Regulation of developing myelin sheath elongation by oligodendrocyte calcium transients in vivo

Abstract

How action potentials regulate myelination by oligodendrocytes is uncertain. We show that neuronal activity raises [Ca2+](i) in developing oligodendrocytes in vivo and that myelin sheath elongation is promoted by a high frequency of [Ca2+](i) transients and prevented by [Ca2+](i) buffering. Sheath elongation occurs similar to 1 h after [Ca2+](i) elevation. Sheath shortening is associated with a low frequency of [Ca2+](i) transients but with longer duration [Ca2+](i) bursts. Thus, [Ca2+](i) controls myelin sheath development.

How action potentials regulate myelination by oligodendrocytes is uncertain. We show that neuronal activity raises [Ca2+](i) in developing oligodendrocytes in vivo and that myelin sheath elongation is promoted by a high frequency of [Ca2+](i) transients and prevented by [Ca2+](i) buffering. Sheath elongation occurs similar to 1 h after [Ca2+](i) elevation. Sheath shortening is associated with a low frequency of [Ca2+](i) transients but with longer duration [Ca2+](i) bursts. Thus, [Ca2+](i) controls myelin sheath development.