Topic: hippocampal theta rhythms

The sleep stage in mammals consists of rapid eye movement (REM) sleep and non-REM (NREM) sleep. Each sleep stage has its own electrophysiological characteristics. For example, REM sleep is characterized by ponto-geniculo-occipital (PGO) waves in the brainstem and theta waves in the hippocampus, and NREM sleep by sharp wave-ripples (SWRs) in the hippocampus. These are thought to be important for memory processing. To date, however, their contributions to memory have been studied independently, and no studies have addressed the relationship between hippocampal neural activities and PGO waves. PG