在针刺镇痛原理研究方面曾有报道认为:丘脑束旁核(Pf)为接受痛觉冲动的结构。其神经元的痛放电可被针刺穴位所抑制。而传导痛觉的 C 类纤维的传入信号

可在皮层引起潜伏期较长的诱发电反应。本实验室也观察到:用2%利多卡因局部阻滞皮层体感(?)区(S(?))或给予 r-氨基The present work was designed to investigate the effects of electroacupuncture(EA)on nociceptive responses in the nucleus parafascicularis (Pf) after topical administraction of GABA on the somatosensory area I (SI)and the precruciate cortex respectively by means of glass microelectrodes to record the activities of Pf neurons extracellalarly.The experiments were carried out on adult cats (2.0—3.5kg) immobilized with gallamine triethiadide. The results were as follows:When the functional state of SI was altered by topical application of GABA

there was no difference in nociceptive responses of Pf neurons before and after EA.However

in the control group with normal saline (NS) there was a significant difference in nociceptive responese before and after EA (P<0.05).Besides

the difference in the effects of EA between GABA+EA group and NS+EA group was statistically significant.Furthermore

using GABA administered on the precurciate cortex

The results were the same as those mentioned above. The data given above show that the SI area and the precruciate cortex are involved in descending modulation of EA effect in the nucleus Pf of the thalamus.