Studies in mice have shown that sleeping may become more difficult with age because the neurons that are responsible for regulating sleep and wakefulness become overactive.
Sleep deprivation is a major problem in the elderly. “More than 50 percent of people over the age of 65 are dissatisfied with the quality of their sleep,” said Luis de Lucia of Stanford University. Eighty percent of people with neurological disorders such as Alzheimer’s and Parkinson’s also have difficulty regulating their sleep and wakefulness. “This is a serious problem because sleep directly affects the quality of life and mood of people.”
Neurons and regulation of sleep and wakefulness
Lycia and colleagues developed a set of neurons in the hypothalamic part of the rat brain Decomposition and Analyzed Which produces a protein called “hypocretin”. In both humans and mice, these neurons are responsible for regulating sleep and wakefulness. Lycia and colleagues analyzed a set of neurons in the hypothalamus section of a mouse brain that produces a protein called hypocretin. These neurons are responsible for regulating sleep and wakefulness in both humans and mice.
The researchers suspected that these neurons could be effective in reducing the quality of sleep in the elderly because their number decreases with age. “As we age, about 20% of these neurons decline,” says Lycia. “This is common in humans and mice – although they have different sleeping habits.”
Comparing the neurons of old and young mice, the researchers found that with age, the remaining neurons become more stimulated and so-called inactive. Next, the mice were given drugs to reduce the activity of these neurons. Surprisingly, it was observed that the sleep quality of the mice improved after taking the drug.
“We do not know exactly what causes these neurons to become inactive,” says Lycia. “But because these neurons are shared between humans and mice, this research method can help us discover an effective drug for this problem.”
“The next step in studying this is to study the neural circuits in the brain that play a role in inducing us to feel sleepy,” says Renata Riha from the University of Edinburgh. “We have so far only looked at regulatory neurons, which are only part of the problem.”