In vivo study of effect of tianeptine on hippocampal volume of chronic stressed rats

Abstract

Objective To observe the change of the hippocampal volume of rats induced by chronic stress and effects of tianeptine on it. Methods 24 rats were randomly allocated into control(n=6), 4 week-stress(n=6), 4 week-stress with saline(n=6)and 4 week-stress with tianeptine(n=6)groups. Forced Swimming Test was used to set up stress animal model. the stressful responses were assessed by behaviour and serum corticosterone level. and hippocampal volume was measured in vivo by MRI. Results The serum corticosterone level of all the stressed groups(728. 67±77. 67, 765. 37±250. 87, 863. 49±282. 31)are significantly higher than that of control group(191. 60 ±116. 41), P＜0. 01. In absolutely left and right hippocampal volume, 4-week stress group(59. 45±5. 05, 61. 66±5. 32)and 4-week stress with saline group(61. 01±6. 06, 61. 43±3. 12)have smaller hippocampal volumes compared with control group(all P＜0. 01);4-week stress group with tianeptine has much bigger bilateral hippocampal volume than the 4-week stress group and 4-week stress with saline group(all P＜0. 01), but there is no significant difference between 4-week stress group with tianeptine and control group. The comparison of adjusted bilateral hippocampal volume is consistent with the absolute hippocampal volume. In addition, there is a positive correlation between the amount of acrossing and hippocampal volume, the coefficient correlations range from 0. 0557～0. 0598(P＜0. 05). Conclusion It was indicated that tianeptine could reverse the reduction of hippocampal volume caused by chronic stress. Key words: Stress; Corticosterone; Hippocampal volume; Tianeotine; In vivo