Neuronal model of tactile allodynia produced by spinal strychnine: effects of excitatory amino acid receptor antagonists and a μ-opiate receptor agonist

The study investigated the effects of spinal strychnine on tactile allodynia in cats, finding that strychnine enhanced responses to hair deflection and expanded receptive fields in dorsal horn neurons. These effects were countered by NMDA and non-NMDA receptor antagonists, but not by mu-opiate receptor agonists. The results suggested that disinhibition from loss of glycinergic input could be linked to nociceptive states similar to post-nerve injury in humans. The findings indicated that normal afferent input is regulated by glycinergic circuits, and disruption of this regulation amplifies tactile responses, offering insights into potential treatments for pain states resistant to opioids.