摘要
目的:探讨刺激大鼠背侧海马对脑干部分神经核团生长抑素(SOM)mRNA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wistar大鼠40只,随机分为4组。A组:正常对照组,不给动物任何处理;B组:疼痛刺激组,大鼠右侧后肢足底皮下注射4 g/L多聚甲醛200μl,作为疼痛模型。C组:电刺激组,将疼痛模型动物经腹腔注射20 mg/L戊巴比妥钠麻醉后,借助于脑立体定位仪,待大鼠清醒后,按Paxinos和watson大鼠脑图谱,用同心圆电极于大鼠右背侧海马给予方波电刺激,时间为2 min。D组:电刺激对照组,操作同电刺激组但不通电,时间为2 min。 4组动物均于12 h后处死,经主动脉灌注,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技术,分别检测中脑导水管周围灰质(PAG),中缝大核(NRM)和外侧网状核(LRN)SOM mRNA阳性神经元细胞数及光密度值。结果:疼痛刺激后,PAG、NRM、LRN内SOM mRNA表达较正常明显增高(P<0.01),电刺激组PAG、LRN的SOM mRNA表达较疼痛刺激组进一步增加,而NRM内SOM mRNA较疼痛刺激组增加不明显。结论:海马兴奋可引起PAG、LRN神经元SOM mRNA表达增加,因此,SOM可能与脑干PAG和LRN参与镇痛有关。
Aim: To study the expression of SOM mRNA in PAG, NRM, and LRN in brain stem after electric stimulating hippocampus and investigate the mechanism of hippocampal analgesia. Methods: Fourty adult Wistar rats were randomly allocated into 4 groups. Normal Group:normal rats without any treatment. Pain Group:rats with 200 μl 4 g/L formalin subcutaneously injected into right hindpaw. Electric Stimulation Group: locating the dorsal hippocampus of the rats in the sterotaxic coordinates after 200 μl formalin was injected about 15 min,and inserting an electrode then electric stimuli had been given for about 2 min. Electrode-Left Group:same treatment as Electric Stimulation Group but without electric current. After 12 hours all rats were executed and perfused. Sections were made for in situ hybridization histochemistry (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,LRN and NRM increased compared to normal level. After electric stimulation SOM mRNA positive cells in PAG and LRN increased compared to Pain Group, but in the NRM, there was no significant change. Conclusion; The stimulation of hippocampus could produce an increasing expression of SOM mRNA in PAG and LRN, SOM may be related to the analgesia with PAG and LRN.
出处
《郑州大学学报（医学版）》
CAS
北大核心
2003年第1期40-43,共4页
Journal of Zhengzhou University(Medical Sciences)
基金
河南省自然科学基金资助项目 994024300
关键词
电刺激
海马
生长抑素
镇痛
原位交
hippocampus
somatostatin
analgesia
in situ hybridization
