Selective Silencing

A classic approach to deducing what role an individual part plays in a biological system is to remove it and see what changes. For example, researchers interested in the peripheral nervous system tried to genetically modify certain nerves to ‘switch off’ when a toxin, diphtheria toxin (DT), was introduced. But they found a problem: DT is small and can pass into the brain, meaning it affected brain cells as well. So they tried enlarging DT, preventing it squeezing into the brain. To test its efficacy, they used it in mice to silence a group of neurons (orange) that lie within a neuron bundle (green) close to fat. With these silenced, mice rapidly put on weight, but crucially didn’t change their eating behaviour as their brain remained unaffected. Not only does this reveal information about the neurobiology of obesity, it also clears a path to study neuron function throughout the body.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image by Roksana Pirzgalska, Instituto Gulbenkian de Ciência
• Instituto Gulbenkian de Ciência, Oeiras, Portugal
• Image copyright held by original authors
• Research published in Nature Communications, April 2017