Physics: Scientists Disprove Century-Old Assumption About the Brain’s Neurons

For a century, scientists have relied on a fundamental assumption about the brain’s neurons. New research shows it’s wrong and could revolutionize the way we approach treatments for degenerative diseases. NASA

For more than 100 years, physicists have relied on a “neuron computational scheme” that assumed the neurons within our brains are individual excitable elements. In a new paper published in the journal Scientific Reports, a team of physicists provides evidence that the traditional scheme has been wrong—each neuron functions as a collection of excitable units, not a single centralized one. The discovery could revolutionize the way we approach treatments for degenerative diseases.

Neurons themselves are the basic building blocks that make up the computational abilities of our brain. Scientists have assumed that they work by receiving incoming electrical signals, and then once they’ve reached a certain threshold by generating a spike—a quick electrical pulse. 

In a series of lab experiments on neuron cell cultures, researchers from Bar-Ilan University and Tel Aviv University in Israel discovered that not only does each neuron work as a collective, each component of that collective—each excitable element—is sensitive to the direction from which the electrical signals come. A weak signal from the left and a weak signal from the right won’t add up to enough to cause a spike; meanwhile, a strong signal from the left generates a different kind of spike than does a strong signal from the right.

If the subject itself sounds tiny and obscure, its implications are enormous. Neurons in the brain that can’t tell the difference between ‘right’ and ‘left’ are signs of further distortions elsewhere in the body, and could point us to the origins of a number of major diseases. The researchers believe their work is the first to present both the idea and the results.

“As a result of these findings, scientists may now be able to more effectively study degenerative disease, such as Parkinson’s and Alzheimer’s diseases, as well as other neurological-induced diseases like strokes,” corresponding author Ido Kanter, a physics professor at Bar-Ilan University, explained to Newsweek over email. “This discovery could advance medical research by leaps and bounds toward the discovery of new treatments and new types of cures.”

According to Kanter, the technology to do what he and his colleagues have done has existed for several decades; the delay was because the assumption about the nature of the brain’s neurons was simply that deeply rooted in the scientific community. With future research, Kanter said, he has his ambitions set as high as potentially introducing a hierarchy system, separating neurons into different classifications.