Microglia:  Credit: Wai T. Wong, National Eye Institute, NIH

Everyone knows about bone cartilage, but fewer people are aware of “brain cartilage.” The cartilage-like substance is composed of long chains of sugar molecules attached to a protein matrix, smeared over the surface of many types of brain cells.   When examined under a microscope the substance looks like a wet fishnet clinging to neurons, inspiring the name “perineuronal nets.”  Like a fishnet, perineuronal nets trap neurons and their synapses, preventing them from sprouting and making new connections.  Brain cartilage stabilizes neural networks, but this also makes modifying them more difficult.  While many study the internal workings of neurons, this coating on the outside provides answers to some of the most puzzling questions about the brain:  Why is it so hard to stop drinking after becoming dependent on alcohol?  Why do young brains absorb new information so easily and heal more rapidly after injury?  Why are fearful memories that torment people with PTSD so difficult to forget?  Perineuronal nets provide answers, and according to new research from neuroscientist Arkady Khoutorsky and his colleagues at McGill University, perineuronal nets are also why pain develops and persists so long after nerve injury.

Read the story in Quanta Magazine:  https://www.quantamagazine.org/neuronal-scaffolding-plays-unexpected-role-in-chronic-pain-20220728/