Kawasaki Motohiro, Al-Chaer Elie D
Department of Internal Medicine, University of Texas Medical Branch, Galveston 77555-0632, USA.
Neuroreport. 2003 May 23;14(7):985-9. doi: 10.1097/01.wnr.0000070825.57864.db.
The purpose of this study was to examine the effect of cutaneous inflammation on the responses of viscerosomatic convergent dorsal horn neurons to graded colorectal distension (CRD) and cutaneous mechanical stimulation. Responses of single viscerosomatic neurons in the lumbar dorsal horn of the rat spinal cord to CRD and to cutaneous stimuli were recorded before and 50 min after cutaneous inflammation induced by intradermal injection of capsaicin in the receptive field (RF) or in the ipsilateral and contralateral forepaw. Capsaicin injection in the RF induced an increase in the spontaneous activity of dorsal horn neurons, an expansion in the size of their RF and facilitated their responses to cutaneous stimuli. An injection placed in the center of the RF attenuated the responses to noxious CRD. Capsaicin injection in the forepaw caused a significant decrease in the responses to CRD but not to cutaneous stimuli. These results indicate that the inhibitory effects, evoked by cutaneous inflammation, can modulate the responses of dorsal horn neurons to CRD, independent of its effect on the responses to cutaneous mechanical stimuli.
本研究的目的是探讨皮肤炎症对内脏-躯体汇聚性背角神经元对不同程度结直肠扩张（CRD）和皮肤机械刺激反应的影响。在大鼠脊髓腰段背角，记录单个内脏-躯体神经元在皮内注射辣椒素于感受野（RF）或同侧及对侧前爪诱导皮肤炎症前及50分钟后的CRD及皮肤刺激反应。在RF内注射辣椒素可使背角神经元的自发活动增加，其RF大小扩大，并促进其对皮肤刺激的反应。注射于RF中心可减弱对有害CRD的反应。在前爪注射辣椒素可使对CRD的反应显著降低，但对皮肤刺激的反应无影响。这些结果表明，皮肤炎症诱发的抑制作用可调节背角神经元对CRD的反应，而与对皮肤机械刺激反应的影响无关。
