News: Researchers have identified the crucial role of astrocytes in closing the period of brain plasticity that follows birth, that aids in the development of sensory and cognitive faculties.
Brain plasticity is a transient key period after birth in which the brain remodels the “wiring” of the neurons according to the external stimulations it receives (environment, interactions, etc.). The “closure” — of this period marks the stabilization of the neural circuits, associated with efficient information processing and normal cognitive development. Any problem with closing these periods results in neurodevelopmental disorders. Researchers are unaware of the cellular processes defining the critical-period timing.
Astrocytes are brain cells, which have long been considered only as mere support cells for neurons. Now researchers from Inserm, CNRS and Collège de France at the Center for Interdisciplinary Research in Biology demonstrated that astrocytes control critical-period closure in the mouse visual cortex.
They have uncovered an underlying pathway, which involves astrocytic regulation of the extracellular matrix, allowing interneuron maturation.
Unconventional astrocyte connexin signaling hinders the 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.
The study findings published have important implications for developing new strategies for reintroducing brain plasticity in adults, thereby promoting rehabilitation following brain lesions or neurodevelopmental disorders.
To Know More You May Refer To:
Ribot, J., Breton, R., Calvo, C., Moulard, J., Ezan, P., Zapata, J., Samama, K., Moreau, M., Bemelmans, A., Sabatet, V., Dingli, F., Loew, D., Milleret, C., Billuart, P., Dallérac, G., & Rouach, N. (2021). Astrocytes close the mouse critical period for visual plasticity. Science, 373(6550), 77-81. https://doi.org/10.1126/science.abf5273