大鼠慢性缩窄环术三叉神经痛模型的行为与组织学变化研究

Behaviour and histological changes in rat with trigeminal neuralgia model by chronic constriction injury

目的研究三叉神经慢性缩窄环术大鼠对机械刺激的行为与反应阂值和三叉神经的组织学改变的关系。方法在大鼠左侧三叉神经分支眶下神经（infraorbital nerve，ION）行缩窄环术（chronic constriction iniury，CCI），观察术后不同时段大鼠对机械刺激的反应阈值（疼痛阈值）及三叉神经组织学改变。结果术后2--8周，在ION支配区域内，大鼠出现痛觉超敏现象，与术前及对照组比较存在统计学差异（P〈0．01），ION—CCI区域神经纤维肿胀，髓鞘脱失，正常结构消失，术后12周左右疼痛阈值恢复至术前水平，神经纤维基本恢复正常。结论三叉神经慢性缩窄环术后大鼠对机械刺激的反应阅值降低且与其局部神经纤维脱髓鞘改变密切相关。

Objective To study the pain-related behaviour and histological changes after chronic constriction injury on trigeminal nerve in rat. Methods An unilateral chronic constriction injury （CCI） was produced by placing a loose chromic gut ligatures around the infraorbital nerve（ION）. The pain-related behaviour and the histological changes of ION were observed at different times before and after the operation respectively. Result A hyperalgesia reaction to mechanical stimulation in the territory of ligated ION was found from the 2nd to the 8th week after the operation. There was signif- icant difference （P 〈 0.01） in pain threshold compared with that of preoperation and controlled groups. The nerve fibers of the ION were obviously injured. The pain thresholds recovered to its orig- inal level and the injured nerve almost recovered to normal on 12th week after the operation. Conclusion The reactive threshold is degraded to mechanical stimulation in rats following chronic constriction injury of trigeminal nerve, which appears to be closely linked to the histological changes in the rat with ION.