Abstract: Objective To establish a high morbidity and low mortality of animal model for facial paralysis in rats, which is easy to operate. Methods Fifty SD rats with half male and female were randomly divided into five groups, each group with 10. The facial nerve trunk of rats were clipped with mosquito forceps closing three tooth for 6 min, 8 min, 10 min, 12 min and 14 min. The compound muscle action potential (CMAP) amplitude of facial nerve trunk was measured by biological function experiment system, and the general behavior indices of all the rats were observed next day after injury. Results The CMAP amplitude of rats after facial nerve trunk clipped for 6 min and 8 min respectively were the same as none clipped rats, but it decreased obviously and tended to zero after clipped for 10 min, 12 min and 14 min. In addition, ethology score results showed that the models of 6 min, 8 min rats performed incomplete paralysis symptoms, the models of 10 min,12 min,14 min rats were facial paralysis completely and the models of 14 min and 12 min rats had no obvious difference compared with the model of 10 min. Conclusion The decreased CMAP amplitude of facial nerve trunk and ethology score results showed that clipping the facial nerve trunk with the mosquito forceps closing three tooth for 10 min was the best way to establish rats model of facial paralysis.

Key words: Rat, Facial paralysis model, Facial nerve, Compound muscle action potential (CMAP)