An anatomical and immunohistochemical characterization of afferents innervating the C6-C7 facet joint after painful joint loading in the rat.
An anatomical and immunohistochemical characterization of afferents innervating the C6-C7 facet joint after painful joint loading in the rat.
复制标题
大鼠疼痛的关节载荷后，对C6-C7小平面关节的神经传入的解剖和免疫组织化学表征。
DOI：
10.1097/brs.0b013e318285b5bb
复制
发表时间：
2013-03-15
期刊：
影响因子：
3
通讯作者：
Winkelstein BA
中科院分区：
文献类型：
--
作者：
Kras JV;Tanaka K;Gilliland TM;Winkelstein BA
This study used retrograde neuronal tracing and immunohistochemistry to identify neurons innervating the C6/C7 facet joint and those expressing calcitonin gene-related peptide (CGRP) in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. The objective of this study was to characterize the innervation of the C6/C7 facet joint after painful joint injury in the rat. The cervical facet joint is a source of neck pain, and its loading can initiate persistent pain. CGRP is a nociceptive neurotransmitter; peptidergic afferents have been identified in the facet joint’s capsule. Although studies suggest that facet joint injury alters CGRP expression in joint afferents, the distribution of neurons innervating the C6/C7 facet joint and their expression of CGRP after a painful joint injury have not been investigated. Holtzman rats received an intra-articular injection of cholera toxin subunit B (CTb) in the C6/C7 facet joints. After injection, subgroups underwent either a painful joint distraction or sham procedure. Mechanical sensitivity was assessed, and immunohistochemical techniques were utilized to quantify CGRP expression and CTb labeling in the C5-C8 DRGs. Facet joint distraction induced (p≤0.0002) hypersensitivity. Neurons labeled by the joint injection were identified in the C5-C8 DRGs. Significantly more (p≤0.0001) CTb-positive neurons were identified in the C7 DRG than any other level. At C7, 54.4±15.3% of those neurons were also CGRP-positive, whereas only 41.5±5.4% of all neurons were CGRP-positive; this difference was significant (p=0.0084). The greatest number of afferents from the C6/C7 facet joint has cell bodies in the C7 DRG, implicating this level as the most relevant for pain from this joint. In addition, peptidergic afferents appear to have an important role in facet joint-mediated pain.
