This image is of a cell culture in vitro, which means that the cell culture was observed in a controlled environment, like a test tube or petri dish. Here, oligodendrocytes, the glial cells of the central nervous system, are producing myelin that is wrapped around the axon of a neuron. Myelin is a lipid membrane that is produced by glial cells (Schwann cells for the peripheral nervous system and oligodendrocytes for the central nervous system) that protect neurons and allow electrical impulses to travel quickly.

In M.S., or multiple sclerosis, the disease attacks and destroys oligodendrocytes and myelin, which are responsible for transporting signals within the brain. Hence, studying the growth of oligodendrocytes could lead to the treatment of M.S.

Y. He, J. Dupree, J. Wang, J. Sandoval, J. Li, H. Liu, Y. Shi, K. A. Nave, P. Casaccia-Bonnefil. The Transcription Factor Yin Yang 1 Is Essential for Oligodendrocyte Progenitor Differentiation. Neuron, 2007, 55 (2), 217–230. DOI: https://doi.org/10.1016/j.neuron.2007.06.029.