London - Getting over jet lag could be as simple as flicking a light on, say scientists.
They claim to have found a master switch in the brain which can ‘reset’ the human body clock and which can be activated by beams of light.
The team from the US say the discovery could help us cope with long-haul travel or working irregular hours. Being able to reset the body’s biological clock could also lead to treatments for conditions such as seasonal affective disorder.
Initial tests on mice using optical lasers – high powered flashes of light shone into the eye – suggest the ‘reset button’ is in an area of the brain called the suprachiasmatic nucleus, says the team from Vanderbilt University in Nashville. Their results, published in the journal Nature Neuroscience, reveal that nocturnal mice they treated in this way became more active in the day.
Living things have an internal mechanism which synchronises their daily rhythms to the 24-hour pattern of the Earth’s rotation.
In humans and other mammals, this body clock is regulated by the senses, especially the way the eye perceives light. However, the pressures of modern life mean we increasingly risk our long-term health by working against this clock. Studies have found that those who work night shifts or who get too little sleep are more susceptible to conditions including depression, cancer and obesity.
Professor Douglas McMahon, who led the study, said: ‘We found we can change an animal’s sleep-wake rhythms by artificially stimulating the neurons in the master biological clock.’
The team found they could artificially make the nerve cells in that part of the brain fire whenever they wanted, making the mouse think it was time to be awake. They did this by genetically altering the cells to make them sensitive to light and then shining the laser into the eye.
Daily Mail