美国哈佛医学院David D. Ginty研究小组发现介导来自远端结肠的生理和病理机械感觉的DRG传入神经。2023年8月3日，国际知名学术期刊《细胞》发表了这一成果。

研究人员报告了从基因上定义的具有不同形态和生理特性的结肠支配背根神经节（DRG）神经元亚群。四个支配结肠的DRG神经元群具有机械敏感性，对结肠扩张表现出不同的力阈值。使用Bmpr1b基因工具选择性标记的阈值最高神经元群对结肠高度膨胀的行为反应是必要且充分的，这种反应部分由机械感觉离子通道Piezo2介导。

在炎症性肠病模型中，这种Aδ-HTMR群体介导了对炎症引起的结肠膨胀的行为过度反应。因此，与皮肤DRG机械感受器群一样，结肠神经机械感受器也表现出独特的解剖和生理特性以及力阈值空间，而基因定义的结肠神经HTMR介导了结肠膨胀的病理生理反应，从而揭示了治疗干预的目标群。

据悉，支配远端结肠的DRG神经元的特性还没有得到很好的定义，这阻碍了人们对它们在正常生理和胃肠道（GI）疾病中作用的了解。

附：英文原文

Title: DRG afferents that mediate physiologic and pathologic mechanosensation from the distal colon

Author: Rachel L. Wolfson, Amira Abdelaziz, Genelle Rankin, Sarah Kushner, Lijun Qi, Ofer Mazor, Seungwon Choi, Nikhil Sharma, David D. Ginty

Issue&Volume: 2023/08/03

Abstract: The properties of dorsal root ganglia (DRG) neurons that innervate the distal colon are poorly defined, hindering our understanding of their roles in normal physiology and gastrointestinal (GI) disease. Here, we report genetically defined subsets of colon-innervating DRG neurons with diverse morphologic and physiologic properties. Four colon-innervating DRG neuron populations are mechanosensitive and exhibit distinct force thresholds to colon distension. The highest threshold population, selectively labeled using Bmpr1b genetic tools, is necessary and sufficient for behavioral responses to high colon distension, which is partly mediated by the mechanosensory ion channel Piezo2. This Aδ-HTMR population mediates behavioral over-reactivity to colon distension caused by inflammation in a model of inflammatory bowel disease. Thus, like cutaneous DRG mechanoreceptor populations, colon-innervating mechanoreceptors exhibit distinct anatomical and physiological properties and tile force threshold space, and genetically defined colon-innervating HTMRs mediate pathophysiological responses to colon distension, revealing a target population for therapeutic intervention.

DOI: 10.1016/j.cell.2023.07.007

Source: https://www.cell.com/cell/fulltext/S0092-8674(23)00740-7