Effects of sleep deprivation on depressive behaviors and hippocampus bcl-xl in rats treated with chronic stresses

Abstract

Objective To explore the changes of Bcl-xl levels and activities in hippocampus resulting from sleep deprivation, and then to reveal the mechanism for rapid antidepressant aroused by sleep deprivation.Methods 40 SD rats were randomly divided into normal control group, chrinic stress group, sleep deprivation group and tank contral group.10 rats in each group.The depression animal model was established by chronic mild unpredictable stress(CUMS) methods.Sleep deprivation was preformed by the modified multiple platform method ( MMPM ).The animal model and the effect of antidepressant were evaluated by the open field test.The expression levels of Bcl-xl were separately observed by immunohistochemical technology in hippocampus CA1 ,CA3 and DG.Results 1.Compared with the normal control rats, ambulation ( 35.30 ± 18.77,81.30 ± 18.41, P ＜ 0.01 ) and rearing (20.50 ±4.84,27.70 ± 8.19, P＜0.05 ) increased ,and the stopping time in the center decreased (4.60 ± 1.35,2.20 ± 1.55, P ＜ 0.01 ) in the CUMS depressant animal model.2.The Bcl-xl average values of optical density (OD) in hippocampus CA1 ,CA3 ,DG of the model group was lower than that of the normal control group significantly (0.1356 ±0.0224,0.1389 ±0.0250,0.1457 ±0.0162;0.1725 ±0.0327,0.1734 ±0.0261,0.1768 ±0.0271; P＜0.01 ) ,and that of the sleep deprivation group was higher than that of the model group (0.1621 ± 0.0128,0.1603 ± 0.0137,0.1625 ± 0.0192 ;0.1356 ± 0.0224,0.1389 ± 0.0250,0.1457 ± 0.0162; P ＜ 0.05 ).Conclusion Rats showed depressive behaviors after 21 days stresses,while 72 hours sleep deprivation could reverse this effect.The up regulation of the expression and phosphorylation of Bcl-xl by sleep deprivation may participate in the antidepressant-like effect of sleep deprivation. Key words: Chronic unpredicted mild stress (GUMS); Sleep deprivation; Hippocampus; Bcl-xl