Although the gray matter in the brain attracts the attention of many researchers, half of the brain actually consists of a connective tissue called white matter. A new study highlights some important signals that we need to pay more attention to these faded highways.

Gray matter consists primarily of nerve cell bodies that perform calculations responsible for our language, learning, cognition, sensations, and movements. White matter consists mainly of structures called axons, which are responsible for connecting brain cells to each other and to the rest of the body.

The Vanderbilt University research team behind the new study used functional magnetic resonance imaging (MRI) to observe changes in white matter as subjects performed tasks such as moving their fingers.

Currently, white matter signals are often ignored or discarded in fMRI scans because they are weaker and harder to see. To overcome this, study participants were asked to continue repeating their assigned actions to establish a trend and pattern that could be appropriately measured.

There was a significant increase in blood oxygen level-dependent (BOLD) signals in the white matter; This suggests that brain activity increases during tasks. Even though we don’t know exactly what’s going on yet, this is an important understanding.

“We don’t know what this means,” says biomedical engineer Curt Schilling. “We just know something is going on. There’s a really strong signal in the white matter.”

Increased BOLD signals in gray matter indicate increased blood flow and oxygenation to the brain. It could be the same for white matter cells: It could mean more oxygen is being used when the brain is working, or it could be related to gray matter activity in some way.

Because white matter controls communication, we need to better understand what’s going on here; When the connection is disrupted, many disorders can occur, from epilepsy to multiple sclerosis.

“The signal is changing,” Schilling says. “It changes differently in different white matter tracts and occurs in all white matter tracts, which is a unique finding.”

In future studies, these white matter signals can be examined in more detail, especially in relation to health problems such as Alzheimer’s disease. Researchers also want to investigate the biological causes of this activity.

The neglect of white matter activity is something researchers want to change in the future. The team behind the research says these signals are useful indicators of brain activity, not background noise. Source