RhoA regulates oligodendrocyte differentiation and myelination by orchestrating cortical and membrane tension.

Timely differentiation and myelin formation by oligodendrocytes are essential for the physiological functioning of the central nervous system (CNS). While the Rho GTPase RhoA has been hinted as a negative regulator of myelin sheath formation, the precise in vivo mechanisms have remained elusive. Here we show that RhoA controls the timing and progression of myelination by oligodendrocytes through a fine-tuned balance between cortical tension, membrane tension and cell shape.

Evolvability of the actin cytoskeleton in oligodendrocytes during central nervous system development and aging.

The organization of actin filaments into a wide range of subcellular structures is a defining feature of cell shape and dynamics, important for tissue development and homeostasis. Nervous system function requires morphological and functional plasticity of neurons and glial cells, which is largely determined by the dynamic reorganization of the actin cytoskeleton in response to intrinsic and extracellular signals. Oligodendrocytes are specialized glia that extend multiple actin-based protrusions to form the multilayered myelin membrane that spirally wraps around axons, increasing conduction speed and promoting long-term axonal integrity.