Sleep quality is associated with the ability to self-clean brain


O cerebrospinal fluid (CSF) or cerebrospinal fluid (LCE) is a normally clear, colorless liquid that bathes the brain and spinal cord responsible for nutrient distribution and waste disposal, glyphatic system– an extension of the lymphatic system, first described by Nedergaard and his colleagues in 2012 – through the entrance of the FCS along the perivascular and cerebral spaces.

This flow of cerebrospinal fluid through the glyph system depends on the aquaporin-4, (AQP4), a water-channel protein (plasma membrane protein that regulates the passage of water between the inside and outside of the cell) that is raised at the ends of the neuronal cells called astrocytes, which are in contact with blood vessels and spaces containing ECL.

It has been observed that the flow of the glyphatic system is affected by the type of brain waves produced, as in the case of slow waves (delta), which increase not only in animals that sleep naturally in the deep phase of non-REM sleep Eyes Movement), but also during the effects of ketamine / xylazine anesthesia, however, the underlying mechanisms that facilitate CSF flow and the importance of AQP4 are poorly understood.

to study

In a recent study, which appears in the journal Advances in Science,the researchers wanted to test the hypothesis that anesthesia could be used to manipulate both the electroencephalogram (EEG) spectrum and cardiopulmonary function and to regulate differentially the flow of the glyph system, for which experiments were performed on anesthetized mice with six different anesthetic regimens

While the animals were anesthetized, the scientific team tracked several parameters: brain electrical activity, cardiovascular activity, and cerebrospinal fluid clearing flow, measured by the analysis of the distribution of a fluorescent marker in different areas of the brain, obtained with different general anesthetics was used.

and brain cleansing mechanism

The results indicated that a combination of ketamine and xylazine (K / X) showed greater similarity to the slow electrical activity (delta) and constant brain waves and the slow heart rate associated with non-REM deep sleep, which proved to be optimal for the system function glyphs.

In a brief explanation of Maiken Nedergaard, Co-Director of the Translational Neuromedicine Center at Rochester University Medical Center (URMC) and lead author of the study:

"Sleep is fundamental to the function of the brain's waste disposal system and this study shows that the deeper the sleep, the better","These findings also increase the increasingly clear evidence that sleep quality or lack of sleep can predict the onset of Alzheimer's disease and dementia."

The researcher Lauren Hablitz refers to the chemical mechanisms involved in the electrochemical reactions related to the glyphic flow:

"Synchronized waves of neural activity during deep slow-wave sleep, specifically the trigger patterns that move from the front of the brain to the back, coincide with what we know about the flow of cerebrospinal fluid in the glyph system.","It seems that the chemicals involved in the firing of neurons, that is, the ions, lead to an osmosis process that helps extract the fluid through the brain tissue."

of results

It is known that as we age, it becomes more difficult to keep non-REM sleep constant, which helps maintain a good function of the glyph system. This has several relevant clinical implications, such as the link between sleep, aging and Alzheimer's disease, which is associated with the accumulation of toxic proteins such as beta amyloid and tau at the brain level, which is why several researchers have suggested that the insufficient function of the glyphic system due to sleep interruption could act as a determining factor for this pathology . These findings are related to clinical observations that associate sleep deprivation and an increased risk of Alzheimer's disease.

The findings may also explain why certain anesthetics may lead to cognitive decline in older adults, which corresponds to those who did not induce slow brain waves and decreased gliptic activity, as indicated by Tuomas Lilius of the Center for Translational Neuromedicine at the University of Copenhagen . in Denmark and co-author of the study:

"Cognitive impairment after anesthesia and surgery is a major problem""A significant percentage of elderly patients undergoing surgery experience a postoperative period of delirium or have new or worsened cognitive impairment on discharge"

As a clinical application, this study also
shows that the glyph system may
improve the quality of
to sleep
, such as through the use of sleep therapy or other treatments,
especially for populations at risk of suffering
neurological pathologies that are affected by sleep disorders.

Original Note: Rochester University Medical Center


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