RT Journal Article
SR Electronic
T1 Human Foot Outperforms the Hand in Mechanical Pain Discrimination
JF eneuro
JO eNeuro
FD Society for Neuroscience
SP ENEURO.0412-23.2024
DO 10.1523/ENEURO.0412-23.2024
VO 11
IS 2
A1 Ng, Kevin K. W.
A1 Lafee, Odai
A1 Bouchatta, Otmane
A1 Makdani, Adarsh D.
A1 Marshall, Andrew G.
A1 Olausson, Håkan
A1 McIntyre, Sarah
A1 Nagi, Saad S.
YR 2024
UL http://www.eneuro.org/content/11/2/ENEURO.0412-23.2024.abstract
AB Tactile discrimination has been extensively studied, but mechanical pain discrimination remains poorly characterized. Here, we measured the capacity for mechanical pain discrimination using a two-alternative forced choice paradigm, with force-calibrated indentation stimuli (Semmes–Weinstein monofilaments) applied to the hand and foot dorsa of healthy human volunteers. In order to characterize the relationship between peripheral nociceptor activity and pain perception, we recorded single-unit activity from myelinated (A) and unmyelinated (C) mechanosensitive nociceptors in the skin using microneurography. At the perceptual level, we found that the foot was better at discriminating noxious forces than the hand, which stands in contrast to that for innocuous force discrimination, where the hand performed better than the foot. This observation of superior mechanical pain discrimination on the foot compared to the hand could not be explained by the responsiveness of individual nociceptors. We found no significant difference in the discrimination performance of either the myelinated or unmyelinated class of nociceptors between skin regions. This suggests the possibility that other factors such as skin biophysics, receptor density or central mechanisms may underlie these regional differences.