Why do we sleep?

A paper from my Uni days: NEUR 3750

Russell Foster, Neuroscientist (circadian rhythms)

The human who reaches the age of 90 will have spent 32 years of those ninety entirely asleep. It is as important, if not more so, than it is consuming. In fact, this 36% of our lives is the single most important behavioral experience we have. Why then have we adopted Thomas Edison’s outlook, that sleep is ‘a criminal waste of time, inherited from our cave days’? Is sleep not important at some level?

𝘚𝘭𝘦𝘦𝘱 𝘪𝘴 𝘧𝘰𝘳 𝘸𝘪𝘮𝘱𝘴 - 𝘔𝘢𝘳𝘨𝘳𝘦𝘵 𝘛𝘩𝘢𝘵𝘤𝘩𝘦𝘳

𝘔𝘰𝘯𝘦𝘺 𝘯𝘦𝘷𝘦𝘳 𝘴𝘭𝘦𝘦𝘱𝘴

Sleep has gone in & out of fashion over time, at first glance it isn’t productive, but is it really just a luxury? These days it seems that we have used Thomas Edison’s light bulb to occupy the dark, acting as though sleep is some sort of illness. So why do we abandon sleep? Some believe that sleep simply helps us conserve energy & recover (in reality the difference in calories between the sedentary person & the one asleep is 110 calories), it is also known to be needed for restoration & maintenance (replace and rebuild) but there’s more to it than that. In fact, there are a whole raft of genes that are only ‘turned on’ when you’re asleep.

𝘚𝘭𝘦𝘦𝘱, 𝘰𝘩 𝘨𝘦𝘯𝘵𝘭𝘦 𝘴𝘭𝘦𝘦𝘱, 𝘯𝘢𝘵𝘶𝘳𝘦’𝘴 𝘴𝘰𝘧𝘵 𝘯𝘶𝘳𝘴𝘦 𝘩𝘰𝘸 𝘩𝘢𝘷𝘦 𝘐 𝘧𝘳𝘪𝘨𝘩𝘵𝘦𝘯𝘦𝘥 𝘵𝘩𝘦𝘦 - 𝘚𝘩𝘢𝘬𝘦𝘴𝘱𝘦𝘢𝘳𝘦

Once upon a time the average for the human population was 8 hours (what is needed), today it is closer to 5. Micro sleeps…It’s happened to most, if not all of us, when we are sleep deprived we fall asleep involuntarily, which can be a disaster if we are driving…then there’s the poor memory, poor creativity, increased impulsiveness, poor judgement, sustained stress, the list goes on. Sleep loss leads to low immunity, which leads to cancer, increased weight gain (sleep deprived people are 50% more likely to be obese) due to the hormone ghrelin, glucose resistance witch can lead to diabetes II, & a higher risk of cardiovascular disease. It is important to point out that the neural networks responsible for mental health are overlapping with the ones responsible for normal sleep, in other words, sleep disruption precedes mental disruption.

If so much harm can arise from sleep deprivation it must be important to our brain. As mentioned above there are certain parts of the brain that are only active during the sleep state. It should be obvious now that sleep is essential to brain function, especially when it comes to processing, creativity & memory consolidation. Task learning is smashed in sleep deprived individuals, as is the ability to find novel solutions to complex problems. It would make sense then, that something so seemingly complicated would not arise from one structure, but from a whole raft of different interactions in the brain that are responsible for sleep.

Basically, the hypothalamus (the body’s biological clock) has projections in to the brain stem which bathes the cortex. So what can we do?

𝘌𝘯𝘫𝘰𝘺 𝘵𝘩𝘦 𝘩𝘰𝘯𝘦𝘺 𝘩𝘦𝘢𝘷𝘺 𝘥𝘦𝘸 𝘰𝘧 𝘴𝘭𝘶𝘮𝘣𝘦𝘳 - 𝘚𝘩𝘢𝘬𝘦𝘴𝘱𝘦𝘢𝘳𝘦’𝘴 𝘑𝘶𝘭𝘪𝘶𝘴 𝘊𝘢𝘦𝘴𝘢𝘦𝘳

Many try to cope with a tired brain by using stimulants to fuel the waking state, then at night, alcohol as a sedative. The problem with alcohol is that while it may bring the body ‘down’, it is harmful to the much needed neural processing that takes place in the sleep state. Instead the individual seeking a better nights sleep should make the bedroom a haven for sleep; dark, slightly cool, 30 minutes before they plan to go to bed light exposure (to include electronics) should be decreased. No stimulants should be taken after lunch time and biological light should be sought out first thing in the morning, as it helps to set the biological clock.

𝘐𝘧 𝘺𝘰𝘶 𝘥𝘰𝘯’𝘵 𝘴𝘭𝘦𝘦𝘱, 𝘺𝘰𝘶 𝘤𝘢𝘯’𝘵 𝘧𝘭𝘺

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