ANATOMY AND PHYSIOLOGY OF A NOCICEPTIVE MODULATORY SYSTEM
ANATOMY AND PHYSIOLOGY OF A NOCICEPTIVE MODULATORY SYSTEM
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DOI：
10.1098/rstb.1985.0037
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发表时间：
1985-01-01
期刊：
影响因子：
--
通讯作者：
HEINRICHER, MM
中科院分区：
文献类型：
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作者：
FIELDS, HL;HEINRICHER, MM
尽管感觉传递的传出控制是一个公认的概念，但直到最近才发现伤害性调节的特定网络。该网络包括中脑、延髓和脊髓水平的相互连接的组件。在中脑水平，电刺激中脑导水管周围灰质（p.a.g.）抑制对伤害性刺激以及伤害感受器诱导的反射和多种物种中的逃避行为作出反应的脊髓神经元。中脑刺激还可用于临床显著疼痛患者的镇痛。延髓头端腹侧区（r.v.m.）具有类似的行为和生理作用，并在脊髓水平介导中脑抗伤害感受作用。内啡肽存在于这个伤害性调节网络的所有水平。麻醉前微量注射鸦片相对运动量或脊髓水平产生镇痛，大概是通过模仿内啡肽的作用。伤害性调节系统是弥散组织的，高度互连的，并且似乎作为一个单元，无论是由阿片类药物还是电刺激激活。有两类r.v.m.神经元，其活动与由伤害性刺激诱导的反射的发生相关。一类（开细胞）加速，另一类（关细胞）在甩尾前暂停。这两类都投射到脊髓，并通过中脑的电刺激而兴奋。然而，当吗啡被全身注射或注射到p.a.g.时，关闭电池被激励，开启电池停止激发。离网的可能是r.v.m.在脊髓水平抑制伤害性传递的输出细胞。on-cell的功能尚不清楚。伤害性调节系统可以被各种应激环境因素激活，这些因素通常但不一定是有害的。认为该系统是一个简单的负反馈电路的想法与其已知的性质不一致。
Although efferent control of sensory transmission is a well-established concept, a specific network for nociceptive modulation has only recently been discovered. This network includes interconnected components at midbrain, medullary and spinal levels. At the midbrain level, electrical stimulation of the periaqueductal grey (p.a.g.) inhibits spinal neurons that respond to noxious stimuli as well as nociceptor-induced reflexes and escape behaviour in a variety of species. Midbrain stimulation also produces analgesia in patients with clinically significant pain. The rostral ventral medulla (r.v.m.) has similar behavioural and physiological effects and mediates midbrain antinociceptive actions at the level of the spinal cord. Endorphins are present at all levels of this nociceptive modulating network. Opiate microinjections at p.a.g., r.v.m. or spinal levels produce analgesia, presumably by mimicking the actions of the endorphins. The nociceptive modulatory system is diffusely organized, highly interconnected and appears to act as a unit whether activated by opiates or electrical stimulation. There are two classes of r.v.m. neurons the activity of which is correlated with the occurrence of reflexes induced by noxious stimulation. One class (the on-cell) accelerates, the other class (the off-cell) pauses just before tail flick. Both classes project to the spinal cord and are excited by electrical stimulation of the midbrain. However, when morphine is injected either systemically or into the p.a.g., the off-cell is excited and the on-cell stops firing. The off-cell is probably the r.v.m. output cell that inhibits nociceptive transmission at the level of the spinal cord. The function of the on-cell is not clear. The nociceptive modulatory system can be activated by a variety of stressful environmental factors, which are often, but not necessarily, noxious. The idea that the system acts as a simple negative feedback circuit is not consistent with its known properties.