Electroacupuncture reduced migraine-like pain by suppressing serotonin receptor seven signalling that heightens pain sensitivity in trigeminal pathways.
Researchers induced migraine-like meningeal inflammation in rats by injecting an inflammatory mixture into the dura. They applied electroacupuncture before inflammatory injections and assessed mechanical and temperature-related pain responses, neuronal activity in the trigeminal brainstem region, and molecular changes in trigeminal tissues. They also administered drugs that either activated or blocked serotonin receptor seven and measured receptor expression and associated protein kinase signalling using molecular, protein, imaging, and biochemical methods.
Electroacupuncture improved pain thresholds, reduced excessive spontaneous and stimulus-evoked activity in trigeminal neurons, and lowered serotonin receptor seven expression. Activating this receptor weakened electroacupuncture’s pain-relieving effects and restored activity in protein kinase signalling pathways, whereas blocking the receptor reproduced electroacupuncture’s effects. These findings identify serotonin receptor seven suppression as a key mechanism through which electroacupuncture dampens trigeminal pain sensitisation.
