Oligodendrocytes lay down multiple layers of myelin around axons, increasing signal speed up to 50-fold. Recent work suggests that neural impulses can stimulate myelination.
Image: Alan Hoofring
In Brief
- Neurons make up only 15 percent of our brain cells. Glial cells make up the rest.
- Glial cells can control communication between neurons and play a central role in learning, but for years they were dismissed as mere putty.
- Most neurological and some psychological disorders involve glia, so new therapies are targeting these cells.
Sitting in a darkened lab at the National Institutes of Health in 1999, my colleague Beth Stevens and I prepared to send a mild electric current through fetal mouse neurons in a cell culture. We were using a new microscope technique that would let us see electrical activity as a bright fluorescence emitted from a dye we had added to the culture, and we were hoping to find out if another kind of cell common in the nervous system would react in some way—Schwann cells, odd-looking cells that fabricate insulation around neurons. We didn’t really expect them to; Schwann cells cannot communicate electrically. I flipped the switch. The neurons immediately glowed. But then the Schwann cells began to glow as well. It was as if they were talking back.
The most mysterious substance on earth is the stuff between your ears, and much of the intrigue exists because many long-held beliefs about how the brain works have turned out to be wrong. Like medieval astronomers who were shocked to learn that the earth is not the center of the universe, neuroscientists today are facing a similar revelation about neurons.
This article was originally published with the title The Hidden Brain.
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4 Comments
Add CommentA link would vastly improve your snarky comment.
Reply | Report Abuse | Link to thisThanks.
Theories like neural correlates of consciousness based on brain biology and its neuronal circuitry only partially explains phenomenology of experience .Physical states of brain may correspond to this,and how or why such states should give qualia or the feeling associated with experience is not explained by such physical theories based on reductionist approaches that take into account only brain biology in terms of neuronal circuitry.
Reply | Report Abuse | Link to thisGlia material may help to explain mind and its subjective ontology better
SURESHKUMAR.S,SCIENTIST AND ADVISER,NIIST[CSIR],INDIA
My impression is that once a sensory input has been received then the bulk of the work begins in the brain. As Dr Suresh. is suggesting we still have a long way to go on the road to understanding the mechanisms employed by the brain in its control functions. Why do some memories last for a lifetime, but most importantly HOW? How are old memories brought to the surface of consciousness again? Could it be that the very materials that cause problems in aging could have a useful function in managing the timely flow of information into human consciousness, and in suppressing distracting turbulent recall? This would make for some interesting research.
Reply | Report Abuse | Link to thisTo suresh10in: Why should glia explain "mind and its subjective ontology" better than "brain biology and its neuronal circuitry"? Glia are biological, too!
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