Scientists from the University of Kent have found out why people find it more difficult to sleep properly at night as they get older. The research results are published in the journal Neurobiology of Aging.
It turned out that over the years, mammals have decreased sensitivity to light in the suprachiasmatic nucleus, the part of the brain that generates circadian rhythms and synchronizes the work of the body's "biological clock".
Scientists put experiments on mice, first combined into groups of four, then on each separately. “Young” were one to two months old, “old” - from 14 to 18 months.
Light was directed at the cells with the rodents. It turned out that in "old" mice in the so-called glutamate receptor (NMDA receptor), which is used to transmit light information, the ability to "restart" circadian rhythms has significantly decreased. This is due to the fact that, due to age-related structural changes in the receptor, it reacts worse to light.
As a result, such changes lead to the inability of the suprachiasmatic nucleus to stably maintain circadian rhythms and, accordingly, to sleep disorders.
The scientists emphasize that their research could help treat older people who need to "reset" their biological clock.