Opioid painkillers like morphine may reshape the nervous system to amplify pain signals, making patients more sensitive to pain. Now an experiment on rats suggests that microglia may be responsible for this phenomenon of opioid-induced hyperalgesia and that it might be reversible.

See the source article by following the link below:
Opioid painkillers like morphine may reshape the nervous system to amplify pain signals, making patients more sensitive to pain. Now an experiment on rats suggests that microglia may be responsible for this phenomenon of opioid-induced hyperalgesia and that it might be reversible.