Erratum to “Partial nerve injury induces electrophysiological changes in conducting (uninjured) nociceptive and non-nociceptive DRG neurons: Possible relationships to aspects of peripheral neuropathic pain and paresthesias” [Pain 153 (9) (2012) 1824–1836]

Partial nerve injury leads to peripheral neuropathic pain. This injury results in conducting/uninterrupted (also called uninjured) sensory fibres, conducting through the damaged nerve alongside axotomised/degenerating fibres. In rats seven days after L5 spinal nerve axotomy (SNA) or modified-SNA (added loose-ligation of L4 spinal nerve with neuroinflammation-inducing chromic-gut), we investigated (a) neuropathic pain behaviours and (b) electrophysiological changes in conducting/uninterrupted L4 dorsal root ganglion (DRG) neurons with receptive fields (called: L4-receptive-field-neurons). Compared to pretreatment, modified-SNA rats showed highly significant increases in spontaneous-footlifting duration, mechanical-hypersensitivity/allodynia, and heathypersensitivity/hyperalgesia, that were significantly greater than 0304-3959 2012 International Association for the Study of Pain. Published by Elsevie http://dx.doi.org/10.1016/j.pain.2012.08.010 DOI of original article: http://dx.doi.org/10.1016/j.pain.2012.04.019 ⇑ Corresponding author. E-mail address: [email protected] (S.N. Lawson). after SNA, especially spontaneous-foot-lifting. We recorded intracellularly in vivo from normal L4/L5 DRG neurons and ipsilateral L4-receptive-field-neurons. After SNA or modified-SNA, L4-receptive-field-neurons showed the following: (a) increased percentages of C-, Ad-, and Ab-nociceptors and cutaneous Aa/b-low-threshold mechanoreceptors with ongoing/spontaneous firing; (b) spontaneous firing in C-nociceptors that originated peripherally; this was at a faster rate in modified-SNA than SNA; (c) decreased electrical thresholds in A-nociceptors after SNA; (d) hyperpolarised membrane potentials in A-nociceptors and Aa/b-low-thresholdmechanoreceptors after SNA, but not C-nociceptors; (e) decreased somatic action potential rise times in Cand A-nociceptors, not Aa/b-low-threshold-mechanoreceptors. We suggest that these changes in subtypes of conducting/uninterrupted neurons after partial nerve injury contribute to the different aspects of neuropathic pain as follows: spontaneous firing in nociceptors to ongoing/spontaneous pain; spontaneous firing in Aa/b-lowthreshold-mechanoreceptors to dysesthesias/paresthesias; and lowered A-nociceptor electrical thresholds to A-nociceptor sensitization, and greater evoked pain. r B.V. Open access under CC BY license.