Schwann cells fail to develop in mouse embryos lacking functional ErbB3 neuregulin receptors, and most sensory and motor neurons subsequently die in these mice. As ErbB3 acts cell autonomously in Schwann cell development but not in neuronal survival, neurons may depend on Schwann cells for survival.
Davies, A. M. (1998, January 1). Neuronal survival: Early dependence on Schwann cells. Current Biology. Cell Press. https://doi.org/10.1016/s0960-9822(98)70009-0