Experimental Research PARTICIPATION OF GABA IN SH EMANATING DESCENDING MODULATION ON THE NUCLEUS CENTRUM MEDIANUM VIA MOTOR CORTEX IN ACUPUNCTURE ANALGESIA

摘要

The effects of electrical stimulation of second somatosensory area(S Ⅱ)andelectroacupuncture(EA)at Huantiao(GB 30)and Yanglinquan(GB 34)points on nociceptive re-sponses of neurons in the nucleus centrum medianum(CM)in the thalamus were respectively ob-served after topical application of bicuculline(Bic)at the motor cortex(MCtx),and the results werecompared with those obtained in the saline control group.It was found that following application ofBic either electrical stimulation of SII(n=11)or EA(n=11)yielded obvious inhibition on nocicep-tive responses of CM neurons(P0.05),which was similar to the inhibitory effects obtained in thesaline control groups(n=11,n=10).After GABA application at MCtx electrical stimulation of SIIfailed to show inhibition on nociceptive responses in 3 CM neurons.It is indicated that GABA in MC-tx is involved in SII originating corticofugal regulation of nucleus CM in acupuncture analgesia.