BDNF and neuropathy: In this work, gLL systems were used to evaluate the viability and adhesion of glia upon different extracellular matrix (ECM) compounds of poly-L-lysine (PLL), laminin (LM), and collagen I (CL), as well as glia migration in response to dosage-dependent signaling from epidermal growth factor (EGF), brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF), which are key factors in neuropathies of the visual and peripheral NS.