Objective: To observe the effect of electroacupuncture(EA) on the expression of brain derived neurotrophic factor(BDNF) mRNA in nucleus of facial nerve of rabbits with facial nerve injury so as to reveal the mechanism of acupuncture in improving facial nerve injury.Methods: One hundred and twenty rabbits(Japanese big-earwhite) were randomly divided into control(sham-operation)

model

medication

hand-acupuncture and EA groups

with 24 cases in each group which was further divided into(7 d)

(14 d)

(21 d) and(28 d) phases.Facial nerve injury model was established by cramping the facial nerve(0.5 cm) to the stylomastoid foramen with a pair of forceps."Yifeng"(TE 17)

"Quanliao"(SI 18)

"Dicang"(ST 4)

"Jiache"(ST 6)

etc were punctured with filiform needles and stimulated with hand manipulation in hand acupuncture group

and stimulated electrically with the stimulation parameters being 1-(100 Hz) in frequency

(2 V) in strength and duration of(30 min).In medication group

muscular injection of the mixture solution of Vitamin B_1((10 mg))

B_(12)((50 μg)) and dexamethasone(DXM

(2 mg/d) in the first 7 days

(1 mg/d) later) was performed once daily.The treatment was given 1 week

2 weeks

3 weeks and 4 weeks respectively in different subgroups of every group.BDNF mRNA expression of the nucleus of facial nerve was detected by using in situ hybridization(ISH) technique.Results: Compared with control group

the number of BDNF mRNA expression-positive neurons in(7 d)

(14 d)

(21 d) and(28 d) phases of model group increased significantly(P<0.05)

while in comparison with model group

the number of BDNF mRNA expression-positive neurons in the 4 phases of medication

hand-acupuncture and EA groups increased further and pronouncedly(P<0.01)

and the effect of EA group was superior to those of medication and hand-acupuncture groups(P<0.01).Self-comparison indicated that compared with phase(7 d)

the number of BDNF mRNA expression-positive neurons in phase(28 d) of each treatment group was markedly more(P<0.01).No significant differences were found between medication and handacupuncture groups in the number of BDNF mRNA expression-positive neurons in the 4 phases(P>0.05).Results of hematoxylin-eosin(HE) staining showed a more significant improvement of neuronal degeneration in the nucleus of facial nerve in EA group.Conclusion: EA can promote the recovery of the injured facial nerve and upregulate BDNF mRNA expression in the nucleus of facial nerve in rabbits with facial nerve injury.