Effects of leptin on the anxiety behavior in REM sleep deprivated rats and its mechanisms

MA Wen-bin; HAN Xiao-feng; ZHENG Qi; CHEN Fang; LI Xi-zhi; GE Ru-li

doi:10.3969/j.issn.1002-266X.2014.44.015

Abstract：Objective To observe the effects of leptin on the anxiety behavior in REM sleep deprived rats, and to ex-plore its mechanisms.Methods A total of 90 male Wistar rats were randomly divided into 9 groups on average, as fol-lows:living together in home cage ( NS group) for 24, 72 and 120 h with NS,REM sleep deprived for 24,72 and 120 h with leptin ( L-SD group) or with NS ( NS-SD group) .The single platform ( SP) method was used to build the REM sleep deprivation model;the elevated plus-maze ( EPM) was used to assess the anxiety behavior;the RT-PCR method was used to measure the level of neuropeptide Y ( NPY) mRNA.Results At 24 h and 120 h, numbers of open arm ( OE) +closed arm (CE) in NS-SD and L-SD groups was higher than that in NS group (all P<0.01);the difference of OE+CE among 3 groups was not significant (P=0.47).At 120 h, compared with NS, OE ratio (OE%) and stay open arm ratio (OT%) increased in NS-SD group, but decreased in L-SD group, all P<0.01.At 120 h time point, OE%and OT%in NS-SD group were higher than those in 24 h and 72 h;but OE%and OT%at 120 h in L-SD group were lower than those in 24 h and 72 h;all P<0.01.Compared with NS group at the same time, NPY mRNA level in hypothalamus in NS-SD and L-SD groups increased (P<0.05 or P<0.01).At 24 h, 72 h, 120 h, NPY mRNA in NS-SD group increased gradu-ally, which in L-SD group decreased gradually, all P<0.05.Conclusion Chronic REM sleep deprivation could decrease the anxiety behavior in rats, but leptin could eliminate this effect;leptin inhibited the expression of NPY in hypothalamus might be one of its mechanisms.