Coordinated Cuts

Two gardeners communicate constantly as they prune a hedge to achieve topiary perfection. A study has identified a pair of molecular trimmers doing a similar job in the developing brain. Two types of glial cells – cells in the brain that support neurons – cooperate to prune brain connections in response to particular experiences as the brain wiring takes shape. One type (ensheathing glia, pictured, left in the juvenile fruit fly brain) produces serotonin, which signals the second type (astrocyte-like glia, right) to produce an enzyme that remodels the environment around neurons, allowing glial cells to infiltrate and prune at joints (synapses) between neurons. Activating this pathway re-activated plasticity even in older flies. Comparable pathways are equally important in humans, and excessive, insufficient, or off-target pruning is linked to a range of mental and neurological conditions, so understanding how glial serotonin controls this may open a new entry point for treatment approaches.

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 on Bluesky by Vanessa Miller. Research by Vanessa Kay Miller & Kendal Broadie
• Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Research published in PLOS Biology, December 2025