In order to confirm the idea that the cerebral cortex is involved in acupuncture analgesiathrough descending modulation

the effects of stimulation of SmI and electroacupuncture on noci-ceptive responses of VB neurons were investigated.The experiments were carried out on lightlyanesthetized rats.Single unit activities of VB neurons were extracellularly recorded with glassmicroelectrodes.The results showed that both electrical stimulation of SmI(n=11)and electroacupuncture atleft.“Huantiao”(G30)point(n=11)could inhibit the nociceptive responses of VB neurons andtheir effects were similar.These results suggested that SmI may play a role in acupuncture anal-gesia through corticofugal modulation on VB.