CHANGES OF µ OPIOID RECEPTOR BINDING SITES IN RAT BRAIN FOLLOWING ELECTROACUPUNCTURE

Abstract

With [³H]-ohmefentanyl as a ligand, autoradiographic technique was used to observe the effect of electroacupuncture (EA) on µ opioid receptor binding sites in the brain areas related to pain modulation. The results were as follows: (1) The distribution of the u receptor in the rat central nervous system was consistent in general with the results reported previously. (2) After EA of Tsu-San-Li, the µ receptor binding sites were increased significantly in the following examined structures: the caudate nucleus, septal nucleus, medial preoptic area, amygdalaoid nucleus, periaqueducal gray, interpeduncular nucleus, nucleus raphe magnus, and cervical and lumbar enlargements. The results indicate that EA is able to increase µ binding sites in the brain areas related to analgesia, suggesting the enhancement of µ receptor function by EA.