SIMPLY turning up the lights during the day might help elderly people sleep
better. Difficulty sleeping is one of the main reasons people over 65 visit the
doctor, so if the trick works, it could have big benefits.
Stephany Biello of the University of Glasgow got the idea after studying the
activity patterns of ageing hamsters. She found that their sleep became
increasingly disrupted as their internal body clocks deteriorated. 鈥淛ust like
humans, they sleep badly, wake up earlier and nap a lot,鈥� Biello says.
But she found that sleep quality could be improved in some animals. By simply
increasing light levels during the day, Biello restored normal sleep in hamsters
whose body clocks had only just begun to decline. 鈥淭his has big implications for
old people who don鈥檛 get outside much and so don鈥檛 see a lot of light,鈥� she
says.
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Biello thinks that light and dark signals are not processed as well in the
hypothalamus, a part of the brain that helps control the body clock.
Turning up the lights didn鈥檛 work for very old hamsters. But Biello found
that injections of brain-derived neural growth factor (BDNF) did restore their
clock function. 鈥淲e don鈥檛 know why it鈥檚 working,鈥� she says. It may be improving
nerve connections in the hypothalamus or increasing the ability of receptors to
respond to light and dark signals from the eyes, Biello suggests.
Clive Coen, an expert on biological clocks at King鈥檚 College, London, says
the implications could be far reaching. 鈥淚f BDNF works here it may be revamping
other [neural] systems as well,鈥� he says.