PainActivity-dependent conduction velocity changes of Aδ fibers in a rat model of neuropathyWon, Chung-Kil1; Oh, Seung-Jae2; Jung, Sung-Cherl3; Choi, Young-Ryong2; Kim, Yang-In4; Leem, Joong Woo5; Shin, Hyung-Cheul3,6Author Information 1Departments of Pharmacology, College of Medicine, Korea University, Anam-dong 5 ga, Sungbuk-gu, Seoul Korea, #136-705 2Departments of Anaesthesiology, Hallym University, 1-Ockchundong, Chunchon, Kangwondo, Korea #200-702 3Departments of Physiology, College of Medicine, Hallym University, 1-Ockchundong, Chunchon, Kangwondo, Korea #200-702 4Departments of Physiology, College of Medicine, Korea University, Anam-dong 5 ga, Sungbuk-gu, Seoul Korea, #136–705; 5Department of Physiology, College of Medicine, Yonsei University, Shin Chon, Seoul, Korea 6Corresponding Author: Hyung-Cheul Shin ACKNOWLEDGEMENTS: Supported partially by KOSEF grant No. 94-0403-150-02-3 and by a '97 Basic Medical Science grant from Korean Ministry of Education. Website publication 24 September 1997 Received 24 July 1997; accepted 8 August 1997 NeuroReport: October 20th, 1997 - Volume 8 - Issue 15 - p 3201-3205 Buy Abstract ACTIVITY-DEPENDENT changes of conduction velocity (CV) and conduction block in single Aδ fibers of primary afferent neurons were characterized in a rat model of neuropathy (NP). Injured dorsal root (DR) fiber in NP rats exhibited profoundly greater decreases of CV following impulse activity than did DR fiber in normal rats. Activity-dependent conduction block was absent up to 100 Hz of activity rate in DR fiber of NP rats, but was present above 25 Hz in normal rats. Profiles of activity dependence in sciatic fibers were similar in both NP and normal rats. These results suggest that nerve injury may alter activity-dependent hypoexcitability of Aδ DR fibers. Furthermore, this excitability change may be responsible for the elevated pain perception in neuropathy. © Lippincott-Raven Publishers.