In my related article The Science Of Sleep, I explain some of the key scientific principles behind sleep, whilst avoiding scientific jargon.
Just like a machine, if you understand how sleep works you will know how best to fix any problems.
Below is a summary of The Science Of Sleep for those of you who just want a basic knowledge without digging into the detail…
Information about light exposure is obtained by the hypothalamus which is a key factor in determining how our bodies operate around our 24-hour “body clock” or “circadian rhythm.”
When signals are received from the hypothalamus that light is fading the brain stem tells the body that it is time to relax.
When the pineal gland receives signals from the hypothalamus it starts to produce melatonin, the sleep- inviting hormone.
Acetylcholine and adenosine
The basal forebrain plays a key role in producing acetylcholine which promotes wakefulness; however, the presence of adenosine deters the release of acetylcholine and therefore leads to sleepiness.
Adenosine is the waste product of physical exercise. It suppresses arousal by combining with specific receptors in the brain, resulting in sleepiness and reducing the release of sleep-promoting acetylcholine.
Sleep can be hindered by the consumption of caffeine which competes for the same receptors as adenosine but doesn’t have the same arousal-suppressing qualities.
Stress, cortisol and the amygdala
Stress leads to increased cortisol levels in the body. In turn, this leads to increased amygdala activity – The fear centre.
When the ‘fear centre’ becomes overactive sleeping becomes difficult, leading to more stress and even more cortisol.
Such a vicious cycle can be extremely detrimental to your sleep and overall health.
The production of nitric oxide in the basal forebrain is considered to stimulate the release of adenosine, meaning the chemical is both necessary and sufficient to produce sleep.
This conclusion was met through a study of rats, as mentioned in The Science Of Sleep; therefore, make your own conclusions about the outcome.
If anyone knows of any similar experiments, conducted on humans, please let us know!
The thalamus, GABA and pituitary gland
The thalamus is responsible for “tuning-in” to your environment – the less sensory information available, the less the thalamus has to work with, the less likely you are to be woken up!
GABA is an inhibiting amino acid neurotransmitter that reduces brain activity. Many GABA supplements are available, but none are scientifically proven to improve sleep.
The pituitary gland is responsible for a lot of hormonal effects. Too much stimulation or damage to this gland can seriously impact on the quality and quantity of sleep you get.