Physics professor explains nerve signals

Only one percent of neurons in the brain send the majority of nerve signals, according to recent IU studies. 
 
Physics professor John Beggs explained why this occurs and how the distribution might actually make an individual’s brain more efficient.

The discussion took place at 6:30 p.m. Tuesday at Finch’s Brasserie on Kirkwood, and was part of the 2013 Themester, Connectedness: Networks in a Complex World.

Marta Schocket, graduate student and Bloomington Science Café event organizer, said Beggs is a great match for the Themester’s theme of networks and
connectedness.

“He studies neuroscience from an information theory and physics perspective,” Schocket said.    

Beggs said each neuron in the cortex makes and receives about 7,000 synapses with other cortical neurons. In this respect, connections are distributed very democratically, Beggs said.

Dr. Beggs’ lab uses microelectrode arrays to eavesdrop on how networks of up to 500 neurons send signals to each other. Beggs compared these neurons and synapses to “clown cars” due to how tightly packed they are in our brain.

Beggs and his team have tested their research on animal brains as well as human brains.

“What we’ve decided to do is get as many wires as close together as possible and take a thin slice of brain,” Beggs said. “Then we put it down on an electrode ray, and you would see lots of wires. This system allows us to record for brain cells.”

To Beggs’ surprise, they found only a small percentage of neurons do most of the “talking.” These neurons are called “hub neurons.”

Beggs and many other physicists and students have been working on this research since 2006.

“The question was, how does information flow in networks of the brain cells?” Beggs said. “The approach was, hey, let’s record as many brain cells as we can.

“What we found was that there are these neurons called hubs that have many more connections than the average neuron. It might make the network more
efficient.”

Beggs and his team of researchers are currently continuing to work on the project and hope to make more advancements in the future, he said. 

“It’s hard to come up with any firm conclusions,” Beggs said.

Schocket and Ellen Herbert organized Tuesday’s event, which was sponsored by Bloomington Science Café. Bloomington Science Café is part of a grassroots, international movement to bring scientists and the public together in informal settings to discuss scientific research and make it more accessible to a general
audience.

This event was also sponsored by the College of Arts and Sciences, Maurer School of Law, Department of Biology, School of Public and Environmental Affairs, and the Integrative Program in the Environment.

“We want to get the community involved,” Schocket said. “People are really interested about finding out and learning about science.”

Follow reporter Torie Schumacher on Twitter @shoe_torie.