Chronic intermittent hypoxia exposure induces memory impairment in growing rats

The study was aimed to examine the effect of chronic intermittent hypoxia (CIH) on spatial memory of growing rats and to explore the possible underlying mechanisms. Sixty two rats were trained to perform the 8-Arm radial maze task and were divided into four groups: 2-week-CIH (2IH), 2-week-control (2C), 4-week-CIH (4IH) and 4-week-control (4C). There were more reference memory errors, working memory errors and total memory errors in 2IH and 4IH groups compared to the controls. The levels of 8-iso-Prostaglandin F2α (8-ISO-PGF2α), an in vivo marker for oxidative stress, in serum, hippocampus and prefrontal cortex were higher in CIH groups than the control groups. There were significant correlations between the levels of 8-ISO-PGF2α and numbers of memory errors. The ultrastructural changes were evident in the hippocampal and prefrontal cortical tissues from the CIH groups. These results indicate that CIH can induce oxidative stress in brain tissues involved in spatial memory function.