Abstract
It remains unclear which nerve fibers are responsible for mediating hyperalgesia after skin injury. Here, we examined the role of Ad and C fibers in inflammatory hyperalgesia after a first-degree burn injury. A CO2 laser delivered ultrafast short constant-temperature heat pulses to the upper part of the lower leg to stimulate selectively the relatively fast-conducting thinly myelinated Ad and the slowly conducting unmyelinated C fibers. Participants were asked to respond as fast as possible whenever they detected a thermal stimulus. Thresholds and reaction times to selective Ad and C fiber activations were measured in the conditioned and the surrounding intact skin, at pre-injury, and 1 hour and 24 hours after injury. First-degree burn injury caused a significant decrease in Ad fiber detection thresholds and a significant increase in the proportion of Ad-fiber-mediated responses in the inflamed area 24 hours, but not 1 hour, after burn injury. No changes in heat perception were observed in the intact skin surrounding the injury. No group differences in C-fiber-mediated sensations were observed. Our findings indicate that quickly adapting Ad fibers but not quickly adapting C fibers are sensitized when activated by short and ultrafast heat stimuli after skin burn injury. Our results further show that this change occurs between 1 hour and 24 hours after injury and that it does not extend to the skin surrounding the injury.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Pain |
| Vol/bind | 159 |
| Udgave nummer | 11 |
| Sider (fra-til) | 2331-2338 |
| Antal sider | 8 |
| ISSN | 0304-3959 |
| DOI | |
| Status | Udgivet - nov. 2018 |