Sleep deprivation increases the activation of nuclear factor kappa B in lateral hypothalamic cells

Abstract

Sleep deprivation increases sleep propensity in rats and mice as well as the production of several sleep-regulatory substances. Nuclear factor kappa B (NF-κB) is a transcription factor implicated in the activation of many of these sleep-promoting substances. A unique population of neurons immunoreactive for the p65 subunit of NF-κB was previously localized within the caudal dorsolateral hypothalamus of rats. Therefore, we evaluated the effect of sleep deprivation on NF-κBp65-immunoreactivity (IR) in cells of this region in rats as well as its nuclear translocation in a κB-lacZ transgenic mouse line. In rats after 6 h of sleep deprivation beginning at light onset, the number of neurons with NF-κBp65-IR increased significantly in the caudal lateral hypothalamus, specifically the magnocellular lateral hypothalamus adjacent to the subthalamus. Sleep deprivation also significantly increased the number of cells expressing NF-κB-dependent β-galactosidase in the magnocellular lateral hypothalamus, zona incerta dorsal, as well as the adjacent subthalamus in the transgenic mice. These results suggest that NF-κB expressing cells within the lateral hypothalamus may be important in the maintenance of the sleep-wake cycle. © 2004 Elsevier B.V. All rights reserved.