α2δ-1 dorsal root ganglion spinal cord K-Cl cotransporter-2 (KCC2) synaptic plasticity synaptic transmission Introduction Chronic neuropathic pain is often caused by peripheral nerve injury and certain cancer therapeutics. Both traumatic nerve injury and chemotherapy-induced neuropathy augment glutamate NMDAR activity in the spinal cord dorsal horn, which serves to amplify nociceptive input from primary sensory neurons (Woolf and Salter, 2000; H. Y. Zhou et al., 2011; Deng et al., 2019a).