Expression of the voltage-gated calcium channels (VGCCs) α2/δ-1 subunit in the lumbar spinal cord. A, The western blot shows an increase in the level of VGCC α2/δ-1 subunit expression in the ipsilateral lumbar spinal dorsal horn at 4 hrs and 4 days after MA (CFA/NS injected into the ankle articular cavity). B, Western blot analysis reveals that repeated Gab treatment significantly suppresses MA-induced upregulation of the VGCC α2/δ-1 subunit in the ipsilateral lumbar spinal dorsal horn. * p < 0.05, ** p < 0.01 vs. control (sham MA or naïve); ++ p < 0.01 vs. MA. C, Immunohistochemistry reveals that the VGCC α2/δ-1 subunits are extensively distributed in the spinal dorsal horn. Double immunofluorescence staining shows that the VGCC α2/δ-1 subunit does not colocalized with the microglial marker Iba-1 or the astrocytic marker GFAP in the spinal dorsal horn. D, Double immunofluorescence staining shows that VGCC α2/δ-1 subunits are colocalized with IB4 in the inner lamina II and CGRP and SP in the lamina I and outer lamina II of the spinal cord.