Jordan L M, Kenshalo D R, Martin F R, Haber L H, Willis W D
Marine Biomedical Institute, University of Texas Medical Branch, Galveston, Texas 77550 U.S.A. Department of Physiology, University of Manitoba, Winnipeg R3E OW3 Canada.
Pain. 1978 Aug;5(2):135-142. doi: 10.1016/0304-3959(78)90035-0.
The effects of iontophoretic applications of 5-hydroxytryptamine (5-HT) were tested upon primate spinothalamic tract neurons recorded extracellularly in the spinal cord of anesthetized monkeys. The activity of most high threshold and wide dynamic range spinothalamic tract cells was depressed. 5-HT also reduced the responses of the cells to glutamate pulses which by themselves had a powerful excitatory action. It is concluded that 5-HT has a depressant action upon the postsynaptic membranes of spinothalamic tract cells, although the action has a slow time course. The observations are consistent with, but by no means prove, the hypothesis that serotonergic pathways descending from the brain stem produce a postsynaptic inhibiton of spinothalamic tract neurons.
在麻醉猴脊髓中对细胞外记录的灵长类动物脊髓丘脑束神经元进行了离子电渗法应用5-羟色胺(5-HT)的效果测试。大多数高阈值和宽动态范围的脊髓丘脑束细胞的活性受到抑制。5-HT还降低了细胞对谷氨酸脉冲的反应,而谷氨酸脉冲本身具有强大的兴奋作用。得出的结论是,5-HT对脊髓丘脑束细胞的突触后膜具有抑制作用,尽管该作用具有缓慢的时程。这些观察结果与脑干下行的5-羟色胺能通路对脊髓丘脑束神经元产生突触后抑制的假说一致,但绝不能证明该假说。