Lopez-Garcia José A
Department of Physiology, University of Alcala, 28804, Madrid, Spain.
Curr Top Med Chem. 2006;6(18):1987-96. doi: 10.2174/156802606778522159.
The role of serotonin (5-HT) as a mediator of the endogenous pain control system has been investigated over the last 30 years. Here we review a subset of studies that used electrophysiological techniques to study the mechanisms of action as well as the receptors mediating the spinal effects of serotonin. The works herein discussed employed in vivo or in vitro preparations of control or hyperalgesic animals. According to these reports, 5-HT triggers depressant effects on synaptic transmission limiting the release of neurotransmitters from afferent terminals or the responsiveness of NMDA receptors located in dorsal horn neurones. These mechanisms are most likely mediated by 5-HT1 receptors. In contrast, 5-HT2 receptors seem to mediate excitatory effects such as depolarisation, increased excitability, and neurotransmitter release. The role of 5-HT3 receptors is less clear as they could mediate excitatory or inhibitory effects, depending on variables such as concentration of 5-HT or the state (sensitised/unsensitised) of the spinal cord. The consequences of these spinal effects of serotonin are discussed in the context of pain and analgesia.
在过去30年里，人们一直在研究血清素（5-羟色胺，5-HT）作为内源性疼痛控制系统介质的作用。在此，我们回顾了一部分研究，这些研究使用电生理技术来研究血清素的作用机制以及介导其脊髓效应的受体。本文讨论的研究采用了对照或痛觉过敏动物的体内或体外实验制剂。根据这些报告，5-HT对突触传递产生抑制作用，限制了传入神经末梢神经递质的释放或背角神经元中NMDA受体的反应性。这些机制很可能由5-HT1受体介导。相比之下，5-HT2受体似乎介导兴奋作用，如去极化、兴奋性增加和神经递质释放。5-HT3受体的作用尚不太明确，因为它们可能介导兴奋或抑制作用，这取决于5-HT浓度或脊髓状态（致敏/未致敏）等变量。本文在疼痛和镇痛的背景下讨论了血清素这些脊髓效应的后果。
