Eavesdropping on Nerve Cell Conversations to Probe Brain Function

Release Date:

Every second of every day, our five senses capture a vast amount of what is going on in our world. In a process scientists are still working to understand, billions of brain cells communicate with each other by exchanging tiny electrical pulses, each lasting just a few thousandths of a second. For many years, scientists have listened in on this chatter, usually recording the pulses from only one cell at a time.

Now, a team of scientists at Princeton University in New Jersey is one step closer to understanding how the brain works as a unit. Led by theoretical physicist William Bialek, Ph.D., and experimental physicist Michael Berry, Ph.D., the researchers combined new methods and new math to study "conversations" among nerve cells in the eyes of salamanders. Focusing on the cells that line the back of the eye and transmit visual signals to the brain, the scientists recorded pulses from 40 cells simultaneously as the living animal’s eye responded to movies taken from its natural environment.

Using mathematical models to sort through the patterns of pulses and silence, the team determined that nerve cells almost always talk to just one other cell at a time, as opposed to having group discussions. The researchers concluded that only after participating in many such "informed-pair conversations" did the cells decide what to do.

While a salamander's retina is far simpler than the human brain, the findings nonetheless open the door for understanding even larger nerve cell networks and brain functions.