In many ways we have come a long way as a social and technological species. It was only a century ago that you either needed a good pair of shoes or a healthy horse if you wanted to get somewhere. It was about the same amount of time ago that you needed to be in a room with someone if you wanted to talk to them. Along with all the technological change that has shaped so have our basic habits of daily living altered. Once upon a time people would repair things, like shoes and chairs, where now we just get a new one. In the evenings people would engage in outrageous activities like conversation, needlecraft, and games that engaged the mind like chess. Apparently, there was also a widespread hobby practised by many known as “sleepâ€. This “sleeping†involved lying down in a darkened room, closing the eyes, and entering a non-waking state for ten hours or more. It sounds bizarre to a post-modern mind just waiting to click through to the next screen but it might be something worth considering if, as two new studies suggest, this “sleep†thing can not only regenerate your brain but make you more attractive into the bargain.
The first study involved looking at mice and analysing gene activity of cells called oligodendrocytes in the cerebral cortex of mice that slept, and then comparing these with the gene activity of mice that stayed awake. Oligodendrocytes are cells responsible for making myelin within a healthy brain and in response to injury. Myelin is responsible for allowing electrical impulses to move from cell to cell like insulation around an electrical wire.
The study found that mice that slept, genes were turned on that triggered the formation of myelin. However, in the mice that stayed awake this triggered the genes involved in cell death and cellular stress response. Additionally, further analysis showed that cells that become oligodendrocytes, called oligodendrocyte precursor cells, double in reproduction during sleep. This reproduction is heightened during rapid eye movement (REM), which is linked to dreaming.
This shows that sleep does protect the brain at a basic level and suggests that extreme or chronic lack of sleep could trigger some symptoms associated with multiple sclerosis (MS), a progressive brain disease associated with myelin damage.
In the second study subjects were photographed on two separate occasions; on one occasion after eight hours of normal sleep and on the other after 31 hours continual sleep deprivation. The photographs were taken at 2.30pm on both occasions. Other participants then rated the photographs for facial cues, fatigue, and sadness. The face was the focus of this study because humans have a specialised neuronal network devoted to facial recognition and we use the face to make judgements of character and health.
The results showed that sleep deprived people were judged as having more hanging eyelids, redder eyes, more swollen eyes, and darker circles under the eyes. Sleep deprivation was also linked to paler skin, more wrinkles, and droopy mouth corners. People who lacked sleep also were judged as looking sadder.
If after all that you are still thinking that sleep just sounds like a waste of time then think of it this way, your regenerated brain will be better able to keep up with the fifty tweets that came through last minute on your Twitter feed and your freshened visage will make for a better profile picture on Facebook.
