Good Sleep Improves Brain Cell Production

Researchers from the University of Wisconsin-Madison have discovered that the sleeping brain generates cells, which repair damaged nerve cell insulations

The research was spearheaded by Dr. Chiara Cirelli, Professor of Psychiatry at the University of Wisconsin School of Medicine and Public Health. Dr Cirelli along with colleagues found that various diseases like multiple sclerosis harm the nerve cells and sleeping helps in repairing the insulation sheath called myelin, which surround these nerve cells.

The experimenters studied the mice brain and found that various genes involved in generating cells and fixing the myelin sheath, which is wrapped around the neuron or nerve cell's axon, turn active during sleep. On the other hand, genes associated with the death of these cells are produced during wakeful hours.

 "It is an intriguing finding, so much so that we almost didn't believe it at first," said Cirelli. "It's very puzzling because myelin is known to grow very slowly and myelin cells typically turn over during a period of weeks and months."

Professor Cirelli explained that the idea for this experiment is about a decade old, she had collaborated with Dr. Giulio Tononi in 2004 and found hundreds of genes that were active during sleep but were not so during wakeful hours. But due to lack of proper equipment they could not isolates the particular genes that got active in the brain tissues.

But with modern techniques like the translating ribosome affinity purification (TRAP) they were able to look at the genes which activate myelin cells.

The genes in glial cells, precursors to myelin cells were observed. These cells supply oxygen and nutrients to the neurons, remove dead neurons, destroy the pathogens and also insulate one neuron from another.

The researchers found that cells called oligodendrocyte precursor cells (OPCs) double during sleep especially during the rapid eye movement phase (REM sleep). Whereas genes associated with cell death and stress were found to turn on in the wakeful hours.

 "It's basic research, so we shouldn't read too much into it," Cirelli cautions, "but it is quite a surprising finding."

This research unveils the effect of sleep related to damage or repair of the brain.