Dendritic Spike
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. © Spencer Smith

‘Mini-neural computer’ discovered in brain

Researchers have shown that dendrites are able to process information, multiplying the brain’s computing power. Dendrites, the branch-like projections of neurons, were once thought to be passive wiring in the brain and simply relay information.

The discovery, which was part-funded by the European Research Council, 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.

Spencer Smith, PhD, an assistant professor in the University of North Carolina School of Medicine, explained: “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. That’s what this finding is like. The implications are exciting to think about.

“Suddenly, it’s as if the processing power of the brain is much greater than we had originally thought,” Smith added.

Axons are where neurons conventionally generate electrical spikes, but many of the same molecules that support axonal spikes are also present in the dendrites. Previous research using dissected brain tissue had demonstrated that dendrites can use those molecules to generate electrical spikes themselves, but it was unclear whether normal brain activity involved those dendritic spikes. Following investigations, Smith and his team found dendrites to act effectively as mini-neural computers, actively processing neuronal input signals themselves.

The findings are published in the journal Nature.