Department of Neuroscience, Physiology and Pharmacology, UCL, London, WC1E 6BT, UK.
Department of Neuroscience, Max-Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany.
Sci Rep. 2017 May 22;7(1):2215. doi: 10.1038/s41598-017-02509-2.
Descending connections from brainstem nuclei are known to exert powerful control of spinal nociception and pain behaviours in adult mammals. Here we present evidence that descending serotonergic fibres not only inhibit nociceptive activity, but also facilitate non-noxious tactile activity in the healthy adult rat spinal dorsal horn via activation of spinal 5-HT receptors (5-HTRs). We further show that this differential serotonergic control in the adult emerges from a non-modality selective system in young rats. Serotonergic fibres exert background 5-HTR mediated facilitation of both tactile and nociceptive spinal activity in the first three postnatal weeks. Thus, differential descending serotonergic control of spinal touch and pain processing emerges in late postnatal life to allow flexible and context-dependent brain control of somatosensation.
已知脑干核团的下行连接对成年哺乳动物的脊髓伤害感受和疼痛行为具有强大的控制作用。在这里，我们提供的证据表明，下行 5-羟色胺能纤维不仅抑制伤害性活动，而且通过激活脊髓 5-羟色胺受体（5-HTRs）促进健康成年大鼠脊髓背角的非伤害性触觉活动。我们进一步表明，这种成年大鼠中不同的 5-羟色胺能控制来自于幼年大鼠中一种非模态选择性系统。在出生后的前三周，5-羟色胺能纤维对触觉和伤害性脊髓活动施加背景介导的 5-HTR 促进作用。因此，脊髓触压和疼痛处理的下行 5-羟色胺能控制的差异在出生后晚期出现，以允许大脑对躯体感觉进行灵活和上下文相关的控制。
