Abstract:

Objective  To evaluate dynamic expression changes of neurotrophin-4 (NT-4）in the rat facial nerve, vibrissae muscle and facial nucleus in response to facial nerve injury.  Methods    A rat model of facial nerve injury was established. Subsequently, all facial nerves, the vibrissae muscle and pons were taken out on days 1, 3, 7, 14, and 21 after injury. Expression of NT-4 mRNA was detected by RT-PCR. Expression of NT-4 at the protein level was simultaneously determined by Western blot and immunohistochemisty. Results  Expression of NT-4 was detected in the facial nerve, vibrissae muscle and facial nucleus. Expression of NT-4 was elevated and reached the peak at 14th day in the facial nerve and facial nucleus, whereas reduced in the muscle.  Conclusions   Expression of NT-4 was increased in the facial nerve and nucleus and decreased in the vibrissae muscle after facial nerve injury. These indicate that expression of NT-4 in the nerve tissue could be closely related to the injury in the facial nerve.

Key words: Facial nerve; Injury; Neurotrophic factor Ⅳ; Models, animal; Rats, Wistar