OBJECTIVEThe effects of sleep deprivation on the immature brain remain unknown. Based on a computer controlled chronic sleep deprivation animal model, the effects of chronic partial sleep deprivation on growth, learning and memory in young rats were explored.

METHODSTwelve weaned male Spraque-Dawley rats (3-week-old) were randomly divided into sleep deprivation, test control and blank control groups. Sleep deprivation was performed using computer-controlled "disc-over-water" technique at 8-11 am daily, for 14 days. The temperature and weights were measured every 7 days. Morris water maze was used to test spatial learning and memory abilities before and 7 and 14 days after sleep deprivation. After 14 days of sleep deprivation, the rats were sacrificed for weighting their major organs.

RESULTSAfter 14 days of sleep deprivation, the rats' temperature increased significantly. During the sleep deprivation, the rate of weight gain in the sleep deprivation group was much slower than that in the test control and blank control groups. The thymus of the rats subjected to sleep deprivation was much lighter than that of the blank control group. After 7 days of sleep deprivation, the rats showed slower acquisition of reference memory, but were capable of successfully performing the task by repeated exposure to the test. Such impairment of reference memory was not seen 14 days after sleep deprivation.

CONCLUSIONSChronic sleep deprivation can affect growth of immature rats, as well as their abilities to acquire spatial reference memory.