ACTIVITY-DEPENDENT CONDUCTION LATENCY CHANGES IN A-BETA FIBERS OF NEUROPATHIC RATS

ACTIVITY-DEPENDENT changes of the conduction latency of single A beta fibers of primary afferent neurons were characterized in both neuropat hic (L4 and L6 ligated) and normal rats. Activity-dependent increases in conduction latency of dorsal root fibers in neuropathic rats were s ignificantly stronger than those in normal rats. Different profiles of activity dependence were also observed between injured and adjacent i ntact dorsal root fibers of neuropathic rats. However, activity-depend ent latency changes in sciatic nerves distal to the dorsal root gangli on were not different between neuropathic and normal rats. These resul ts suggest that partial nerve injury induces activity-dependent excita bility changes in the dorsal root fibers of neuropathic rat and that t hese changes may be responsible for the altered sensory processing suc h as those seen in allodynia.