What is sleep for? In our daily experience we know it as the period of rest that allows us to ‘recharge.’ It is the time needed to regenerate our brains and allow us to move out into the world once again, fresh and ready. As scientists continue to study in an attempt to understand what happens, and why, when we sleep; a new study shows that it allows our brain to regenerate brain cells.
A research group at the University of Wisconsin, in Madison, studied two groups of mice to see what genes are activated during sleep. For the group of mice that were allowed to sleep, it was found that a gene was activated that began a process of rebuilding the brain; specifically the myelin by creating oligodendrocyte precursor cells. Where the group that was denied sleep had a significant increase in stress response as well the hormones that break down the body. This finding has lead to the hypothesis that chronic lack of sleep may be a major contributing cause to the development of multiple sclerosis (MS), which is a dis-ease that breakdowns down myelin.
Myelin is the conductive and insulating material between neurons. It allows neurons, as well as the communication between them, to be faster and more efficient. It prevents the crossing of signals, much like insulation does for electrical wires. Oligodendrocyte cells are responsible for making the myelin throughout our nervous system. It was found that the production of the oligodendrocyte precursor significantly increased during REM (rapid eye movement) sleep.
It is interesting to note the generation of the oligodendrocyte precursor cells is increased during our deepest, most restful state of sleep. REM is also the state of sleep in which we dream and have the most neural activity. Interesting that the brain appears to be repaired during dreaming with so much activity in the brain.
To paraphrase Chiara Cirelli, an author of the study and a member of the Center for Sleep and Consciousness at the University of Wisconsin: most sleep research done up to this point, the focus had been on the differences of activity of nerve cells. Scientists looked at what the neural activity of waking verses sleeping brains was, but there was no research into how the nervous system operates. With this new study, it has been shown clearly that supporting cells also change how they function during sleep.
For many years, scientists thought that brain cells were not regenerated or reproduced during the course of someone’s life. The thought had been that after birth your brain has a finite number of cells that you would lose till the end of your life. While that theory has been changing in the last 12 years, this new study sheds some light not only on a reason for sleep, but that our brain goes through a daily process of regeneration and repair.
Perhaps this study will help shift our cultural ideas about sleep. It is not laziness that prompts our children to sleep long hours, but, perhaps, it is their brain processing information, integrating, and repairing itself for a new day. Perhaps the idea that it is a luxury to sleep ‘late’ can be replaced by understanding that allowing your body to get all the sleep it wants is a necessary and natural function. Yet, like most science, it takes time to filter into mainstream consciousness, but now we have more proof that sleep regenerates braincells.
By Iam Bloom