Satellite glial cells represent a population of developmentally arrested Schwann cells

Satellite glial cells (SGCs) are glial cells in the peripheral nervous system that form sheaths around the neuronal cell body. This unique arrangement of SGCs allows it to exert a highly regulated control over the neuronal microenvironment. Not much is known about the origin of SGCs. In this study, we examine the development of SGCs. We show that rat SGCs develop postnatally and these cells express a number of markers associated with Schwann cell precursors, in particular cadherin-19 (CDH19) even in adult DRGs. We developed a method for the purification of SGCs and showed that they are transcriptionally and morphologically very similar to adult rat Schwann cells (SCs). Finally, we demonstrate that purified SGCs are capable of myelinating embryonic axons when cocultured with those axons. Based on these observations we hypothesize that SGCs represent a population of cells in the SC lineage, whose further differentiation appears to be arrested through contact with DRG neuronal soma.