Spinal presynaptic inhibition in pain control.

•Spinal disinhibition contributes to chronic pain after tissue or nerve injury.•Both pre- and postsynaptic inhibition contributes to spinal pain control.•After nerve injury, loss of presynaptic inhibition produces heat hyperalgesia.•After tissue injury, most likely, a switch of presynaptic inhibition into excitation leads to tactile allodynia.