Controlling Growth Cone Behavior through Substrate Patterning

Throughout the process of development, billions of neuronal axons are responsible for navigating through the nervous system and synapsing onto their appropriate targets. To establish their individual paths, neurons are guided by a complex and dynamic map of biochemical, topographic, and mechanical signals. At the tip of each neurite lies the growth cone – a dynamic structure responsible for interpreting extracellular cues and steering neuronal growth in the appropriate direction. Growth cones in vivo exhibit various morphologies and behavioral changes, though the underlying mechanisms of these changes remain widely unknown. Through the use of substrate patterning techniques, we examined the relationship between growth cone morphology and behavior with the purpose of optimizing guidance in engineered regenerative systems. We investigated multiple substrate patterning techniques in order to achieve easily observable manipulations to growth cone morphology. We found that common micro-contact printing and microfluidic techniques are poor at creating isolated regions of overlapping biochemical cues. We also found that established protein patterning methods for soft substrates