In the Sandman’s absence, a black hole of loneliness, jealousy, and sadness can take hold. The average individual requires 7 to 8.5 hours of sleep in a 24 hour period. The time needed for rest varies on the individual and the amount of external information entering the brain at a time. Sleep regulates a multitude of bodily functions such as body temperature, mood, learning and memory, and immune system; however, the effects of insomnia or nightly lack of sleep vary between individual.
What determines the amount of sleep needed from individual to individual?
Sleep required is variable, some studies suggest rest is necessary to resolve the waste of the brain’s metabolism and solidify neuronal connections. Other theories suggest this is a simplistic viewpoint for the intricate workings of the brain.
How does the brain tire out? Why do we tend to have more energy when we are unchallenged in a day?
Studies conducted by Michel Siffre may shed some light on the question. Michel Siffre lived in a subterranean cave in isolation for two months in 1962; and spent time reading books and articles away from human-conceived time. He found through his study, and other studies, that although the human body seemed to have an innate biological 24-hour clock, independent of light-dark periods, it is based on the amount of mental activity the individual requires. For example, some test subjects were able to attain 48 hours “days” in which an individual was active for 36 hours and slept for 12 to 14 hours. Based on tests of two other subjects in isolation in caves, Siffre found that every ten extra minutes of activity spent, one additional minute of REM sleep tacked on for that night.
Similarly, a study conducted by Karim Alkadhi, et al. found that the amount of sleep required is inversely related to the basal metabolic rate of the brain. Is our rest correlated to the amount of metabolic strain on our minds in just everyday life? Could our brains be worn out from all the external stimulation from daily life resulting in our need for drugs to stay awake? Studies on university students found the most common reasons for poor sleep was related to technology, alcohol, stimulants, and caffeine. Additionally, sleep deprivation in the first year of college was a precursor to a low GPA.
What parts of the brain control sleep? Why does the brain “malfunction” when slumber is missed?
Although there is some debate as to whether sleep causes deficits in reaction time versus processing skills, a recent fMRI study suggests sleep decreases the efficiency of certain parts of the brain, while increasing efficiency in others. Meanwhile, sleep deprivation can cause other effects throughout the body:
- Deficits in homeostasis reestablishment post-threat/during exercise
pro-inflammatory responses increasing: tumor necrosis factor, IL-6 release, C-reactive protein
Each sleep stage possesses a particular cellular and anatomical structure -each sleep stage has a specific function
To make this post easier to digest, I created bullet points to breakdown the overall effects of sleep deprivation for further discussion below.
- Increase in corticosterone and ACTH
- Increase in Na-K-ATPase activity in the brainstem & cerebellum
- Metabolic disturbances in the hippocampus, prefrontal cortex, & amygdala
- Delta and theta wave activity during waking hours
- Reduction of glucose metabolism 6-8% globally in the brain
- However, a 15% reduction of glucose metabolism in the prefrontal cortex, frontal cortex, and thalamus
- Reduction of oxidative damage caused by metabolism during waking hours
- Inhibition of hippocampal cell proliferation and neurogenesis
- Global efficiency in processing time decreased, however, increased efficiency in specific areas of the brain
- Efficiency decrease in the anterior cingulate, the inferior parietal gyrus, the caudate nucleus, the and the thalamus
- Efficiency increase in the temporal gyrus and more activity seen in the prefrontal cortex
What does this all mean? (the technical stuff)
Your crankiness and attitude towards other people is your brain crying out for sleep! Corticosterone is a hormone which can either be a glucocorticoid, a sex hormone or a mineralocorticoid. Fundamentally, corticosterone can affect stress, hormone levels, mineral or metabolism levels in the body according to the way it affects the hypothalamus. ACTH is an abbreviation for adrenocorticotropic (ACT) hormone which is released in the pituitary gland in response to excitation of the hypothalamus by corticosterone. ACTH stimulates the pituitary gland to release glucocorticoids. Glucocorticoids affect cell metabolism, neuronal plasticity, stimulation or inhibition of specific gene transcription, and immune response inhibition to name a few.
Concerning delta and theta waves, there are five waves the brain shows during electroencephalography. The delta wave (see picture below) is associated with deep sleep. Theta waves are associated with emotional processing communication between the frontal lobes and the limbic system and memory performance and low brain activities. Alpha waves are related to the inhibition of specific brain areas which includes calmness and alertness; beta waves are focused activity and cognitive tasks, gamma waves and associated with events of “higher moral” levels.
The hippocampus is the center of the brain responsible for memory retention. The amygdala is for threat and emotional processing. the Prefrontal cortex is for judgment, essentially the “conscience” of the brain. The thalamus is responsible for the regulation of sensory information entering the brain into consciousness. The cerebellum is the densest neuronal area of the brain and is responsible for posture, refined motor skills, and balance; however, some believe it has more functions that are unknown so far.
The caudate nucleus is a part of the basal ganglia, responsible for movement. The temporal gyrus is located in the temporal lobe and is responsible for sound interpretation and processing. Similarly, the inferior parietal gyrus in the parietal lobe is also affected, which is responsible for language and mathematical operations. The previous descriptions of anatomical brain areas are shortened versions of each respective role. Some information may be missing to maintain conciseness in this post.
Why this subject?
I work and go to school through the week, usually with only Sundays as my days off, and I feel the strain just on 8 hours of sleep. My caffeine addiction, which I don’t need otherwise, becomes much worse than when I have rest. Once I’m home from a 9 hour day at work I either continue my work on paintings or school work. Typically on Sundays, I can sleep 15 hours and still want more time. Interestingly as the work week continues and my sleep credit racks up, I become irritable, sensitive to light and noise, despondent, tremendous confidence drops and, in extreme cases, hear and see sounds or objects not in my external environment. As much as I know this is an unhealthy state, I demand it.
Would I trade my 16 hour work days and 8 hours of sleep for 36 hours straight of activity and 14 hours of sleep? Yes, I think anyone would. Life’s fastpaced environment and demands for success, or perhaps my desires for success, require sacrifice. I either sacrifice my workout time, which keeps me healthy, for sleep; or sacrifice my sleep for exercise. Work is less negotiable on times I can attend versus rest. Which begs the question: for whom am I living? Myself, or the company I am employed? Am I happy in the job I currently work in? Or, would I rather lose sleep over a job I feel passionate about?
I hope you enjoyed this post because I did lose sleep over it! Any questions or comments on material or sources, please feel free to email me!