Sleep crisis

This summer, we’ll all be sleeping a little less than we did the same time last year. In fact, the time we give to sleep has been steadily decreasing for thousands of years. Thanks to our 24/7 lifestyles, there’s so much to be getting on with that sleep seems like a waste of time. Wrong, says Dr Pierre Maquet of the Cyclotron Research Centre at Liège University: we need sleep – and we will soon be paying the price for not getting enough of it. Sleep, he says, is in crisis.

Recent research shows that Americans aren’t getting the recommended eight hours needed for good health, safety and “optimum performance”. One third gets less than seven hours a night. Europeans are only slightly better off. Most road accidents, when not due to alcohol, are down to lack of sleep. The nuclear disasters at Three Mile Island and Chernobyl have been ascribed to workers’ lack of sleep.

The mystery of why we sleep at all remains unsolved. Virtually every living creature on the planet does it, despite the fact that it makes animals temporarily vulnerable to predators and unable to feed. Ironically, the only animal believed not to sleep at all is the shark, which has no natural predators – and a very small brain. Most sharks need to keep moving in order to absorb oxygen. As mammals, dolphins would die if they slept and couldn’t occasionally come to the surface, so they’ve worked out a system whereby they put one half of the brain to sleep at a time. Deprive a rat of sleep for a few days, and it dies.

It is thought that humans used to spend most of their time asleep, like cats. All we needed to lead a fulfilled life was a couple of hours to hunt and eat and maybe an hour or so to make love and reproduce. But, at some point in our distant evolutionary past, we started to sleep less, probably as a result of increased social activity.

What is known is that sleep performs two functions: firstly, cell tissue is restored and toxins are eliminated from the body. More mysteriously, there are a whole bunch of learning and memorising processes going on – which is what Maquet is interested in.

The physical phenomena of sleep can be divided into two principle stages: Non-Rapid Eye Movement (NREM) and Rapid Eye Movement (REM). Typically, an adult enjoys 80 minutes of NREM sleep followed by around 10 minutes of REM, with this 90-minute cycle being repeated three to six times a night.

During NREM, brain activity, blood pressure and breathing slow down – basically, you’re out of it. REM sleep is typically associated with dreams: if you wake up during this, you will almost certainly remember what you were dreaming about. During REM, your body and brain seem to start up again – although you are physically paralysed and can’t act out your dreams. Sleepwalkers are thought to have a genetic disorder that prevents this paralysis. Your eyes flicker, as though you were watching a movie, hence REM. Interestingly, more than 50 percent of a new-born baby’s sleep is REM.

In French, REM is called sommeil paradoxal (paradoxical sleep) because when it was first discovered in the 1950s, scientists observed that, although the subject was asleep, his or her brain activity was similar to that when awake. Ever since, scientists have been trying to work out what exactly goes on during REM sleep.

Using positron-emission tomography (PET) scans, Maquet’s team can look inside the brain of a sleeper. Using their own particle accelerator, they create slightly radioactive water with a very short half-life (the time it takes for the substance’s radioactivity to reduce by half) which must then be injected into the subject, where it will show brain activity.

They submitted subjects to tests in which they had to respond to a light coming on in one of six positions. Sometimes the sequence of lights followed a pattern, or grammar, although this was not consciously recognisable as such. It was found that in subjects who had seen the pattern of lights, during REM sleep, particular parts of the brain associated with learning became active – and they performed the task a lot better the next day. The conclusion was that not only are memories formed during sleep, but a very active learning process is also taking place. For the first time, the old adage that a good night’s sleep is the best thing for you before an exam was scientifically confirmed.

While justifiably proud of his research, Maquet is also realistic about its applications. “There are none – yet. Our work has to be taken with that of twenty or thirty other labs around the world, and progress is slow. In physics, you can have one great idea that propels things forward by fifty years. Not in medicine.”

If and when their conclusions are applied, Maquet says, it is difficult to imagine the consequences. Current trends in psychoanalysis may be one of the first casualties. Despite mankind’s fascination with dream analysis, Freud and Jung’s theories are obsolete, as far as Maquet is concerned. “Freud talked about memory, but he didn’t know what we know about the different kinds of memory and the molecular processes behind them.

“If psychoanalysis were reborn it would be unrecognisable. You’d label molecules in the blood and do a PET scan, see what genes are in someone’s head which may be making them depressed, and prescribe them the appropriate drug,” he says. “Some time in the future, this will happen. However, listening to the patient will always be the first priority.”

The commercialisation of sleep is a more worrying prospect. “With the discovery of the genes that control sleep, we will be able to make people go to sleep at will and wake up when they want. Sleep and depression are also very much linked, so we may be able to control anti-depressive mechanisms. Companies in the US will want to copyright those genes, and sell them.”

Similarly, research has shown that women sleep better than men – and that they live around five years longer. Scientists at the University of Pennsylvania believe the two facts are connected, and that women sleep better because they have evolved habits to cope with crying babies and disturbed nights. Again, identification of the genes concerned would be a potential goldmine.

According to Maquet, the explosion of research into sleep over the last five years has not led politicians to study the impact of disturbances such as airports on local populations. “Look at the airport here at Beersel. It’s quiet between midnight and five in the morning, but that’s not enough. They’ve sacrificed the quality of life of hundreds of thousands of men and women for the sake of fifteen hundred jobs.” Combine that with the increase in shift work and you’ve got a good formula for disturbed sleep, depression and unproductiveness.

Sleep, it seems, is mankind’s most undervalued commodity. Maquet says that once the importance of sleep is acknowledged, governments may pass laws obliging you to sleep eight hours – or at least to stop planes roaring overhead at night.

But what happens in the plane’s cockpit is even more ominous. Belgian and US airforce pilots are known to have been given Modafinil, a drug developed for narcoleptics – people who may fall asleep at any moment – that enables the taker to stay awake for three consecutive days and nights without the side-effects associated with its predecessor, amphetamines. If such a product were to become widely available, everyone from cramming students to captains of industry would be clamouring for it – for themselves or for their workers. Worrying stuff. Just try not to lose any sleep over it.

© Charles Onians