Study On The Types Of Fluid Percussion Impact Traumatic Brain Injury Models In Mice Hippocampus

Objective Traumatic brain injury animal model is the basic platform for the study of brain injury mechanisms and treatment methods. Because mice’s gene sequence is relatively close with human’s gene sequence, and they are easyly coveraged、low cost, so mice are one of the most commonly used animals fo-r the production of traumatic brain injury small animal model. So far as now, people developed a number of ways to create traumatic brain injury models i-n mouse, in which fluid percussion impact(FPI) method is one of the most co-mmonly used methods. But there is no systematic study on how to establish different degrees of FPI hippocampus traumatic brain injury models in mouse. To establish a stable varying degrees of FPI hippocampus traumatic brain injur-y models in mouse, We used standard surgical techniques and fluid percussio-n instrument, and established a solid foundation for the future studies of traum atic brain injury.Methods180healthy adult male C57/BL6mice were randomly divided into th-e control group (n=30), the experimental groups:mild injury group (n=50)、m-oderate injury group (n=50) and heavy injury group (n=50). The experimental and control groups were under standa-rdized surgical procedure. Selected2mm rear of the anterior fontanelle point,2mm right of the sagittal suture as the ce -nter drill, grinded a bone hole of2mm diameter. The experimental groups ad-opted hydraulic combat to produce traumatic brain injury models. The control group mice underwent the same surgical procedure without being exposed to p-ercussion injury. The hydraulic combat pressures for mild injury、moderate inj-ury and heavy injury groups were0.6-0.8atm,1.6-1.8atm and2.6-2.8atm. The mNSS test, Morris water maze test, TTC staining, HE staining, and the small animal MRI examination were conducted at different times after TBI.Results We observed the mice after TBI, found that the more severely brain was damaged, the higher mortality of mice, lower behavior scores, more sever-ely brain edema and more obviously of changes in MRI images. The mice’s s-patial orientation and memory function was impaired after TBI. The mortality of each experimental group mice was significantly different after TBI(P<0.05). The mNSS scores were significantly higher in experimental group at1、2and3days after TBI compared with those of control group (P<0.05). The mNSS scores decreased gradually with the recovery of mouse. The escape latency an-d the percentage of target quadrant of mice in each group was significantly d-ifferent (P<0.05).Conclusion This FPI hippocampus traumatic brain injury model in mouse has some advantages, for example, the degree of injury is stable and reproducible, the individual random error is small. After repeated practice, we summed up standardized procedures to establish this model. Traumatic brain injury made by this model can be clearly classificated, shows that this model can stably produced varying degrees of TBI. This animal model provides an excellent animal experimental platform for the future study of traumatic brain injury.