改良CCI大鼠痛行为学检测与损伤区自发放电活动再观察

Pain Behaviour and Ectopic Spontaneous Discharge in Modified Chronic Constriction Injury Rats

目的:应用改良CCI模型研究外周神经损伤后痛觉过敏和自发放电各自特征及相互关系。方法:雄性SD大鼠,随机分为CCI组和Sham组,分别于术前1天和术后1、4、7、9、11、14天测定机械刺激缩足反射阈值和热缩腿反射潜伏期,同时选取术侧机械刺激缩腿反射阈值低于4g或者术侧和健侧热缩腿反射潜伏期差异大于2s的CCI模型大鼠观察术后4-14天损伤区自发放电活动。结果:神经纤维损伤后,机械痛敏和热痛敏随时间表现为逐渐增强,同时在损伤区观察到三类放电模式:整数倍放电﹑阵发放电和周期放电。结论:术后大鼠机械痛阈和热痛阈逐渐降低,机械痛敏的产生和损伤区自发放电活动关系密切,不同的放电模式可能代表不同的传入信息。

To investigate characteristic and the relationship of the hyperalgesia and spontaneous discharges in modi-fied CCI rat.Methods： Male adult SD rats were randomly divided into experiment group（CCI） and control group（Sham）.The mechanical withdrawal threshold（MWT） and thermal withdrawal latency（TWL）were detected before operation and on 1d,4d,7d,9d,11d,14d after op-eration.The rats with MWT less than 4 g or with a TWL the difference of which was higher than 2 s between ipsilateral and contralateral hind paws were selected and used in the subsequent electrophysiological studies.Results： Mechanical sensitivity and thermal sensitivity increased significantly in the experiment group compared with that in control group.There were three different Firing patterns： Integer multiple bursting,Intermittent period spiking and Periodic spiking.Conclusion： Threshold of mechanical and thermal pain decreased gradually after surgery and the abnormal discharge and the mechanical sensitivity were very close to each other.Different firing patterns may indicate different afferent information.