The excitatory effects of the chemokine CCL2 on DRG somata are greater after an injury of the ganglion than after an injury of the spinal or peripheral nerve.

We compared the expression of chemokine receptor CCR2 protein in the dorsal root ganglia (DRG) injured by the chronic constriction injury (CCI), the spinal nerve ligation (SNL) and a chronic compression of DRG (CCD). Each of these injuries produced the same significant increase in CCR2 protein in the DRG, as assessed by Western blot analyses. Whole-cell patch-clamp recordings revealed that CCL2, a ligand for CCR2 receptor, depolarized nociceptive DRG neurons from rats of the all three models.