Torbjørn Gisleberg

Abstract

Sleep homeostasis models attempt to explain why and how the brain responds by increasing duration and intensity of sleep as a function of intensity and duration of prior wake. Several lines of research within this paradigm suggest a restorative metabolic function of sleep: restoring resources depleted during wake or clearing waste products that accumulate during wake. Increasingly, homeostatic sleep pressure is being viewed as accumulating at a higher rate during active waking, as compared to quiet waking. In addition, electroencephalographic markers of sleep homeostasis have also been shown to occur during quiet wakefulness. Finally, a handful of studies also suggests that some of the same restorative metabolic functions as in sleep may be effective during quiet wakefulness. These observations suggest an intriguing possibility that the homeostatic regulation of sleep is complimented by a similar regulation in quiet wakefulness. Here, this possibility is explored by developing and testing a homeostatic model of wakefulness. The model suggests that quiet wakefulness may increase the ability to sustain wakefulness. A hypothesis driven approach identified high intensity-, high frequency gamma as a possible marker of quiet wakefulness homeostatic regulation. This analysis represents a first attempt at identifying the hypothesized homeostatically regulated quiet wakefulness. The results were ambiguous, as the findings did not generalize to a larger sample of rats

Supervisor

Main supervisor   Janne Grønli