Bannister Kirsty, Dickenson Anthony H
Department Neuroscience, Physiology and Pharmacology, University College London, London, UK.
Curr Opin Support Palliat Care. 2016 Jun;10(2):143-8. doi: 10.1097/SPC.0000000000000207.
Here, we give a topical overview of the ways in which brain processing can alter spinal pain transmission through descending control pathways, and how these change in pain states. We link preclinical findings on the transmitter systems involved and discuss how the monoamines, noradrenaline, 5-hydroxytryptamine (5-HT), and dopamine, can interact through inhibitory and excitatory pathways.
Descending pathways control sensory events and the actions of the neurotransmitters noradrenaline and 5-HT in the dorsal horn of the spinal cord are chiefly implicated in nociception or antinociception according to the receptor that is activated. Abnormalities in descending controls effect central pain processing. Following nerve injury a noradrenaline-mediated control of spinal excitability is lost, whereas its restoration reduces neuropathic hypersensitivity. The story with 5-HT remains more complex because of the myriad of receptors that it can act upon; however the most recent findings support that facilitations may dominate over inhibitions.
The monoaminergic system can be manipulated to great effect in the clinic resulting in improved treatment outcomes and is the basis for the actions of the antidepressant drugs in pain. Looking to the future, prediction of treatment responses will possible by monitoring a form of inhibitory descending control for optimized pain relief.
在此，我们对大脑处理过程通过下行控制通路改变脊髓疼痛传递的方式以及这些方式在疼痛状态下如何变化进行了专题概述。我们将涉及的递质系统的临床前研究结果联系起来，并讨论单胺类物质、去甲肾上腺素、5-羟色胺（5-HT）和多巴胺如何通过抑制性和兴奋性通路相互作用。
下行通路控制感觉事件，脊髓背角中去甲肾上腺素和5-HT等神经递质的作用主要根据被激活的受体参与伤害感受或抗伤害感受。下行控制异常影响中枢疼痛处理。神经损伤后，去甲肾上腺素介导的对脊髓兴奋性的控制丧失，而其恢复可减轻神经性超敏反应。由于5-HT可作用于众多受体，其情况更为复杂；然而，最新研究结果支持促进作用可能超过抑制作用。
单胺能系统在临床上可被有效调控，从而改善治疗效果，这也是抗抑郁药物治疗疼痛的作用基础。展望未来，通过监测一种抑制性下行控制形式来预测治疗反应，有望实现优化的疼痛缓解。
