Increased Na+ and K+ currents in small mouse dorsal root ganglion neurons after ganglion compression

• DOI: 10.1152/jn.00065.2011
• Publication Date: 2011-04-27T22:57:09Z
• Authors: Ni Fan; Parul Sikand; David F. Donnelly; Chao Ma; Robert H. LaMotte
• Keywords: Dorsal root ganglion; Rheobase; Current clamp

We investigated the effects of chronic compression (CCD) L3 and L4 dorsal root ganglion (DRG) on pain behavior in mouse electrophysiological properties small-diameter neuronal cell bodies intact ganglion. CCD is a model human radicular produced by intraforaminal stenosis other disorders affecting DRG, spinal nerve, or root. On days 1, 3, 5, 7 after onset compression, there was significant decrease from preoperative values threshold mechanical force required to elicit withdrawal foot ipsilateral (tactile allodynia). Whole patch-clamp recordings were obtained, vitro, small-sized somata and, for first time, DRG. Under current clamp, neurons exhibited significantly lower rheobase compared with controls. A few but no control spontaneous action potentials. showed an increase density TTX-resistant TTX-sensitive Na(+) current. also enhanced voltage-dependent K(+) current, due delayed rectifier without change transient "A" conclude that produces pain, as we have previously demonstrated rat. While role remains be elucidated, speculate it represents compensatory response reduce ectopic aberrant levels activity injury.