Role Of Synaptophysin And Mossy Fiber In The Genesis Of The Post-traumatic Epilepsy

Object:1. Investigate the changes of the electroencephalogram and ethology in the rats with fluid percussion brain injury to approach their research value in post-traumatic epilepsy.2. Investigate the changes of brain synaptophysin expressionand mossy fiber sprouting of post- traumatic epileptic and no epileptic rats after fluild percussion brain injury,and explore the pathogenesy of post-traumatic epilepsy.Methods:1. The establishment of post-traumatic epilepsy with lateral fluid percussion brain injury: We established the rat models of post-traumatic epilepsy according to the method proposed by D'Ambrosio.2. Grouping: Rats were randomly divided into:①sham group: Given the same operation as the experimental group, but no percussion. This group was named as group A (n = 8);②Experimental group (this group was named as group B )(n = 50): Rats were injured with fluid percussion injury. We recorded survival rats'electroencephalogram and ethology changes for 3 months. epileptic rats were named as epileptic group (group C), no epileptic rats were named as no epileptic group (group D);③Self sham group: It was also divided into 3 groups, they were named as group E(right of A),group F(right of C) and group G(right of D), We took brain tissue from injured area and its corresponding opposite side parts of the cerebral hemisphere for synaptophysin immunohistochemistry and mossy fiber Timm staining.3. Samples taking and detecting: Rats were anesthetized by abdominal cavity, poured into with isotonic Na chloride(4℃,150ml), PBS(0.01mol / L,pH7.4,4℃,200ml) of 4% paraformaldehyde, PBS(0.01mol/L,pH7.4,4℃,200ml) of 0.4% Sodium Sulfide in order through left ventricle-aortic cannula. We took out of brain 2 hours late, fixed it with 4% paraformaldehyde(PH 7.0,4℃) for 24 hours, cut it by coronal plane along posterior border of chiasm opticum. The post-part was put into 30% cane sugar(stay overnight, sink bottom), for frozen section ,Timm stainning; The ante-part was fixed by 4% paraformaldehyde continually, for paraffin sections, synaptophysin immunohistochemistry stainning.Results:There are 11 rats that appeared epilepsy in the survival 31 rats(mortality 38.0% and incidence 35.5%). The manifestation of epileptic seizure were facial spasm, nod motion, limbs convulsion and turnover upspring. The highest epileptic incidence rate appeared in the 1~2 months after lateral fluid percussion brain injury. There were obvious epileptic discharges on the electroencephalogram of epileptic rats and the higher of wave amplitude and quicker frequency on the lead of 1-5 on the electroencephalogram of some no epileptic rats. Synaptophysin expression increased in the injury cerebral cortex of in epileptic rats(P <0.05), mossy fiber sprouting increased in the stratum of hippocampal CA3 region of injured side in epileptic rats (P <0.05).Conclusion:Post-traumatic epilepsy after lateral fluid percussion brain injury in the rat is similar with clinical post -traumatic epilepsy. It has more research value than the other post-traumatic epileptic animal model. Increased expression of synaptophysin and mossy fiber sprouting are concerned with the development of post-traumatic epilepsy.