title: Neomycin blocks capsaicin-evoked responses in rat dorsal root ganglion neurons.
abstract: Small dorsal root ganglion (DRG) neurons are characterized by sensitivity to capsaicin. In acutely isolated rat DRG neurons, the effect of neomycin, one of the aminoglycoside antibiotics, on capsaicin-evoked current and voltage responses was examined using whole-cell patch-clamp recording. We showed for the first time that neomycin dose-dependently inhibited capsaicin-evoked currents with half-maximal inhibitory concentration at 130.60 microM (n=70). Under current-clamp condition, depolarization and firing rate evoked by capsaicin became weakened when neomycin was perfused to the neurons (n=10). Neomycin had no significant effect on the resting potentials of DRG neurons. These results suggest that neomycin could inhibit capsaicin-sensitive responses in small DRG neurons, which may contribute to neomycin-induced peripheral analgesia.
authors.affiliation: Institute of Neurobiology, Fu-Dan University, 220 Han-Dan Road, 200433, Shanghai, PR China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.forename: Z S
authors.initials: ZS
authors.lastname: Zhou
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Zhao
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002211:Capsaicin / Q000494:pharmacology*; D005071:Evoked Potentials; D005727:Ganglia, Spinal / Q000166:cytology*; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials; D009355:Neomycin / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000700:Analgesics; D000900:Anti-Bacterial Agents; D009355:Neomycin; D002211:Capsaicin