Found one of the causes of dementia

Molecular biologists from the United States found that age-related weakening of delta rhythms, low-frequency brain waves, contributes to a slowdown in the circulation of cerebrospinal fluid and leads to an accelerated accumulation of protein “garbage” in the brain. This potentially explains the more frequent development of Alzheimer's disease and other forms of dementia in the elderly, writes sb.by.

As reported by TASS with reference to the press service of the Massachusetts Institute of technology, Professor of this educational institution Laura Lewis said: “Interestingly, in some of the older people we studied, these brain waves and the associated flow of cerebrospinal fluid were about the same as in healthy young people.” We are very interested in what distinguishes these people from their peers and how these differences can affect the subsequent aging of their body and nervous system.”.

Ten years ago, neuroscientists from the United States found that brain gamma waves with a frequency of 40 hertz help cleanse the nervous system of rodents from accumulations of the pathogenic protein beta-amyloid associated with the development of Alzheimer's disease. Subsequently, scientists confirmed the beneficial effect of these waves in experiments on volunteers, and also found that it is associated with the acceleration of the cycle of cerebrospinal fluid during sleep.

Scientists have found that in a similar way, another class of brain biorhythms, the so-called delta waves, affects the cycle of cerebrospinal fluid. These fluctuations with a frequency of 0.5 to 4 Hz are produced during the deepest phases of sleep, and their intensity decreases significantly as the body ages. This observation prompted scientists to test how delta rhythms affect the cycle of cerebrospinal fluid.

To do this, the researchers enlisted the support of 25 young volunteers and four dozen elderly people aged 60 to 84 years. Using the MRI system, scientists measured the brain activity of the subjects during sleep and tracked how the speed of movement of cerebrospinal fluid through the so-called glymphatic system changes. It is a set of channels through which the cerebrospinal fluid moves and which is involved in cleaning the brain of “garbage”.

These measurements showed that the speed of movement of cerebrospinal fluid in the elderly was significantly lower than in young volunteers, and this slowdown was generally consistent with how weak the delta waves in their brains were during sleep. Volunteers with weak delta rhythms also showed signs of mild brain atrophy, suggesting an important role for these fluctuations in maintaining nervous system health, the researchers concluded. How to Recognize Early Signs of Dementia and Why It’s Important to Get Tested