over 60-100 Hz. SA-type I (SAI) and SA-type II (SAII) responsiveness was almost the same and characteristic sensitivity to the vibratory stimuli was revealed under 15 Hz. Functional roles of these units, especially type I units, are discussed in relation to active touch such as texture discrimination with a finger.
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Neuroscience letters · Jul 1995
Continuous infusion of acidified saline around the rat sciatic nerve produces thermal hyperalgesia.
Recent observations using both clinical and animal models have suggested that acidosis may initiate pain and sensitization. In the present study, we examined if changing the acidic environment around the rat sciatic nerve resulted in thermal hyperalgesia. ⋯ Unbuffered, acidified PFS significantly decreased the perineural pH (pH 6.9 +/- 0.15, P < 0.05), and decreasing perineural pH values were significantly correlated with increasing thermal hyperalgesia (r = 0.91) for individual rats. While it is likely that multiple factors play a role in the development of neuropathic pain, these data demonstrate that an acidic environment around the sciatic nerve will produce thermal hyperalgesia.