Deconstructing Brain Wiring, One Neuron at a Time

Researchers have long said they won’t be able to understand the brain until they can put together a “wiring diagram” – a map of how billions of neurons are interconnected. Now, researchers at the Salk Institute for Biological Studies have jumped what many believe to be a major hurdle to preparing that chart: identifying all of the connections to a single neuron.

In the March 1 issue of the journal Neuron, the researchers describe how they modified the deadly rabies virus, turning it into a tool that can cross the synaptic space of a targeted nerve cell just once to identify all the neurons to which it is directly connected.

“We’ve wanted to do this for a very long time and finally found a way to make it possible,” says the study’s senior author, Edward M. Callaway, Ph.D., a professor in the Systems Neurobiology Laboratories. “It will offer us an unprecedented view of the brain.”