Still it cried "Sleep no more!" to all the house
"Glamis hath murder'd sleep and therefore Cawdor
Shall sleep no more, Macbeth shall sleep no more!"
(Macbeth Act 2, Scene 2)
Greed and ambition robbed Macbeth ( and his Lady too) of his sleep. Among other things it played havoc with his decision making capability and drove him to commit heinous crimes. Once mental peace is lost, sleep is hard to come and vice verse. , Then the vicious cycle starts and soon it is hard to say what was lost first, the sleep or the mental peace? And so we use a general term Stress . Sleep deprivation doesn't add up as in simple arithmetic, we need to resort to complex mathematics to see the cumulative effect. Recent issue of Nature (1) has a special section on Sleep.
Life evolved on earth with Sun the energy source as the sole reference point. Under nature's supervision work-life balance also evolved, day light hours for work and night for sleep and rest. The circadian clock was embedded in the suprachiasmatic nucleus (SCN), which took orders from the retina in the morning and responded to the melatonin level build up after sunset. Melatonin is secreted by the pineal gland which preferentially works during the night shift. Everything must have gone on well, till Prometheus stole fire from the heaven and man realized that fire could be used not only to cook delicious food and keep warm but also to light up the dark night. From then on we have been trying to extend daylight hours, literally burning the midnight oil to make the night as bright as the day could be and the advent of electricity was the greatest triumph of all. But that upset the carefully built in circadian clock within the human body.
The circadian clock is delicately balanced by the interplay of neurotransmitters such as acetylcholine, , orexin, noradrenalin, serotonin, histamine, dopamine etc during the " Arise awake" phase. When pineal gland senses no more light is coming through the retina, it starts secreting melatonin which in turn gives the signal for the build up of a simple molecule gamma amino butyric acid or GABA for short. GABA lulls us to sleep. But mind you, all these neurotransmitters hold several other jobs too. Professor Charles Cziesler is convinced that artificial lighting has interfered with this delicate balance. Retina perhaps never experiences total darkness and that impairs the build up of melatonin. and hence GABA. But can we go back in time to be cave men, hunting by the day and sleeping by the night? Of course not. Especially when we have learned to cross continents and time zones. So what is the quickfix? Sleep inducing pills? But they are not without side effects.
Macbeth couldn't do much to get back his sleep, but we could and should. Can we be coached and coaxed into better sleep behavior? Prof. Espie is exploring the possibility of putting Cognitive Behavioral Therapy (CBT) to use. He has developed an online program called the Sleepio which aims to do exactly the same. A good night's sleep could do wonders and could be a simple remedy for several ailments. That is why the crucial question of sleep hygiene is doing the rounds. To begin with, have you removed those audiovisual distractions from your bedside?
Reference
1. Sleep: Nature 23rd May 2013 vo. 497 pages S1-S20
