Sleep is a very important aspect of our life that is grossly misunderstood, largely undervalued and as a result, ignored. This is fast turning into a major public health hazard due to our modern lifestyles.
Hence, we have brought you a series of articles that highlight sleep physiology, disorders, and modern treatment methods, based on a recent interview with the Medical Director of Indiana Sleep Centre (USA), Dr.Abhinav Singh.
Dr.Singh M.D, M.P.H, is board certified in Sleep and Internal medicine and is a Clinical Assistant Professor at Marian University where he developed and teaches a sleep medicine rotation. He is a sleep consultant for the professional basketball team - Indiana Pacers as well as a Medical review panelist at the National sleep foundation. His core passion is teaching students, residents, and anyone who is ready to listen, and says he didn't choose sleep medicine, it chose him.
We began the interview by talking about the discovery of the importance of sleep and the rising concern for various sleep disorders.
Dr.Singh quoted that until 3-4 decades ago, the significance of sleep was not well understood, but now we are waking up to the importance of sleep with the rise in the number of sleep-related disorders. Sleep constitutes a third of your life, and often, we deem it as a hindrance at best, as unproductive hours, however, he asks, does this assessment stand the test of reasoning? The whole notion of evolution is “don't get killed and make more of your own” and yet why do organisms across the animal kingdom put themselves at so much risk of getting killed by sleeping?
The answer lies in the fact that sleep involves so many vital phenomena that it is impossible for us to survive without adequate sleep.
When asked, how and when various stages of sleep were discovered,
Dr. Singh said in the 1930s, observations on changes in neuron firing patterns (brain waves) revealed that there is an increase in the amplitude and reduction in frequency at night and vice versa during the day. Later, contrary to prior expectations, researchers at the University of Chicago found that during sleep, at regular intervals, neurons were firing at a higher rate than in wake states. This led to the discovery of the REM(Rapid Eye Movement) sleep pattern in the mid 1950s.
A Brief talk on the physiology of sleep
On a typical night, there are four to five cycles of NREM (Non-Rapid Eye Movement )and REM sleep alternatively, with progressively deeper (less conscious activity) NREM sleep stages that makeup 75% of your sleep time and 25 % of REM sleep which occurs in the latter stages of the night (typically around 3 a.m -6 a.m for a person who falls asleep around 10 pm).
What are the events occurring in each stage of sleep?
Dr. Singh stated that, when you are asleep, memory and days’ cognitive activities are being analyzed, archived, and indexed from your working memory to long-term memory, akin to a computer which is processing and compiling data from temporary memory(RAM) to more organized long term memory (Hard Disk) and that’s why people who don't sleep well can be forgetful and have impaired short-term memory.
Further, during sleep, several hormones are released that are responsible for the growth, functioning, and repair of various cells, tissues, and muscles as each and every cell in our body from head to toe has a receptor that responds to sleep. This makes it even more important for kids and adolescents to get enough good quality sleep for developing healthy brains and bodies.
Why is it that the sound of something or a certain external factor puts one to sleep?
To this Dr. Singh answered, just as the intrinsic system of the body has a sleep-wake cycle, as in, the circadian rhythm, the body can get acclimated to an external environment for days, months, or years, such as a cozy bed with pillows and sheets, or the sound of a fan in one’s room. Some are used to reading a book before sleeping which helps them to fall asleep, while for some listening to pleasant music can put them to sleep. So the body gets used to such extrinsic factors that help one to fall asleep. As a result, it becomes a little difficult for some of us to fall asleep in a completely new environment for the initial few days.
How do dreams originate?
When asked about dreams, Dr. Singh commented that dreams occur in both NREM and REM sleep and that we dream the entire night, but we are mostly able to recall dreams that happen in the REM sleep. While it remains unclear but dream content is felt to arise from either fears or some unanswered questions or something fascinating one saw.
Does this mean the brain never stops thinking?
He stated that during sleep, active thought and sensorineural input do not happen because cortical arousals are largely dampened or blocked so that important physiological processes can take place intrinsically in the brain and body.
To conclude, It is important that one develops good sleep routines and habits to avoid not only sleep-related disorders but also other diseases involving cardiovascular systems such as hypertension, and coronary artery disease. Immunity can also get impaired when one doesn't have a proper sleep for 7-8 hours each day, increasing the vulnerability to immunodeficiency state and associated diseases.
Always develop regularity in your sleep such that every day you fall asleep at around the same time of the night and wake up at the same time of the day. Get good sunlight in the daytime to enhance wake and alertness and dim lights in the evening. Avoid screens such as mobile phones, Television, or computer around bedtime. Keep your surroundings cool while you fall asleep.
Last but not the least, if you wish to recall all the important things you have read or important events in your life that you’ve experienced, sleep well so that your brain can sort and file them up for you, and help you pick up any memory you want from your archives!
Stick around for the next article on factors influencing sleep, and how one can fix their sleep, especially for those working night shifts on a regular basis and sleep disorders.
Reviewed by Dr. Abhinav Singh M.D, M.P.H