The elucidation of role of motor neurons or pain pathways of the spinal cord in analgesia, muscle reluxation, and immobility as general anesthetic factors

本文研究了脊髓P物质(SP)作为全身麻醉因素之一在不动中的作用。右旋美托咪定和吗啡抑制脊髓初级传入神经元的SP释放。已知的选择性N-甲基-D-天冬氨酸(NMDA)通道阻滞剂MK-801可以不引起翻正反射(LORR)的丧失，并刺激啮齿动物的儿茶酚胺能神经元，在觉醒过程中发挥关键作用。MK-801与小剂量的多巴胺(DA)受体拮抗剂氟哌啶醇联合使用，可剂量依赖性地产生LOR，但不能固定。在MK-801加氟哌啶醇治疗的动物中，右美托咪定和吗啡引起不动，然后失去了翻正反射。这些结果表明，这种不动状态与脊髓内SP释放的抑制有关。

The role of substance P (SP) of the spinal cord in immobility as one of the general anesthetic factors was studied. Dexmedetomidine and morphine inhibit SP release from primary afferent neurons in the spinal cord. The selective N-methyl-D-aspartate (NMDA) channel blocker MK-801 is known to induce no loss of the righting reflex (LORR) and to stimulate catecholaminergic neurons in rodents, playing a crucial role in arousal. MK-801 in combination with a small dose of the dopamine (DA) receptor antagonist haloperidol dose-dependently produced LORR, but not immobility. Dexmedetomidine and morphine induced immobility in animals treated with MK-801 plus haloperidol, which then lost their righting reflex. These findings suggest that the immobility involves the inhibition of SP release in the spinal cord.