In normal development, the progeny of ES cells differentiate into every cell type. The neurons are fully functional and have axons and dendrites that make functional chemical synapses.
Oligodendrocytes are capable of forming myelin.
Genetic manipulation of ES cells via gene targeting has opened up powerful strategies for addressing the role of genes in development, adult function and disease. Gottlieb, D.I. Neuronlike cells derived in culture from P19 embryonal carcinoma and embryonic stem cells. Culturing Nerve Cells. McDonald JW, Liu X-Z, Ou Y, et al. Transplanted embryonic stem cells integrate, differentiate and promote recovery in injured rat spinal cord.