Brain research. Molecular brain research
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Brain Res. Mol. Brain Res. · Mar 2002
Induction of connexin 37 expression in a rat model of neuropathic pain.
Activation of cutaneous C-fibers by capsaicin or sciatic nerve transection increases the number of astrocytic gap junctions as well as the levels of connexin 43 in the dorsal horn on the stimulated side. Changes in connexin 37 mRNA expression following nerve injury have not been previously documented. We examined the role of gap junction protein connexin 37 in neuropathic hypersensitivity following peripheral nerve injury. ⋯ Sciatic nerve connexin 37 mRNA increases were proportional to the extent of thermal hyperalgesia, but skin, muscle, and lumbar spinal cord connexin 37 mRNA showed no significant changes. Neuropathic pain relief correlated with downregulation of connexin 37 mRNA. Results indicate that upregulation of connexin 37 mRNA following sciatic nerve injury correlates with subsequent thermal hyperalgesia, which suggests that gap junctions (connexin 37) are responsible for the hyperexcitability following peripheral nerve injury.