Sleep and the Brain

New research from the University of Rochester, published today, reconfirms the importance of sleep for brain health.

Their results, published in Science, show that during sleep a plumbing system called the glymphatic system may open, letting fluid flow rapidly through the brain. Dr. Nedergaard's lab recently discovered the glymphatic system helps control the flow of cerebrospinal fluid (CSF), a clear liquid surrounding the brain and spinal cord."It's as if Dr. Nedergaard and her colleagues have uncovered a network of hidden caves and these exciting results highlight the potential importance of the network in normal brain function," said Roderick Corriveau, Ph.D., a program director at NINDS.

A few years ago, I first wrote about REM sleep and brain oxygenation. After venoplasty and restoration of jugular, rather than collateral venous flow,  my husband Jeff had a return of dreaming and restful sleep.  Now that his jugular veins had been repaired, they were the major route of venous return for his brain while he slept, and the changes for him were immense and immediate.  After coming home from his procedure at Stanford, he no longer had night time spasms or fits of apnea, when he would literally wake up, gasping for air.  He now slept through the night, and woke refreshed.  He could now recount his very vivid dreams to me.   This was all new for him.

When I attended the first CCSVI conference in Bologna in 2009, I heard Dr. Salvi talk about the restoration of REM sleep and dreaming in Italian patients that had been treated for CCSVI.  It was the first intimation that something vital was happening to Jeff's brain while he was in deep sleep.  Here is my post on this topic, with research on oxygenation of the brain during sleep--
http://ccsviinms.blogspot.com/2010/09/to-sleep-perchance-to-oxygenate.html#more

Earlier this year, a new study from the University of Wisconsin showed us why sleep is essential for remyelination of the brain and synthesis of oligodendrocyte precursor cells.

They found that during sleep, hundreds of transcripts that govern the synthesis of cells called oligodendrocyte precursor cells (OPCs) are up-regulated during sleep, while genes involved in cell death, cell stress response and cell differentiation are up-regulated during wake. An assay of living cells confirmed that OPC proliferation doubles during sleep, especially during rapid eye movement phase (REM sleep) associated with dreaming.
http://www.med.wisc.edu/news-events/sleep-produces-cells-that-grow-and-repair-nerve-cell-insulation-/41696
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And today, a new study from the University of Rochester helps us understand the different functions the brain performs during sleep and wake, and why sleep is essential.  
http://www.eurekalert.org/pub_releases/2013-10/nion-bmf101713.php

In findings that give fresh meaning to the old adage that a good night's sleep clears the mind, a new study shows that a recently discovered system that flushes waste from the brain is primarily active during sleep. This revelation could transform scientists' understanding of the biological purpose of sleep and point to new ways to treat neurological disorders.

The University of Rochester researchers have been studying how the brain cleans waste during sleep, and they have named this process the "glymphatic system", because it combines the lymph process of cleansing and glial cells.  This system is like "a plumbing system that piggybacks on the brain's blood vessels and pumps cerebral spinal fluid (CSF) through the brain's tissue, flushing waste back into the circulatory system where it eventually makes its way to the general blood circulation system and, ultimately, the liver."

Time for the BIG picture. When we lie down, our cerebral circulation changes.  This is, due in large part, to the fact that gravity allows the jugular venous system to become the main outflow.  The collateral venous system, which is activated when we are upright, gives way to the larger jugular veins.  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1665206/

In normal people-- who do not have jugular venous malformations, or CCSVI-- this allows for effective flow while supine.  Why is this important?  Because it appears that this flow is essential for removal of waste from the brain.  Here's more from the U of R--