Dan, Tobin, Kyle Kyburz, and undergraduate researcher Emi Kiyotake report on a photodegradable hydrogel for the co-culture of motor neurons and muscle cells. Confocal microscopy is used to erode three-dimensional channels allowing directed axon extension. The article currently appears in Biomacromolecules: Just Accepted Manuscripts. http://pubs.acs.org/doi/abs/10.1021/bm500731b