The Semi-Interesting Neuroscience of Sleep Deprivation

Sleep deprivation is, for many, a seemingly unavoidable fact of life. An outcome of your body and mind having not rested for too long, its effects serve as a motivation for people to sleep before harm is done.

When a person is sleep deprived, most of the noticeable symptoms are caused by the body undergoing three different occurrences. One is that the body and mind are exhausted and thus work at a diminished speed and efficiency. The second is the body, in response to the reduced functionality, secretes stimulating hormones that combat enervation. Finally, the body releases an array of other chemicals, some of which cause noticeable feelings, and others that act unnoticed.

Sleep deprivation  drawing by Justin Peters '15

Sleep deprivation
drawing by Justin Peters ’15

Without rest, your body and mind do not function as well.  Sleep is an absolute necessity, and human beings will die if deprived of it for long enough. This direct need for sleep causes feelings of fatigue and a lack of motivation.

In response, the body tries to fight against the weakness caused by a lack of sleep by releasing chemicals that generally improve ones ability to function. Thyroid hormones, which are secreted into your bloodstream through the pituitary gland, play the most influential role in maintaining a person’s functionality. The hormones are carried to your brain in your bloodstream, where they cross the blood-brain barrier and then stimulate your central nervous system. This CNS stimulation causes some noticeable effects that improve your performance. In simpler terms, thyroid hormones, like caffeine, fight the direct effects of an exhausted brain and organs.

While thyroid is the most important hormone released, sleep deprivation also causes the levels of several other hormones to fluctuate. Leptin and ghrelin are both heavily affected, with levels of leptin decreasing and levels of ghrelin increasing. Leptin restrains hunger, while ghrelin increases the urge to eat. A new study revealed that sleep deprivation also lowers insulin levels by slowing production. Besides leptin, ghrelin, and insulin, multitudes of other chemicals are also released

Coffee is a common fatigue remedy for many. Caffeine, as previously mentioned, is a CNS stimulant that blocks adenosine receptors in the brain and other organs. Thus, the body doesn’t absorb the adenosine released by the body. Adenosine, which is a CNS depressant, is released in larger amounts during sleep deprivation, causing feelings of sluggishness and fatigue.  Caffeine also causes the body to release adrenaline, which increases one’s energy and heart rate.

So when you pay for a cup of coffee in the cafeteria, you’re also purchasing a short-term respite from the effects of sleep deprivation. Of course,  caffeine doesn’t combat all of the effects, which is why no amount Red Bull can make you feel truly well rested. Only one thing can do that: sleep.

LWHS’ own Winifred Montgomery, who has extensively researched and analyzed her own daily caffeine habit, spoke to me about her knowledge. She told me that “it improves your alertness, and it may have some impact on the speed of which you process. Certainly the evidence from my life says so.” In my own research, I found that, though caffeine can greatly improve the alertness of a person who is sleep deprived, it doesn’t accelerate the speed of which that person, in their sluggish mental state, can process information.

As a person continues to neglect sleep, caffeine’s ability to counter his or her fatigue decreases.  Montgomery explains that “You can do a short term reboot with coffee, but you cannot entirely give up sleep.” Eventually the body will no longer be able to go on. Attempts to stay awake, through environmental or chemical solutions, will fail. “When you have sleep debt, your brain will prioritize sleep over everything else.” explains Ms. Montgomery. This is for two reasons. One is that the body develops a short-term tolerance to the hormones and caffeine ingested as a person continues to utilize them. The second is that your body will, at some point, not be able to go on without rest. At the point of fainting, a person’s mind and body have been worn to the limit and cannot continue without rest. A condition called hypothyroidism will cause affected persons to faint sooner than those without it.

Sleep is a complex necessity and sleep deprivation a complex state of being. Science has only explained a portion of why and how sleep affects us, and I have only studied a small portion of what science has already discovered. The information in this article represents a miniscule understanding of sleep and sleep deprivation.


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