Effect of chronic sleep restriction on spatial learning and memory in infantile rats

Objective To study the effect of chronic sleep restriction (CSR) on spatial learning and memory ability in infantile rats. Methods Twenty-four male infantile SD rats at the age 1 month were randomly divided into CSR group, sleep deprivation (SD) group, and control group (8 in each group). Rats in CSR group and SD group underwent sleep restriction by gentle handing and multiple water platform techniques, respectively, 6 h a day for 5 days. Their spatial learning and memory ability were assessed by Morris water maze test before and 1, 3, 5 days after sleep intervention. Results Morris water maze test showed that the average latent period and distance were significantly longer in CSR group and SD group than in control group on days 3 and 5 after sleep intervention (P< 0.05), especially in SD group than in control group on day 5 after sleep intervention (P< 0.01). The latent period and distance were significantly longer in SD group than in CSR group on day 5 after sleep intervention (P< 0.05). Spatial probe test showed that the time in target quadrant (TTQ) and the number of platform crossings (NPC) were significantly lower in SD group than in CSR group and control group (P< 0.05). Conclusion CSR (6 h a day for 5 days) impairs the spatial learning and memory ability in infantile rats. However, its effect is ≤ that of sleep deprivation on the spatial learning and memory ability in infantile rats.