TO-JUNG TSENG2026-10-162026-10-162008-02-01Pure ID: 15339324Pure UUID: c239f74a-7a97-4663-92cd-9f6d476192eb10.1097/nen.0b013e3181630bb8https://www.scopus.com/pages/publications/42949122538https://scholars.csmu.edu.tw/handle/123456789/28180To generate an experimental neuropathy model in which smalldiameter sensory nerves are specifically affected and to test a potential treatment, adult mice were given a single injection (50 μg/kg, i.p.) of the capsaicin analog resiniferatoxin (RTX). On Day 7 after RTX treatment, there was a 53% reduction in unmyelinated nerve density in the medial plantar nerve (p = 0.0067) and a 66% reduction in epidermal nerve density of hind paw skin (p = 0.0004) compared with vehicle-treated controls. Substance PYimmunoreactive dorsal root ganglion neurons were also markedly depleted (p = 0.0001). These effects were associated with the functional deficit of prolonged withdrawal latencies to heat stimuli (p = 0.0007) on a hot plate test. The potential therapeutic effects of 4-methylcatechol (4MC) on this neuropathy were then tested by daily injections of 4MC (10 μg/kg,i.p.) from Days 7 to 35 after neuropathy induction. On Day 35, 4MCtreated mice had an increase in unmyelinated (p = 0.014) and epidermal nerve (p = 0.0013) densities and a reduction in thermal withdrawal latency (p = 0.0091) compared with RTX-only controls. These results indicate that 4MC promoted regeneration of unmyelinated nerves in experimental RTX-induced neuropathy and enhanced function.12enjournal article