Why do people sleep so badly in old age?
Many older people have problems sleeping properly at night. Researchers found that age affects the ability of the so-called circadian clock in mammals to readjust when exposed to light. This then leads to a disturbance in the sleep pattern.
In their current joint study, scientists from the University of Kent and the University of Greenwich found out why many older people have problems with their sleep. The doctors published the results of their study in the English-language journal "Neurobiology of Aging".
Photosensitivity of the suprachiasmatic nucleus changes
The University of Kent Medway School of Pharmacy experts looked for changes in the brains of older people that affect their sleep patterns. The results showed that photosensitivity in a certain part of the brain decreased significantly with age. The affected section called the suprachiasmatic nucleus controls the so-called circadian rhythms in mammals.
Effects of the impaired sensitivity to light
If the photosensitivity of the suprachiasmatic nucleus is reduced, this leads to a disturbance of the sleep pattern and thus to a risk to wellbeing. This breakthrough in understanding sleep problems could lead to future treatments being developed that aim to restore the circadian clock, the researchers hope.
Glutamate receptor worked less effectively in old age
In their investigation, the experts found that a so-called glutamate receptor (NMDA), which is used to transmit light information, became less effective in resetting the circadian clock in the course of the aging process, explains Dr. Gurprit Lall of the Medway School of Pharmacy in a press release.
Any changes found are age-related
This structural change in the glutamate receptor was responsible for the observed decrease in the light response. A subunit of the NMDA receptor had a significantly reduced presence in older mammals, which indicates an age-related change in the structural configuration, Dr. Gurprit Lall.
Structural reorganization leads to problems
The study concluded that an aging suprachiasmatic nucleus suffers from a structural reorganization of its light-receiving components. Ultimately, this affects the function of setting and maintaining a stable circadian rhythm, say the doctors. (as)