One size does not fit all Oligodendrocytes are best known for their ability to myelinate brain neurons, thus increasing the speed of signal transmission. Marques et al. surveyed oligodendrocytes of developing mice and found unexpected heterogeneity. Transcriptional analysis identified 12 populations, ranging from precursors to mature oligodendrocytes. Transcriptional profiles diverged as the oligodendrocytes matured, building distinct populations. One population was responsive to motor learning, and another, with a different transcriptome, traveled along blood vessels. Science , this issue p. 1326

Oligodendrocyte heterogeneity in the mouse juvenile and adult central nervous system