Objective In order to study the difference of depression-like behaviours among three widelyused stress models in rats.Methods The new-born Spragne-Dawley rats were randomly divided into maternal deprivation(MD) group(n=27),chronic mild stress(CMS) group (n=29),dual stress(DS) group ( n=31 ) and control (C) group ( n =30) on postnatal day 1.MD rats only received maternal deprivation.CMS rats only received chronic mild stress when 10 weeks old.DS rats received both maternal deprivation and chronic mild stress.Control rats received no experimental handling.Behavior tests including forced swimming test and sucrose consumption which were carried out to evaluate rats' depression-like behaviors in the thirteenth weeks.The extend time of floating and sucrose preference ratio should be recorded in the forced swimming test and sucrose consumption test respectively to reflect the behavior of helplessness and anhedonia of rats.Results In the forced swimming test,the extend floating time of MD group( 119.30 ± 65.56) s,CMS group ( 145.00 ± 80.24) s and DS group ( 170.03 ±61.75 )s were longer than the control group(81.14 ± 52.40)s (F =11.53,P ＜ 0.01 ).In the sucrose consumption test,the MD group(0.32 ± 0.22) had a low sucrose consumption.The comparison of the MD group and CMS group (0.43 ± 0.28 ) to the control group (0.54 ± 0.28 ) had significant differences (F =4.33,P ＜ 0.01 ).In these four groups,no sexual difference was found in the forced swimming test and sucrose consumption test ( all P ＞ 0.05 ).Conclusion The results suggest that MD,CMS and DS may induce some kind of depression-like behaviors in rodents such as anhedonia or the behavior of helplessness and the depression-like behaviors induced by different stresses are similar in male and female individuals.

Malignant biliary obstruction is often in an advanced stage at the time of diagnosis, and palliative relief of obstruction has become the main treatment option. Biliary stent implantation is currently the most widely used treatment for the relief of biliary obstruction, but stent reobstruction has become a common problem in clinical practice. Endoscopic retrograde cholangiopancreatography (ERCP) combined with intraductal radiofrequency ablation can solve the problem of direct obstruction in malignant biliary obstruction and improve stent patency rate, survival time, and survival rate, with few complications and a low surgery-related mortality rate, and therefore, it can be used as a safe and feasible palliative treatment method for malignant biliary obstruction.