A single intrathecal injection of GABA permanently reverses neuropathic pain after nerve injury.

To investigate whether neuropathic pain is sensitive to spinal GABA levels, GABA was injected intrathecally after nerve injury and sensory behaviors were evaluated. Both thermal and tactile hypersensitivities were permanently reversed at the highest doses of GABA. However, if GABA was injected any later than 2-3 weeks after nerve injury, it was ineffective to prevent such hypersensitivity. This suggests that altered spinal GABA levels contribute to the induction phase of chronic neuropathic pain and that early intervention to restore GABA may prevent the development of that pain.