Blue Light, Sleep Tight: Understanding of the Human Circadian Rhythm

Danial Asim

            Dr. Cavenaugh focused on understanding circadian rhythm in drosophila melanogaster. Understanding circadian rhythm is important because it suggests that the brain has an intrinsic way of figuring out when one should wake up or go to sleep. There have been extensive studies done attempting to detail the mechanism which incorporates all of the hormones and receptors involved in the circadian rhythm.

            In today’s society it is common to be on one’s phone for an hour before going to bed. While doing so may seem harmless, one begins to wonder whether there is a correlation between the amount of light one has and the difficulty one has in falling asleep. Indeed, insomnia is a growing problem in today’s society.

            LEDs have been used for years now at home, whether it is in in our smartphones and tablets or in a TV screen. A study suggests that LEDs can emit blue light. This blue light is hypothesized to affect physiological functions to both harm or improve our circadian rhythms. The concept of a controlled amount of blue light being able to improve our circadian rhythm is counterintuitive in that any type of light would theoretically distract one from falling asleep.

It has been shown through studies with mice that there are certain receptors which are activated when one is exposed to blue light which help kick start the mechanism for when one is attempting to sleep. However, this process is not as useful for older people. The following data shows that there is more mRNA present for proteins which induce/kick start the sleeping mechanism. Interestingly, both intensities of blue lights at a wave length of 474nm had the most mRNA. This mRNA was extracted from mice which were exposed to the respective light for 4 hours a day for 30 days.

            This could be because the receptors in our brain are not as reactive by being used over the years. Additionally, if blue light can be used to help kick start this mechanism then perhaps a controlled amount of it can be used as a therapy for people suffering from insomnia.

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734149/