How the brain thinks is something less of a mystery today, thanks to the work of two University scientists.
Some cells in the brain, called glial cells, were previously thought to have little function other than aiding the neurons that make up the bulk of the brain’s network. University researchers have forced physiologists to rethink this assumption.
The research of physiology professor Dr. Eric Newman and assistant professor Kathleen Zahs, published as the cover story in Thursday’s issue of Science magazine, shows that glial cells do indeed communicate with each other. The research may be helpful in understanding the function of the cells, which play a role in diseases, such as Parkinson’s disease or multiple sclerosis — conditions that have frustrated scientists for years.
“This opens up a whole new range of thinking about the role of glial cells,” said Head of the Physiology Department Dr. Robert Miller.
Previously, glial cells — named for the German word for glue — were thought to support the nerve cells that do the major communication in the brain.
“The nerve cells have traditionally been thought of as the only cells that take part in the information processing,” Newman said.
Although glial cells communicate millions of times slower than their counterparts, the discovery shows that glial cells may influence the behavior of nerve cells. Newman and Zahs will explore that possibility within the next year or so.
The influence might prove key to understanding brain disorders, such as Parkinson’s. The disease occurs when nerve cells die, but the mechanics behind the death of the neurons is a mystery. Newman and Zahs are hopeful that the glial cells could produce messages that might save the neurons and possibly treat Parkinson’s.
The glial cells may also play a part in higher brain functions, such as consciousness.
“If the glial cells were capable of operating within circuits of their own, then it is quite possible that phenomena like mood changes or consciousness may in fact reflect glial cell activity as well as nerve cell activity,” Miller said. “There is the famous work that showed that Albert Einstein’s brain seemed to differ from the brains of other people by having more glial cells. So maybe when we get smart, we get smart because of what our glial cells do, whereas we’ve previously thought it must be the neurons doing something.”
Newman and Zahs used an intact rat retina in their experiments because the glial cells in a retina are easy to isolate. Researchers consider the retina to be a part of the brain. The researchers stimulated the cells using calcium waves, and with a special fluorescent dye they were able to see the waves spreading from one glial cell to the next.
The research took more than a year to complete.
“(Newman’s research) is a pretty big deal,” said Dr. Bruce Ransom, chairman of the neuroscience department at the University of Washington in Seattle and editor of the glial-cell research journal Glia. “The scientific community, overall, is very impressed by this work,” Ransom said.
Prior research indicated that glial cells might have been involved in some kind of communication, but most other researchers worked with cultured brain cells. Cultured cells are grown in the lab, rather than taken directly from an animal.
“Cultured brain cells can behave very differently than the cells do in real life in the brain, so we wanted to look at relatively intact tissue,” Zahs said.