The Comparison Of Electronic Lesion Of Pyramidal Tract And Internal Capsule Hemorrhage In Establishing Spastic Rats

Objective To compare the differences between electronic lesion of pyramidal tractand internal capsule hemorrhage in establishing spastic paralysis rat model，to get moststable，effective，simple and convenient method for spastic paralysis rat model，toprovide an ideal tool for research and clinical diagnosis and therapy.Methods80healthy，clean SD male rats weighing200-250g，provided by DalianMedical University experimental animal center，were randomly assigned into threegroups：electronic lesion group（28rats），internal capsule hemorrhage group（28rats）and control group（including12rats in the control group for electronic lesion and12ratsfor internal capsule hemorrhage）.All rats get training for adhensive-removal test3daysbefore operation，and they were enrolled into experiments only after they had the sameperformance in behavioral tests.Rat models were set up as following：rats in electroniclesion group received stereotacticly direct current stimuli in the left side of thepyramidal tract，while，their control group had no electronic stimuli；rats in internalcapsule hemorrhage group were injected autologous tail venous blood into the leftinternal capsule，and their control group had nothing injected.Every group were furtherdivided into4subgroups：post-operation7days，14days，21days，and28daysgroup.The following behavioral tests were recorded：modified Ashworth score，mNSS，Faden，adhensive-removal tests.Then，every the amplitude and latent of both sidegastrocnemius muscle H reflex for every rat were detected. The left aide quadricepsfemoris of each rat were put into liquid nitrogen and cut into frozen section.Quadricepsmyosin adenosine triphosphat（eATPase）immunohistochemical staining were performedto detect the amount of type I muscle fiber and type II muscle fiber.Results （1）After operation，rats in electronic lesion group walked around towardthe right side（contralateral of lesion side）.Their general conditions were bad，and were easily frightened.They had less food and their body weight decreased greatly afteroperation（about5%-6%，recovered gradually after post-operation14days）.Themortality was3.6%.The left hind limb were lame rats in internal capsule hemorrhagegroup，and their weight loss was about4%compared to that before operation（begun torecover after post-operation14days）.The mortality was7.1%.（2）The muscle tonewas increased greatly in electronic lesion group and internal capsule hemorrhage group；motor function，forelimb sensory of contralateral lesion side and balance function weredecreased significantly.The abnormalities of electronic lesion group in all behavioraltests persisted to postoperative28days.However，the increased muscle tone andcontralateral lesion side forelimb sensory dysfunction of internal capsule hemorrhagegroup persisted to postoperative14days.Besides， compared to internal capsulehemorrhage group，all behavioral tests of electronic lesion rats had significant difference（p＜0.01），and persisted to postoperative21days.（3）Compared to the contralateralleft side and the right side in control group，the gastrocnemius muscle H reflex inparalysed side（right side）in electronic lesion group：the latency were decreasedobviously（persisted to postoperative28days）（p＜0.01），and the amplitude wereincreased（persisted to postoperative21days）.Compared to the contralateral left sideand the right side，in control group，the gastrocnemius muscle H reflex of paralysis side（right side）in internal capsule hemorrhage group：the latency were decreasedobviously（persisted to postoperative7days），and the amplitude were increased（persisted to postoperative14days，p＜0.01）.However，compared to the right side ofinternal capsule hemorrhage group，the right side H reflex of electronic lesion group：latency were decreased significantly and the amplitude were increased obviously，andthese could be observed till postoperative28days and21days，respectively（p＜0.01）.（4） Type II muscle fiber was the mainly muscle fiber in quadriceps femoris of controlrats.And the percentage of type I muscle fiber was3.5%.The percentage of type Imuscle fiber in right quadriceps femoris in postoperative7days，14days，21dayselectronic lesion group rats were7.16%，5.42%，4.80%， respectively.And thepercentage of type I muscle fiber were enhanced significantly as compared to control group（p＜0.01）.The percentage of type I muscle fiber of right quadriceps femoris inpostoperative7days，14days internal capsule hemorrhage rats were5.07%and3.78%.And the percentage of type I muscle fiber were enhanced as compared to controlgroup（p＜0.05）.Compared to internal capsule hemorrhage rats，type I muscle fiber ofelectronic lesion rats were enhanced significantly，and persisted to postoperative21days（p＜0.01）.Conclusion As compare to internal capsule hemorrhage， electronic lesion ofpyramidal tract method has the following advantages in establishing spastic paralysis ratmodel：（1）easy and simple to handle，low mortality；（2）the muscle tone is increasedmore obviously（；3）Neurological deficits persist longer，and the damage is more serious；（4） The abnormalities in electrophysiology persist longer；（5）The amount of type Imuscle fiber increases more obviously.Therefore， compared to internal capsulehemorrhage，electronic lesion of pyramidal tract is an ideal stable method for spasticparalysis rat model establishment，which is more simple and convenient，havingincreased muscle tone.2...