云彩店邀请码|半壳|优胜
Neuropathic pain refers to pain that originates from pathology of the nervous system. Nerve compression,nerve injury、infection、diabetes、channelopathies and autoimmune disease are examples of diseases that may cause neuropathic pain. The development of both animal models and newer pharmacological strategies has led to an explosion of interest in the underlying mechanisms.The chronic constriction injury (CCI) model is more applied in the neuropathic pain research, which was established by the Bennett and his colleagues in 1988.It was reported that animal would represent hyperalgesia、paraesthesia and spontaneous pain after operation.The nerve fibers of injury region would produce lasting afferent spontaneous discharges which presented rich rhythm.Moreover, when the nerve fibers were injuried, the relationship of the neuron and target cell was disturbed, the transportation of the nutrient substance from neuron to target cell was disturbed synchronously,and induced nutrient supply discontinuity and metabolic disturbance.The nerve fibers of injury area would experience a complicated nerve degeneration and regeneration process. ?Those result indicated that animal behavior and the structure、function of the nerve fibers of injury region arose a series of abnormal change after injury.However, the CCI model has its intrinsic defects:On the one hand,operation has individual difference, especially the ligation strength was hard to unification.On the other hand, subsequent work indicated that an idiosyncratic immune-mediated response to the chromic suture played a major role in the development of the model after surgery.Further more, behavior representation after surgery 、spontaneous discharge types and characteristc 、morphological observation of the injury region have not been systematically studied.Therefore, it is very necessary that the later study should pay more attention to modify the CCI model and combine the animal behavior 、function and morphology of the nerve fibers,so as the result will be more close to the actual law of the nerve system. Based on the previous studies, this study adopted the modified CCI model, chose the collagen fibers of the rat tail instead of the chromic suture. Moreover, animal surgery and behavior text were operated by the same lab assistant.Our study mainly pay much attention to those aspects: The characteristic of the sensory and motor function in the CCI model after surgery; Types and chracteristic of spontaneous discharge in the injury region; Degeneration and regeneration of the never fibers in the injury region.The test mainly contain three parts: The first part is to test hyperalgesia of the rats after surgery by mechanical and thermal stimulation and to test the motor function by sciatic functional index.The second part is to choose the hyperalgesia rats and observe the types、characteristic and quantity of the spontaneous discharge in the injury region.Finally, choose the hyperalgesia rats to observe the order、swell、degeneration and regeneration of the nerve fibers in the injury region.The main results are as follows:1. The movement of the Sham group rats after surgery were in normal condition. However, the CCI group rats exhibited many of clinical signs of neuropathic pain, including the ipsilateral claw constriction and dyskinesia.2. Mechanical sensitivity and thermal sensitivity increased significantly in the experiment group compared with that in control group.Mechanical withdrawal threshold and thermal withdrawal latency did not reach the low-water mark on 14 day after operation.However, the motor function of CCI group gradually recovered to normal condition.3. Large numbers of spontaneous discharge were observed in the injury region.Simultaneously, there were three different Firing patterns were observed: Integer multiple bursting, Intermittent period spiking and Periodic spiking.However, Periodic spiking and Integer multiple bursting were the main firing patterns (78/80, 93.75%).4. Nerve fibers of injury region got swell and degeneration between 1 to 7 days after operation. Compared with the proxical nerve fibers, distal nerve fibers got swell and degeneration more quickly and seriously.On 14 day after surgery, exterior wound of the rats almost heal up to nomal condition, the swell nerve fibers in the injury region were alleviated and the order of the nerve fibers were improved as well, but the degeneration nerve fibers would also be observed in the injury region.Based on the previous studies, the new discoveries of this research are as follows: Mechanical sensitivity and thermal sensitivity increased significantly in the experiment group (CCI group) ,compared with that in control group (Sham group), but the motor function of CCI group gradually recovered to normal condition; Periodic spiking and Integer multiple bursting were the main firing patterns; Exterior wound of the rats almost healed up to nomal condition, but the degeneration nerve fibers would also be observed in the injury region on the 14 day after operation.This study test and vetify tha fact that animal will show the disorder of movement in behavoir text,the structure and function in injury region also show abnormal condition, it also indicates abnormal discharge and the hyperalgesia are very close to each other,different firing patterns may indicate different afferent information.Regeneration of the nerve fibers in the injury region after surgery may undergo a very complicated pathological and physiological process.
来源:半壳优胜鲸鱼幸运星转载请保留出处和链接!
本文链接:http://87cpy.com/246372.html
本站部分内容来源网络如有侵权请联系删除