Descending pain modulation shaping spinal signalling of colorectal nociception

Signalling of colorectal pain is regulated by descending pain mechanisms in the spinal cord. This study aimed to establish if the influence of descending pain modulation of colorectal pain signalling differs between spinal cord regions known to receive input from colorectal sensory fibres- the thoracolumbar (TL) and lumbosacral (LS) spinal cord. This was assessed by using immunolabelling for serotonin and tyrosine hydroxylase to identify descending input into the TL and LS spinal cord and their association with neurons activated by colorectal distension. This was followed by applying pharmacological mediators of descending transmission into either TL and LS spinal cord regions and measuring their affects on visceromotor responses evoked by in vivo colorectal distension. Then the expression of receptors mediating descending transmission was assessed and compared between TL and LS spinal cord full thickness and within dorsal horn regions isolated by laser microdissection. The resulting data is summarised in the attached PDF.

结直肠痛信号传导受脊髓下行痛觉调控机制的调节。本研究旨在明确：结直肠痛信号传导的下行痛觉调控效应，在已知接收结直肠感觉纤维输入的脊髓区域——胸腰段（thoracolumbar, TL）与腰骶段（lumbosacral, LS）脊髓之间是否存在差异。研究通过对5-羟色胺（serotonin）与酪氨酸羟化酶（tyrosine hydroxylase）开展免疫标记，以识别TL与LS脊髓的下行传入通路，并分析其与结直肠扩张激活神经元的关联。随后，研究人员向TL或LS脊髓区域施加下行传导的药理学介质，并检测其对体内结直肠扩张诱发的内脏运动反应的影响。继而，研究人员对介导下行传导的受体表达水平进行检测，并对比TL与LS脊髓全层组织，以及经激光显微切割分离的背角区域内的受体表达差异。本研究所得数据已汇总于附件PDF文件中。