Erin Craig (Physics)
During neural development, a structure at the tip of a growing axon called the growth cone detects extrinsic guidance cues in order to advance the axon to the correct synaptic target. Several experimental studies have shown that near infrared (NIR) lasers can change the direction of growth cone motility and axonal outgrowth, with the potential to be used for neural repair once the mechanism for optical guidance of growth cone motility is better understood. Here, we develop a computational model of the growth cone turning mechanism in response to a NIR laser, based on the hypothesis that the laser induces asymmetric growth of an intracellular network of filaments called f-actin. To test our hypothesis, we developed a computational framework in MATLAB to simulate growth cone motility in response to a focused laser beam applied to one side of the growth cone. Our simulations predict changes in the shape of the growth cone that precede growth cone turning toward the site of the laser. The framework we established for predicting growth cone motility for different laser placement strategies can be used as a tool for planning experimental tests. Detailed understanding of NIR laser guidance of growth cones could contribute to the development of minimally invasive techniques for neural repair.
Keywords: Biophysics, Neuroscience, Growth Cones