Understanding the Basics of Sleep

A good night’s sleep has been linked to better health outcomes, including lower blood pressure and a stronger immune system. It’s also believed to aid in the production of memories, and a study found that people who miss out on slumber have a greater risk of developing mental health problems.

But scientists still don’t fully understand how and why the body and brain shut down during slumber. “Most of our understanding of sleep is like a partially assembled jigsaw puzzle,” says Mark Wu, a neuroscientist and a professor at Johns Hopkins University. “It’s not hard to see the pieces of sleep, but we don’t yet have a clear picture of how they fit together.”

The first stage of sleeping, known as onset or NREM, is a brief period during which the brain and body prepare for sleep. During this time, the EEG activity slows, responses to sensory stimulation decrease and the muscles become less active, although they may twitch slightly. The heart rate and breathing slow down as the body tries to conserve energy.

During this phase, the brain begins to generate slow waves that are generated at local cortical regions and not at a single point, as had been thought. These findings suggest that a global mechanism for the generation of sleep-related slow waves does not exist, but that individual cortical networks are able to initiate and regulate their own sleep (Krueger, 2010).

This onset or NREM phase is followed by rapid eye movements (REM), a more active stage during which the brain becomes more responsive to sensory inputs and arousal. The REM stage is associated with dreaming and a feeling of unreality, but it is not necessary for a normal night’s rest. Researchers have a number of theories about the purpose of REM sleep, such as its role in memory formation and emotional regulation.

It is also thought that REM sleep allows the brain to remove toxic substances from the blood and tissues, as well as recycle and repair cells. It is also important to the body’s immune system, as it helps the body to recognize and remember germs and other invaders.

A number of studies have shown that people who regularly skip out on sleep have higher risk factors for health conditions such as depression, high blood pressure and metabolic disorders. Sleep is so essential to our health that it should be a priority for all of us.

Aim for a full night’s sleep every day. Set a regular bedtime and wake-up time, and make sure to have a relaxing routine that includes warm showers or baths, deep breathing exercises and reading before you go to bed. Avoid caffeine, alcohol and heavy meals before going to sleep. And be sure to keep your bedroom dark, cool and quiet. It’s worth it. A good night’s sleep is key to a healthy, happy life.