Fear Circuits

Humans are born with certain innate fears – loud noises, heights, or the dark perhaps. But, in some instances, a person can learn to overcome them. And, scientists have recently found the brain regions involved in such fear suppression – in mice at least. These areas include the highlighted portions of the cerebral cortex (towards the top of the brain slice pictured) and their corresponding projections to the ventrolateral geniculate nucleus (the matching colours on the inner region). When mice are repeatedly exposed to an overhead expanding shadow – mimicking an advancing predator – with no actual threat, they eventually learn to stop running away. When researchers suppressed the activity of the highlighted cortical neurons, however, the mice failed to suppress their innate fear. Importantly, identifying the equivalent fear suppression networks in humans might provide clues as to how to override exacerbated fear responses in patients with anxieties, phobias and PTSD.

Written by Ruth Williams

Ruth Williams

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Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

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• Image from the Sainsbury Wellcome Centre, posted on EurekAlert! From work by Sara Mederos and colleagues
• Sainsbury Wellcome Centre, University College London, London, UK
• Image usage restrictions: Use with credit, which equates to a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Research published in Science, February 2025