大鼠背侧海马注射谷氨酸钠对脑干相关镇痛核团SOMmRNA表达的影响

Effects of expressing of SOM mRNA in related nuclei of brain stem after stimulating rat dorsal hippocampus

目的 :探讨刺激大鼠背侧海马对脑干某些神经核团生长抑素SOMmRNA表达的影响 ,分析海马在痛调制中的作用机制。方法 :健康成年Wister大鼠 40只 ,随机分为 4组。A组 :正常对照组 ,B组 :疼痛组 ,以大鼠右侧后肢足底皮下注射 4g/L多聚甲醛 2 0 0 μl,作为疼痛模型。C组 :化学刺激组 :向痛模型动物海马内注射 0 .5 μlL 谷氨酸钠。D组 :生理盐水 :向疼痛模型动物海马内注射 0 .5 μl生理盐水。均于 12h后处死 ,常规灌注冰冻切片 ,采用地高辛标记反义RNA探针原位杂交 ,及计算机图像分析术 ,检测中脑导水管周围灰质 (PAG) ,中缝大核 (NRM )和外侧网状核 (LRN)SOMmRNA阳性神经元细胞个数及光密度等均值。结果 :疼痛刺激后PAG、NRM、LRN内SOMmRNA表达较正常明显增高 (P <0 .0 5 ) ,化学刺激组 ,PAG、LRN内SOMmRNA表达较疼痛组进一步增强 ,而NRM内SOMmRNA表达较疼痛组无明显变化。结论 :海马兴奋 ,引起PAG、LRN内SOMmRNA表达增加 ,因此 。

Objective: To study the effects of the expressing of SOM mRNA in related nuclei of brain stem after stimulating of hippocampus of the rat and investigate the mechainsm of hippocampal analqesia.Methods: Fourty adult Wister rats were randomly divided into 4 groups:①normal group;②pain group:0.2 ml 4 g/L formalin was subcutaneously injected into right hindpaw of rat;③sodium glutamate group 0.5 μl sodium glutamate was microinjected into the right hippocampus;④normal saline group:same treatment as sodium glutamate but microinjected 0.5 μl physiological saline.After 12 hours all rats were executed and perfused.Sections were made for ISHH,then proceeded by computed image analyzer.The number and optic densities of SOM mRNA positive cells of PAG?NRM and LRN were measured.Results: After pain stimulation,the expression of SOM mRNA in PAG and NRM increased than normal level.In sodium glutamate group,SOM mRNA positive cells in PAG and LRN increased than pain group;But in the NRM,there was no change.Conclusion: The stimulating hippocampus could produce a increasing expression of SOM mRNA in PAG,LRN,NRM.So SOM may have relationship of analgesia with PAG?LRN.