 These studies investigated how this programmed cell death, apoptosis, occurred in such a tremendous scale.Additionally, he studied processes such as the prerequisites for and consequences of axon myelination, and the interactions of various signaling molecules such as thyroid-hormone and retinoic acid within the formation of glial cells including oligodendrocytes.Early in his time at Stanford, Barres discovered the importance of glial cells in the formation, development, maturation, and regeneration of neurons.