Saito K, Ito S, Kitazawa T, Ohga A
Brain Res. 1982 Nov 11;251(1):117-25. doi: 10.1016/0006-8993(82)91279-3.
In the isolated spinal cord of the newborn rat, methysergide and LSD-25 depressed the monosynaptic reflex discharge selectively. Cyproheptadine and dimethothiazine did not inhibit the monosynaptic reflex. The selective inhibitory effect of methysergide on the monosynaptic reflex was not due to a presumptive low safety factor of this reflex. The inhibition was restored under a condition such as the compound action potential in the dorsal root was enhanced by 4-aminopyridine. Methysergide did not decrease the sensitivity of the motoneuron to substance P and L-glutamic acid. It is suggested that methysergide acts at the presynaptic terminal of Ia afferent fibers and depresses evoked transmitter release.
在新生大鼠的离体脊髓中，麦角新碱和麦角酸二乙酰胺（LSD-25）选择性地抑制单突触反射放电。赛庚啶和二甲替嗪不抑制单突触反射。麦角新碱对单突触反射的选择性抑制作用并非由于该反射假定的低安全系数。在诸如4-氨基吡啶增强背根复合动作电位的条件下，抑制作用得以恢复。麦角新碱不会降低运动神经元对P物质和L-谷氨酸的敏感性。提示麦角新碱作用于Ia传入纤维的突触前终末并抑制诱发的递质释放。
