We studied the topographical distribution of laser sensory thresholds on the human hairy skin, using a small laser beam for pinprick and a large beam for warmth sensations. The threshold for pinprick sensation correlated positively with the distance from the brain, suggesting that A delta nociceptors, the fibers which convey pinprick sensation, are more dense at proximal than at distal body sites. This finding adds information to skin biopsy studies of epidermal free nerve endings which showed a similar gradient, but could not differentiate small myelinated from unmyelinated fiber afferents. Possibly because of a diffuse low density of warmth receptors, laser warmth thresholds showed no trend. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
Topographical distribution of pinprick and warmth thresholds to CO2 laser stimulation on the human skin / R., Agostino; Cruccu, Giorgio; G., Iannetti; A., Romaniello; Truini, Andrea; Manfredi, Mario. - In: NEUROSCIENCE LETTERS. - ISSN 0304-3940. - 285:2(2000), pp. 115-118. [10.1016/s0304-3940(00)01038-7]
Topographical distribution of pinprick and warmth thresholds to CO2 laser stimulation on the human skin
CRUCCU, Giorgio;TRUINI, ANDREA;MANFREDI, Mario
2000
Abstract
We studied the topographical distribution of laser sensory thresholds on the human hairy skin, using a small laser beam for pinprick and a large beam for warmth sensations. The threshold for pinprick sensation correlated positively with the distance from the brain, suggesting that A delta nociceptors, the fibers which convey pinprick sensation, are more dense at proximal than at distal body sites. This finding adds information to skin biopsy studies of epidermal free nerve endings which showed a similar gradient, but could not differentiate small myelinated from unmyelinated fiber afferents. Possibly because of a diffuse low density of warmth receptors, laser warmth thresholds showed no trend. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.