
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]
Author(s) -
Laiche Djouhri,
Xin Fang,
Stella Koutsikou,
Sally N. Lawson
Publication year - 2012
Publication title -
pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.524
H-Index - 258
eISSN - 1872-6623
pISSN - 0304-3959
DOI - 10.1016/j.pain.2012.08.010
Subject(s) - nociceptor , nociception , receptive field , neuropathic pain , electrophysiology , medicine , neuroscience , peripheral nerve injury , nerve injury , hyperalgesia , dorsal root ganglion , allodynia , anesthesia , sensory system , sciatic nerve , psychology , receptor
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-foot-lifting duration, mechanical-hypersensitivity/allodynia, and heat-hypersensitivity/hyperalgesia, that were significantly greater than 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-, Aδ-, and Aβ-nociceptors and cutaneous Aα/β-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 Aα/β-low-threshold-mechanoreceptors after SNA, but not C-nociceptors; (e) decreased somatic action potential rise times in C- and A-nociceptors, not Aα/β-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 Aα/β-low-threshold-mechanoreceptors to dysesthesias/paresthesias; and lowered A-nociceptor electrical thresholds to A-nociceptor sensitization, and greater evoked pain.