| Objective: According to the present study of spastic cerebral palsy(SCP)animal model and the etiology of SCP, we establish the SD(Sprague Dawley)rat model of SCP by the ways of electric lesion and absolute alcoholdestruction to the pyramidal tract. Then based on the study of the ethology ofthe two models, we further analyze the pathological changes of each model,and investigate which model can largest simulate the ethological andpathological changes of SCP. We look forward to finally find a best way toestablish a steady SCP animal model.Methods：24clean adult SD rats, female or male, weight of about250grams, provided by the experimental animal center of Hebei MedicalUniversity, in the barrier environment provided by the experimental animalcenter of the Third Affiliated Hospital of Hebei Medical University, weredivide into3groups (each group contains8rats) by the random number tablemethod: Group A is electric lesion group, Group B is absolute alcoholdestruction group and Group C is control group. After weighing, the rats wereanesthetized by intraperitoneal injecting10%hydration chlorine aldehyde byper kilogram of body weight4-5ml. After anesthesia, the rats were fixed onthe brain solid positioner, cropped the hair, disinfected, cut the skin step bystep along the cranial roof midline incision about3cm, exposed the anteriorfontanelle and sagittalis suture, drilled in the cranial top at the position of theanterior fontanelle back10mm and the sagittalis suture left0.8mm(accordingto The Rat Brain in Stereotaxic Coordinates) with0.7mm diameter dental drill.①G roup A: The rats were inserted9.7mm vertically by0.6mm diameterpositive pole needle electrode, inserted by negative pole needle electrode at the tail, injured by electric current2.5mA for6×5s, twice (with30s interval),then pulled out the pole slowly, stopped the bleeding thoroughly, sealed thehole by bone wax immediately, rinsed the wound by0.9%physiological saline,sewed up the incision, breed alone.②Group B: The rats were inserted9.7mmvertically by25μl microinjector, slowly injected15μl absolute alcohol, thenpulled out the microinjector slowly, stopped the bleeding thoroughly, sealedthe hole by bone wax immediately, rinsed the wound by0.9%physiologicalsaline, sewed up the incision, breed alone.③Group C: The rats were inserted9.7mm vertically by25μl microinjector, then pulled out the microinjectorslowly, stopped the bleeding thoroughly, sealed the hole by bone waximmediately, rinsed the wound by0.9%physiological saline, sewed up theincision, breed alone. After the operation, we observe and compare the rat’ssymptoms and signs in every groups carefully.④72hours after theoperation(the rats’ symptoms become stable), the rats which were selectedrandomly from every group(2rats in each group) were anesthetized by abovemethod, taken out the whole brain carefully. Then all the brain tissues afterHE stain were observed by light microscope and taken for pathologicalanalysis.⑤The rest of the rats in every group were bred normally and keep aclose eye on their changes of temperament and ethology every day.Results: After operation, the rats of three groups all appear listlessness,slow response, no limbs active activities and diet activities.①The rats inGroup C are all survived.12h after the operation, they begin to graduallyrevive, increase sensitive reaction, limb and diet activity. The rats with slightpoor muscular tension have no spasticity.24h after the operation, the mind,response, activity, diet and sup of the rats are gradually normal. The rats withslight poor muscular tension have no spasticity.48h after the operation, theyare basic normal and with normal muscular tension have no spasticity.72hafter the operation, they are perfectly normal and with normal musculartension have no spasticity. Then feeding for6-8weeks, the rats still have noabnormal.②The survival rate of Group A is62.5%, the three rats die inpostoperative24h.24h after the operation, the survived ones begin to gradually revive, increase sensitive reaction, limb and diet activity, but theyare weaker than Group C. Meanwhile, they present the right limbs bucklingspasticity and movement in a clockwise circle of20cm diameter.36h-48hafter the operation, they are gradually close to normal but weaker than GroupC, and the symptoms of the right limbs buckling spasticity are like above.72hafter the operation, they are basic normal but weaker than Group C, and thesymptoms of the right limbs buckling spasticity are steady, last for about2-3weeks. Then the symptoms gradually decrease, and completely disappear after6-8weeks.③The survival rate of Group B is75%, the two rats die inpostoperative24h.24h after the operation, the survived ones begin togradually revive, increase sensitive reaction, limb and diet activity, but theyare weaker than Group C and Group A. Meanwhile, they present the rightlimbs buckling spasticity obviously, the tension of the flexor muscle arestronger than the left side, and movement in a clockwise circle of50cmdiameter.48h-72h after the operation, they are gradually close to normal butweaker than Group C and Group A, and the symptoms of the right limbsbuckling spasticity are steady.1week after the operation, they are basic normalbut weaker than Group C and Group A, and the symptoms of the right limbsbuckling spasticity are steady, last for about6-8weeks with no decrease. Inconclusion, the rats in Group B have more typical symptoms and signs of SCP.④Pathology results: The brains of rats in Group C have no obviouspathological histology change. The nerve cells at the pyramidal tract of theexperimental side brain in Group A are disorder arranged and swelling. Theparts of them are the degeneration necrosis cells. At this area, we can observerthat the normal tissue structures are damaged and a bit of small cysts. Thenerve cells at the pyramidal tract of the experimental side brain in Group B arewidely disorder arranged and obviously swelling. Most of them are thedegeneration necrosis cells. At this area, we can observer that the normaltissue structures are seriously damaged and a lot of cysts.Conclusions: The SD rat models of SCP established by the way ofabsolute alcohol destruction to the pyramidal tract have typical symptoms and signs of SCP, high stability and repeatability, and simple production process.The pathological and histological results indicate that the pathologicalhistology foundation changes of the SCP model spasticity are degenerationnecrosis of the brain pyramidal tract nerve cells. The SD rat models of SCPestablished by the way of absolute alcohol destruction to the pyramidal tractcan be widely used in the basal and clinical research of the SCP. |
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