Characterization of Maze Performance in Adrenalectomized Sleep Disrupted Rats: A Comparison of Radial Arm Maze Performance between Adrenalectomized and Sham Adrenalectomized Sleep Disrupted Rats

摘要

Sleep disruption affects performance in rats in several behavioral paradigms. Elevation of plasma corticosterine is associated with stress, and with sleep disruption in rats. Elevated corticosterone may contribute to dendritic regression in the hippocampus, a brain region associated with spatial learning. The working hypothesis of this study was removing adrenal glands in a rat will ameliorate the effects of sleep disruption on maze performance. Animals adrenalectomized and sham adrenalectomized were trained to criterion in the eight arm radial maze, and sleep disrupted for 12 hours during the light phase using a modified flowerpot in a cage with an inch of water. Removal of adrenal glands improved post sleep disruption performance slightly, but not significantly. However, the Barnes maze results showed an improvement of performance with a glucocorticoid receptor antagonist given 4 hours before the conclusion of 12 hours of sleep disruption on the flowerpot the post sleep disruption performances were compared. In addition, animals were implanted with a venous jugular catheter and sampled over a 36 hour period which included 12 hours of recovery. The results showed a significant elevation of corticosterone during the period of sleep disruption with recovery to cage control levels within 4 hours after return to home cage. In conclusion the sum of the performance impairments associated with sleep disruption may be the result of elevated corticosterone.