Objective To observe the effect of acupuncture on c-jun N-terminal Kinase(JNK)signaling in the hippocampus in rats with forced-swimming stress

so as to reveal its underlying mechanism in relieving depression-like motor response.Methods Forty-eight Sprague-Dawley rats were randomly divided into 8groups as control

control+JNK inhibitor(SP600125)

model

model+SP 600125

acupuncture

acupuncture+SP 600125

Fluoxetine(an anti-depressant)

and Fluoxetine+SP 600125(n=6in each group).The depression-like behavior(immobility)model was established by forcing the rat to swim in aglass-cylinder and solitary raise.Acupuncture stimulation was applied to"Baihui"(GV 20)and "Yintang"(GV 29)for 20 min before forced swimming and once again 24 hlater.The rats of the Fluoxetine and Fluoxetine+SP 600125 groups were treated by intragastric administration of fluoxetine 10mL(1.8mg)/kg before forced swimming and once again 24 hthereafter.The rats of the model+ SP 600125 and acupuncture+SP 600125 groups were treated by intraperitoneal injection of SP 600125(10mg/kg)90min before forced swimming and 30 min before acupuncture intervention

respectively.The immobility duration of rats in the water glass-cylinder was used to assess their depression-like behavior response.The expression levels of protein kinase kinase 4(MKK 4)

MKK 7

JNK

and phosphorylated JNK(p-JNK)in the hippocampus were detected by Western blot.Results Compared to the control group

the duration of immobility

and the expression levels of hippocampal MKK 4

MKK 7

and p-JNK proteins were significantly increased in the model group(P<0.01).While in comparison with the model group

the duration of immobility in the model+SP 600125

acupuncture

acupuncture+SP 600125

Fluoxetine and Fluoxetine+SP 600125 groups

the expression levels of hippocampal MKK 4and MKK 7proteins in the Fluoxetine+SP 600125 group

and those of p-JNK protein in the acupuncture

acupuncture+SP 600125

model+SP 600125

Fluoxetine and Fluoxetine+SP 600125 groups were considerably decreased(P<0.05

P<0.01).No significant differences were found between the control and control+SP 600125 groups and among the model+SP 600125

acupuncture

acupuncture+SP 600125

Fluoxetine and Fluoxetine+SP 600125 groups in the duration of immobility(P>0.05)

and in the expression level of p-JNK protein(P>0.05).No significant changes were found in the expression levels of JNK among the 8groups(P>0.05).Conclusion Acupuncture stimulation of GV 20 and GV 29 is effective in relieving depression-like motor response in forced-swimming stress rats

which may be closely associated with its effects in down-regulating the expression of hippocampal p-JNK protein.