Did you ever ask yourself why do we sleep, how sleep evolved, what are the anatomical and biochemical basis of sleep? Find out in part 1 of this exploration of Sleep.
- Almost all species studied engage in sleep; however how and why sleep evolved is under current investigation and has not been completely unraveled.
- Different species have evolved different patterns of sleep. For example, dolphins and migratory birds engage in uni-hemispheric sleep.
- The sleep cycle consists of rapid eye movement (REM) sleep and non-REM (NREM) sleep; these phases of sleep can be studied using electroencephalogram (EEG) and behavioral patterns.
- There are several neurotransmitters such as acetylcholine, noradrenaline, gamma aminobutyric acid (GABA), and galanin that are involved in sleep and wakefulness.
- Regions of the brain such as the cerebral cortex, pons, hypothalamus work together to create a state of sleep.
- Scientists have suggested several reasons why sleep is critical: for rest and repair, for memory consolidation, clearance of brain waste products, and for effects on the immune system.