Background: The neural mechanisms underlying discogenic low back pain caused by disc degeneration remain unclear. Previous studies demonstrated that satellite cells (SC) play an important role in neuropathic pain.
Methods: Twenty adult female Sprague-Dawley rats were used. The rats were divided into two groups: a nucleus pulposus (NP) group whose discs were punctured to expose the NP (n = 10) and a sham-operated group whose annulus fibrosus surface was scratched superficially (n = 10). In this study, we investigated the expression and cellular distribution of glial fibrillary acidic protein (GFAP, a marker of SC activation) in the dorsal root ganglia (DRG) innervating the intervertebral discs using a retrograde tracing method and immunohistochemistry in a disc-punctured rat model.
Results: In the sham-operated group, GFAP-immunoreactive (IR) SCs were not detected. In the NP group, GFAP-IR SC became evident, and 49 ± 13% of neurons innervating the punctured discs were surrounded by GFAP-positive SCs.
Conclusions: Our results were the first to provide evidence for a potential role of SCs in the neural mechanisms of discogenic low back pain caused by disc degeneration.