Astrocytes close the mouse critical period for visual plasticity
Jérôme Ribot, Rachel Breton, Charles‐Félix Calvo, Julien Moulard, Pascal Ezan, Jonathan Zapata, Kevin Samama, Matthieu X. Moreau, Alexis‐Pierre Bemelmans, Valentin Sabatet, Florent Dingli, Damarys Loew, Chantal Milleret, Pierre Billuart, Glenn Dallérac, Nathalie Rouach
Abstract
Brain postnatal development is characterized by critical periods of experience-dependent remodeling of neuronal circuits. Failure to end these periods results in neurodevelopmental disorders. The cellular processes defining critical-period timing remain unclear. Here, we show that in the mouse visual cortex, astrocytes control critical-period closure. We uncover the underlying pathway, which involves astrocytic regulation of the extracellular matrix, allowing interneuron maturation. Unconventional astrocyte connexin signaling hinders expression of extracellular matrix-degrading enzyme matrix metalloproteinase 9 (MMP9) through RhoA-guanosine triphosphatase activation. Thus, astrocytes not only influence the activity of single synapses but also are key elements in the experience-dependent wiring of brain circuits.