Sleep is controlled by two mechanisms: circadian and homeostatic circadian regulation. Our body clock, which is also known as a ‘circadian biological clock’, is controlled by approximately 20,000 cells in the suprachiasmatic nucleus, which is located in the hypothalamus of the brain. This mechanism is responsible for controlling hormones, sleep patterns and organ performance. The homeostatic circadian mechanism controls how much sleep our bodies require. Our daily circadian rhythm rises and dips at various stages throughout the day, making us feel alert, or tired.
Circadian rhythm can even be disrupted by the clocks going forward or back, and even these small changes that are implemented to our normal sleep pattern can have adverse effects because our bodies don’t adjust to the daylight saving time transition. Experts recommend that we should go to bed and wake up at the same time each night in order to synchronize our body clock. A culmination of late nights and early mornings can disrupt our natural body clock. Artificial light, using computers at night time and drinking excess amounts of caffeine can also alter our natural sleeping habits, but how much sleep we need is largely determined by our genes.
In 2001 scientists in the University of Utah discovered that a sleep gene referred to as hper2 predetermines our sleep preference. Early risers have a long gene, and those who prefer late nights have a gene which is shorter in length. There are only a small minority of people who are known as ‘short sleepers’, characterised by a gene called DEC2 which means a person won’t usually sleep for longer than a period of six hours per night, however experts say that a healthy adult requires 7 to 7.5 hours per night. Conversely, sleeping for too long can be detrimental because sleep is a form of sedentary behaviour and when the body spends up to ten hours inactive it can eventually cause cardiovascular problems.
1 in 10 of us are believed to be chronically sleep deprived which gives rise to a greater demand for sleeping pills. Insomnia is a growing problem in Britain, figures reveal that the NHS spent more than 50 billion on sleeping prescriptions this year alone. Sleeping tablets are highly addictive and they can be detrimental to our health. They can cause memory loss and even death. The pills mimic the body’s natural state of sleep through molecules, such as neurotransmitters and hormones which transport information to the brain and around the body. Sleeping tablets don’t work for everyone and over the past few years researchers have been providing insight into the cause of the sleeping conditions and looking into an improvement of contemporary tablets.
Image by Alex E. Proimos