Researchers at Vanderbilt University have found previously undetected signals emanating from the human brain’s white matter, opening new pathways for discoveries in brain function and, potentially, into novel treatments for illnesses such as schizophrenia.

The brain holds gray matter and white matter in roughly equal proportions. Gray matter is made up of nerve cells that receive, process, and send information; white matter is the connections among nerve cells that carry those messages. 

Science knows much more about gray matter than white matter, partly because gray matter sends stronger signals. White matter’s signals can be hard to tell apart from simple static or background noise caused by the brain’s electrical activity.

Many studies of the brain have ignored white matter completely, assuming it is largely inert and that all meaningful activity happens in the brain cells themselves.

The Vanderbilt team has been using functional magnetic resonance imaging (fMRI) to detect specific signals within white matter that, thanks to their work, are now thought to be a key to brain activity.

To detect and record the signals, the scientists asked test volunteers to undergo simple activities, such as wiggling their fingers, while an fMRI machine scanned their brains.

What the scientists saw startled them: when the volunteers wiggled their fingers or performed some similarly simple task, white matter lit up throughout the brain, not just in the areas carrying messages about finger-wiggling.

“We don’t know what this means,” Vanderbilt professor of radiology Kurt Schilling said in a university press announcement. “We just know that something is happening. For 25 or 30 years, we’ve neglected the other half of the brain.”

“The signal is changing,” he added. “It’s changing differently in different white matter pathways and it’s in all white matter pathways, which is a unique finding.”

TRENDPOST: Epilepsy, multiple sclerosis, schizophrenia, and several other brain disorders arise because connections among nerve cells are disrupted. Vanderbilt’s finding creates an entirely new way to investigate causes and treatments for a range of brain-based illnesses.