Effects Of Sleep Deprivation On Postoperative Cognition And Hippocampal BDNF/PSD-95/p-CREB Expression In Mice

Part ⅠObjective:To investigate the effects of different sleep deprivation time on spontaneous activity and cognitive function in mice and to provide a model for studying the impact of preoperative sleep deprivation on postoperative cognitive function.Methods:Sixty adult C57BL/6 male mice were randomly divided into six groups,ten mice were in each group.The modified multiple platform method were used to establish REM SD model except in control group.OFT were used to assess spontaneous locomotor activity and NOR were used to assess cognitive function.Results:Compared with Con group,there was no difference in the line crossing,the time of the peripheral quadrant,and the recognition index between T1 group,T2 group,and T3 group(P>0.05).The number of line crossing(P<0.01)and recognition index(P<0.01)were significantly reduced in groupT4,but there was no significant difference in the time of the peripheral quadrant(P>0.05).The number of line crossing was reduced(P<0.01)and the duration of the peripheral quadrant was increased(P<0.05)in group T5,but the recognition index was not statistically different(P>0.05).Conclusion:The model of SD 3 days was more suitable for the study of the impact of preoperative sleep deprivation on postoperative cognitive function.Part ⅡObjective:To ascertain whether preoperative sleep deprivation causes postoperative cognitive dysfunction and to detect the change of BDNF,PSD-95 and p-CREB in hippocampus.Methods:Sixty four adult C57BL/6 male mice were randomly divided into 4 groups,sixteen mice were in each group.The modified multiple platform method were used to establish REM SD model in group SD and SD+Sur.Exploratory laparotomy were used to establish surgical model in group Sur and SD+Sur.Open field test were used to assess spontaneous locomotor activity;Morris water maze and novel object recognition test were used to assess cognitive function.The change of BDNF,PSD-95 and p-CREB in hippocampus were measured by Western blot.Results:Sleep deprivation and surgery had no significant effect on spontaneous activity in mice respectively(P>0.05).Compared with Sur group,preoperative SD decreased the recognition index in NOR(P<0.01);increased the escape latency(P<0.01)and reduced the percentage of target quadrant time(P<0.05)in the MWM,but had no reduction on platform crossing times(P>0.05).Preoperative SD did not change the expression of BDNF in the hippocampus of mice after surgery(P>0.05),but the expression PSD-95(P<0.01)and p-CREB(P<0.05)were significantly decreased.Conclusion:Preoperative Sleep deprivation impaired postoperative learning and memory ability.The mechanism may be related to the decrease in PSD-95 and p-CREB in hippocampus.