Both peripheral nerve injury and chronic opioid treatment can result in hyperalgesia
associated with enhanced excitatory neurotransmission at the level of the spinal cord.
Chronic opioid administration leads to a shift in μ-opioid receptor (MOR)–G protein coupling
from Gi/o to Gs that can be prevented by cotreatment with an ultra-low-dose opioid
antagonist. In this study, using lumbar spinal cord tissue from rats with L5/L6 spinal nerve
ligation (SNL), we demonstrated that SNL injury induces MOR linkage to Gs in the damaged …