Pain Pathway

This group of neurons (green) within a subsection of the brain's thalamus are a newly discovered part of the circuitry that links the physical sensation of pain to the emotional response. It's the emotional aspect of pain – the distress it causes – that teaches an animal to avoid potentially painful situations. Indeed, when carefully targeted genetic techniques were used to deactivate this particular group of neurons in mice, the animals could still sense the pain of heat or pressure but didn't learn to avoid the source of the stimulus. By contrast, when these neurons were artificially activated, the mice exhibited distress and avoidance behaviours even in the absence of actual pain stimuli. The identification of this emotional pain pathway offers new targets for developing different forms of pain medication that might be especially useful for people with increased sensitivity to pain or with chronic and distressing pain disorders.

Written by Ruth Williams

Ruth Williams

Writer

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

Website

• Image from work by Sukjae J. Kang and colleagues
• Peptide Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
• Image copyright held by the original authors
• Research published in Proceedings of the National Academy of Science (PNAS), July 2025