Organization of hyperactive microglial cells in trigeminal spinal subnucleus caudalis and upper cervical spinal cord associated with orofacial neuropathic pain

► Infraorbital nerve injury induced mechanical allodynia of orofacial skin. ► Microglial cells were activated in Vc and C1 after infraorbital nerve injury. ► Inhibition of the microglial cell activation decreased the mechanical allodynia. ► Inhibition of the microglial cell activation decreased neuronal excitability. ► Microglial cell activation plays a role in mechanical allodynia of orofacial skin.