针刺研究2023，Vol.48Issue(12)：1183-1192,10.DOI:10.13702/j.1000-0607.20221141
结肠炎模型小鼠内脏痛及穴位敏化的外周神经机制探讨
Peripheral neural mechanism of visceral pain and acupoint sensitization in 2,4,6-trinitrobenzene sulfonic acid-induced colitis model mice
摘要
Abstract
Objective To explore the neural mechanism of visceral pain and related somatic(acupoints)sen-sitization by using in vivo calcium imaging of dorsal root ganglia(DRG)neurons.Methods Eight BALB/c mice were randomly divided into control and model groups,with 4 mice in each group.The colitis model was induced by colorectal perfusion of 2,4,6-trinitrobenzene sulfonic acid(TNBS)once daily for 7 days.Mice of the control group received colorectal perfusion of normal saline once daily for 7 days.The location and area of the somatic neurogenic inflamma-tion(cutaneous exudation of Evans blue[EB])of the 2 groups of mice were observed after intravenous injection of EB.For pain behavioral tests,sixteen C57BL/6J mice were randomly divided into control and model groups,with 8 mice in each group,and a Von Frey filament was used to stimulate the referred somatic reactive regions in colitis mice,and the number of avoidance and paw withdraw reaction within 10 tests was recorded.For in vivo DRG calcium imaging tests,24 Pirt-GCaMP6s transgenic mice were randomly and equally divided into control group and colitis model group.The re-sponses of the neurons in L6 or L4 DRG to colorectal distension(CRD),lower back brushing,or mechanical stimula-tion at the hindpaw were observed using confocal fluorescence microscope.Results Compared with the control group,the area of EB exudation spot in the hindpaw and lower back regions was increased in the colitis model group(P<0.05),and the avoidance or paw withdraw numbers induced by Von Frey stimulation at the lower back and hindpaw were increased(P<0.01,P<0.05),indicating that colitis induced regional skin(acupoints)sensitization in the lower back and hindpaw regions.Compared with the control group,the percentage of L6 DRG neurons activated by 60 mm Hg CRD in the colitis model mice were apparently increased(P<0.01),the activated neurons mainly involved the medium-sized DRG neurons(P<0.01).In Pirt-GCaMP6s transgenic mice,following brushing the skin of the receptive field(lower back)of L6 DRG neurons,the fluorescence intensity of the brushing-activated DRG neurons and small,medium and large-sized neurons were significantly higher in the colitis model group than those in the control group(P<0.001,P<0.01,P<0.05).After brushing and clamping the skin of the right hindpaw(receptive field of L4 DRG neurons),the per-centages of the activated L4 DRG neurons were obviously higher in the colitis model group than those in the control group(P<0.01,P<0.05),while there were no significant changes in the proportion of small,medium and large-sized neurons between the control and colitis model groups.Conclusion Colitis may lead to body surface sensitization at the same and adjacent neuro-segments as well as to an increase of the number and activity of the responsive lumbar DRG neurons,among which the L6 DRG neurons at the same neuro-segment as the rectum colon showed an increase in the number of responders and intensity of calcium fluorescence signal while L4 DRG neurons at the level adjacent to the rectum colon showed an increase in the number of responders,suggesting that there may be different mechanisms of peripheral neural sensitization.关键词
穴位敏化/结肠炎/在体钙成像/背根节/神经元Key words
Acupoint sensitization/Colitis/In vivo calcium imaging/Dorsal root ganglion/Neuron分类
医药卫生引用本文复制引用
高昕妍,张楠,刘坤,奚晗清,刘允,何勋,韩数,朱兵..结肠炎模型小鼠内脏痛及穴位敏化的外周神经机制探讨[J].针刺研究,2023,48(12):1183-1192,10.基金项目
国家自然科学基金面上项目(No.81973963、81973967) （No.81973963、81973967）
