New research from Oxford University has brought scientists closer to understanding the mysterious function of sleep. What the scientists have discovered is how oxidative stress leads to sleep. Oxidative stress is believed to be one of the reasons we age and is also a cause of degenerative diseases.
The study confirms just what scientists have suspected…chronic lack of sleep will shorten life. Professor Gero Miesenbock who led the team, compares oxygen tanks which carry explosion hazard labels to humans who face a similar risk when oxygen we breathe to convert food into energy leads to oxidative stress in cells. He calls this imperfectly contained combustion.
This oxidative stress is believed to be one of the causes of aging and associated degenerative diseases which hinder of later years in life. The new research shows that oxidative stress also activates neurons which control whether we go to sleep.
The research team studied sleep regulation in fruit flies which are the animals that provided the first insight into the circadian clock almost 50 years ago. Each individual fly has a special set of neurons which control sleep. In a previous study the team discovered that the sleep control neurons function like an on off switch. When the neurons are electrically active the fly will be sleeping. When the neurons are silent the fly is awake.
The team decided to look for the signals which will switch the sleep control neurons on. They knew from previous research that a major difference between waking and sleep is how much electrical current will flow through two ion channels which are called Sandman and Shaker. Most of the current will be through Shaker during sleep.The function of ion channels is to generate and control these electrical impulses through which brain cells will communicate. This made the team of scientists think about turning the question of, why we sleep, into a solvable and concrete problem. The team then sought to discovered what causes the electrical current to go through Shaker.
The answer was found in a component of the Shaker channel. They found that suspended below the electrically conducting portion of Shaker is another component. A small molecule, NADPH, flips back and forth between the chemical states which regulates the Shaker current. In turn, the state of NADPH reflects the degree of oxidative stress the cell has experienced. Sleeplessness leads to oxidative stress and this in turn drives the chemical conversion.
In a demonstration of this mechanism, a flash of light which flipped the chemical state of NADPH put flies to sleep.
Sleep disturbances are very common and sleeping pills are one of the most commonly prescribed drugs. These medications carry a variety of side effects and risks including addiction, forgetfulness and confusion. By targeting the mechanism the team has discovered, some of the side effects could be avoided.
To view the original scientific study click below.