家兔脊髓部分切割对电针抑制束旁核痛敏放电的影响

用玻璃微电极在39只1.8～3.0kg的家兔上记录了64个丘脑束旁核神经元对腓总神经强电流刺激的痛敏放电。电针双侧“足三里”区域后,这些神经元的痛敏放电,有的被明显抑制(占48.4％);有的被部分抑制(占18.8％);有的则基本未受影响(占32.8％)。切割脊髓双侧背柱后,16个转经元的痛敏放电和电针抑制效应均无明显变化;切割包括双侧背外侧束在内的背半部后,则11个神经元中有7个的电针抑制效应被明显削弱,而其余4个的电针抑制效应基本无改变。实验结果表明,电针对束旁核痛敏放电的抑制效应,主要是通过背外侧束中的下行纤维实现的。

Effects of Subtotal Transection of the Spinal Cord on Antinociceptive Action of Electroacupuncture in Rabbits

This experiment was designed to localize the fibers winch contributed to the descending inhibitory effects of electroacupuncture (EA) and to show if the fibers in the dorsal column were related to the antinociceptive action of EA on the point "Zousanli" .The results were as follows,1. Nociceptive discharges of most (31/64) of parafascicular (Pf) neurons pro-dueed by stimulating the common peroneal nerve with a stronger electrical current could be partially or profoundly inhibited by EA.2. The transection of the bilateral dorsal column could affect neither the nociceptive discharges nor the antinociceptive action of EA in 16 Pf neurons.3. The transection of the dorsal half of the spinal cord (containing the bilateral dorsal column and dorsal lateral funiculus, DLE) could not change the nociceptive discharges of 11 Pf neurons, but antinociceptive action of EA in 7 of 11 Pf neurons was attenuated by the same treatment, and in other 4 neurons they were not.These results suggest that the antinociceptive action of EA on Pf neurons arc mainly related to the descending fibers in DLF, and have little, if any, relation to the dorsal column in rabbit.