Barres's research focused on using techniques such as immunopanning, immunohistochemistry, tissue culturing, and patch clamping to: 1) understand the cell-to-cell interactions in the developmental regulation of nodes of Ranvier and myelin sheaths; 2) determine to what extent glial cells play a role in synapse formation and function of synapses; 3) identify the signals that promote retinal ganglia growth and survival, and how such knowledge of these signals could be regenerated post-trauma; 4) identify the functions and developmental mechanisms of gray matter astrocytes. In these objectives, his lab discovered a number of novel glial signals for the induction of myelination, axonal sodium channel clustering, and synapse formation processes. Additionally, his lab characterized these processes and the exact identity of these novel signals.