Objective To observe the effect of electroacupuncture(EA) stimulation of auricular concha region(ACR) on behavior changes of depression rats.Methods A total of 80 male Wistar rats were randomized into depression model(model

n=6)

EA-ACR(n=12)

preventive EA-ACR(Pre-EA-ACR

n=11)and EA-ear-tip(n=12)groups.Depression model was established by chronic unpredictable mild stress for 21 days and isolated breeding.Open-field test and sucrose solution intake prefe-rence test were conducted to assess changes of the rats' behavior activities before modeling and on day 22

36 and 50 after star-ting model.For rats of the pre-EA-ACR group

EA(2 Hz

1 mA) was applied to the bilateral auricular concha area for 20 min

once daily for 14 days

beginning from the 8th day on after starting model preparation till the end of the modeling

and for rats of the EA-ACR and EA-ear-tip groups

EA was given to the bilateral ACR and ear-tips respectively

beginning after modeling

once daily for 14 days.Results In comparison with pre-modeling

the percentages of sucrose solution consumption in rats of the model group decreased gradually from day 22 to 50(P>0.05).Compared with the model group

the percentage of sucrose solution consumption in the EA-ACR group was increased significantly on day 50(P<0.05)

suggesting an inhibitory effect of EA on the reduction of sucrose intake preference at this time-point.No significant differences were found between the pre-EA-ACR and the model groups and between the EA-ear-tip and model groups as well as between the EA-ACR and model groups at most time-points(P>0.05).Open-field test showed that in comparison with pre-modeling in the same one group

the total scores

crossing and rearing scores on day 22 were decreased considerably in the model and EA-ear-tip groups(P<0.05

P<0.01)

rather than in the pre-EA-ACR and EA-ARC groups(P>0.05)

suggesting a suppressing effect of pre-EA-ACR and EA-ACR on depression behavior.Compared to day 22 in the same one group

the total scores

crossing and rearing scores on day 36 and 50 in the pre-EA-ACR and EA-ear-tip groups were decreased significantly(P<0.05

P<0.01).Conclusion EA of auricular concha region can restrain the development of depression behavioral status in depression rats

which is superior to that of EA of ear-tip.