Brain Patterns of Sleep During Sleep Deprivation: An Animal Study

Ordinarily, during awake times, brain waves are relatively fast and of low amplitude, different from the slow, high-amplitude, non–rapid eye movement sleep patterns on electroencephalography (EEG). But most people have noticed times during sleep deprivation when parts of their brain seem to be “foggy,” even when they are not feeling sleepy. To examine this phenomenon, researchers measured brain activity during and after sleep deprivation in rats.

EEG and local field potential (LFP) electrode arrays were implanted in frontal and parietal cortices. For sleep deprivation, rats were kept awake (via exposure to novel objects) for 4 hours past their usual bedtimes. Measurements continued for 10 hours, including 6 hours of post-deprivation sleep. T…