This is a dendrite, the branch-like structure of a single neuron in the brain. The bright object from the top is a pipette attached to a dendrite in the brain of a mouse. The pipette allows researchers to measure electrical activity, such as a dendritic spike, the bright spot in the middle of the image. Credit: Spencer Smith
Dendrites, the branch-like projections of neurons, were once thought to be passive wiring in the brain. But now researchers at the University of North Carolina at Chapel Hill have shown that these dendrites do more than relay information from one neuron to the next. They actively process information, multiplying the brain's computing power.
"Suddenly, it's as if the processing power of the brain is much greater than we had originally thought," said Spencer Smith, PhD, an assistant professor in the UNC School of Medicine.
His team's findings, published October 27 in the journal Nature, could change the way scientists think about long-standing scientific models of how neural circuitry functions in the brain, while also helping researchers better understand neurological disorders.
"Imagine you're reverse engineering a piece of alien technology, and what you thought was simple wiring turns out to be transistors that compute information," Smith said. "That's what this finding is like. The implications are exciting to think about."
"All the data pointed to the same conclusion," Smith said. "The dendrites are not passive integrators of sensory-driven input; they seem to be a computational unit as well."
A network of pyramidal cells in the cerebral cortex. These neurons have been simulated using a computer program which captures the beautiful dendritic architecture of real pyramidal cells. These dendrites have now been shown to carry out sophisticated computations on their inputs. Credit: UCL