No abstract

Purpose It is well established that loss of sleep leads to lapses in learning and memory. The brain regions including hippocampus, amygdala and the prefrontal cortex are associated with memory processes. However, there are not many studies on the changes in neuronal communications between these brain areas during sleep deprivation. Methods In this study, changes in the P waves, and theta coherence among the hippocampus, amygdala and the prefrontal cortex, were studied before and after exposing the animals to total sleep deprivation of 24 h. Changes in reference and working memory were evaluated after sleep deprivation.Results Concomitant with a rebound increase in non-REM sleep after total sleep deprivation, there was a decrease in the coherence of theta waves between all the studied areas, especially between hippocampus and amygdala. The ratio of P wave cluster to singlet was reduced. There was a decrease in 'correct memory performance' after sleep deprivation. Conclusions This study showed that after sleep deprivation, there was a correlation in the cognitive deficits and decrease in the coherence of theta waves, and the ratio of P wave cluster to singlet. Impairments in brain function, especially cognition, after sleep loss could be attributed to changes in functional connectivity between these neural networks. This study highlighted important functions of sleep in maintaining an appropriate synchrony between various neuronal networks during REM sleep.