Objective To investigate the effect of acupuncture intervention on the depression behavior and expression of extracellular signal-regulated protein kinases(ERK 1/2)

p-ERK 1/2 and brain-derived neurotrophic factor(BDNF)in the prefrontal cortex of chronic unpredictable mild stress(CUMS)induced depression rats

so as to explore its antidepressant mechanism.Methods Sixty-four male SD rats were randomly divided into control

model

acupuncture

Fluoxetine

model+ Dimethyl sulfoxide(DMSO)

model+ PD 98059(an ERK pathway inhibitor)

acupuncture+ PD 98059 and Fluoxetine+ PD 98059 groups(n=8 rats in each).The CUMS depression model was established by using chronic mild and unpredictable stress methods for 21 days.Manual acupuncture stimulation was applied to"Baihui"(GV 20)and"Yintang"(GV 29)for 10 min before modeling

once daily for 21 days.Fluoxetine hydrochloride suspension(1.8 mg·kg

(-1)

·d(-1)·d

(-1)

)was given to rats of the Fluoxetine group and Fluoxetine+ PD 98059 group by gavage 30 min before CUMS.PD 98059(dissolved in DMSO

10 μL)was administered to rats of model+ PD 98059 group

acupuncture+ PD 98059 and Fluoxetine+ PD 98059 group

and DMSO(10μL)to rats of model+DMSO group by intracerebroventricular injection 1 hbefore CUMS.Sucrose consumption test was carried out to evaluate the depressive behavior.Western blot was performed to detect the expression of ERK 1/2

p-ERK 1/2 and BDNF of prefrontal cortex.Results Compared with the control group

the sucrose consumption and the expression levels of p-ERK 1/2 and BDNF protein in the prefrontal cortex were significantly reduced in the model and model+DMSO group(P

<

0.01).After the intervention

modeling induced decrease of the sucrose consumption

and p-ERK 1/2 and BDNF expression was significantly up-regulated in both acupuncture and Fluoxetine groups(P

<

0.01

P

<

0.05)

but not in the model+PD 98059

Fluoxetine+PD 98059 and acupuncture+PD 98059 groups(P

>

0.05).No significant differences were found among the model+PD 98059

Fluoxetine+PD 98059 and acupuncture+PD 98059 groups in the sucrose consumption

and ERK 1/2

p-ERK 1/2 and BDNF expression levels(P

>

0.05)

and in the expression levels of ERK 1/2 protein among the 8 groups(P

>

0.05).Conclusion Acupuncture intervention has an anti-depressive role in CUMS induced depression rats

which may be related to its effects in up-regulating the expression of p-ERK 1/2 and BDNF in the prefrontal cortex tissue.