Gianluca Gallo

• 
  Cytoskeletal basis of axon collateral branching: Insights from Monte Carlo simulations
  Gianluca Gallo

  The formation of a functional nervous system requires the establishment of proper patterns of synaptic connectivity between neurons. Each neuron generates a single axon, but often makes synapses on 100s-1000s of other neurons in disparate parts of the nervous system. The ability of a single axon to generate such complex patterns of connectivity is due to the branching of the axon. Neuronal morphogenesis is dependent on the interactions between the two major components of the cytoskeleton; actin filaments and microtubules. Branches are initiated as actin filament based filopodial protrusions from the main axon shaft, which subsequently mature into branches containing actin filaments and microtubules. This presentation will detail a Monte Carlo simulation of the basic cytoskeletal events underlying the formation of axon branches. The simulation receives empirically derived input values related to aspects of the dynamics of the actin and microtubule cytoskeleton, and returns outputs in the same metric as empirically determined measurement of branch formation. The simulation thus allows direct analysis between empirically derived variables and the final output of the system (i.e., branch formation). The simulation faithfully reproduces the effects of branch inducing factors (e.g., NGF) and suggests new venues of empirical investigation.