Objective:To observe the influences of sleep deprivation and antioxidant agent α-lipoic acid on the expression of IRE1 in the cortex and hippocampus in rats.Methods: Rats were randomly divided into control groups and sleep deprivation group.The control groups included blank control group (n=10) and environmental control group (n=10).Sleep deprivation group included 120 rats,and rats were further divided into α-lipoic acid group (25 mg·kg-1·d-1) and sleep deprivation model group.The two were further divided into 6 groups according to the periods of sleep deprivation and sleep restoration (SD 1 d,SD 3 d,SD 5 d,SD 7 d,SD 7 d/RS 6 h,SD 7 d/RS 12 h\[n＝10\]）.The expression of IRE1 mRNA and protein was examined by RT-PCR and immunohistochemistry,respectively.Results: RT-PCR results showed that the expression of IRE1 mRNA in the cortex and hippocampus were significantly higher in sleep deprivation group than in the blank and environmental control groups (P<0.05); there was no significant difference between the latter 2 groups.α-lipoic acid decreased the expression of IRE1.Expression of IRE1 between α-lipoic acid groups and sleep deprivation model groups was significantly different on SD 5 d,SD 7 d,SD 7 d/RS 6 h and SD 7 d/RS 12 h（P<0.05）.The immunohistochemistry results of IRE1 expression were consistant with RT-PCR results.Conclusion: α-lipoic acid can reduce the cerebral IRE1 expression in sleep deprivation rats,which provides a basis for antioxidant treatment of sleep deprivation.