title: Model of fasciculation and sorting in mixed populations of axons.
abstract: We extend a recently proposed model [Chaudhuri et al., Europhys. Lett. 87, 20003 (2009)] aiming to describe the formation of fascicles of axons during neural development. The growing axons are represented as paths of interacting directed random walkers in two spatial dimensions. To mimic turnover of axons, whole paths are removed and new walkers are injected with specified rates. In the simplest version of the model, we use strongly adhesive short-range inter-axon interactions that are identical for all pairs of axons. We generalize the model to adhesive interactions of finite strengths and to multiple types of axons with type-specific interactions. The dynamic steady state is characterized by the position-dependent distribution of fascicle size and fascicle composition. With distance in the direction of axon growth, the mean fascicle size and emergent time scales grow monotonically, while the degree of sorting of fascicles by axon type has a maximum at a finite distance. To understand the emergence of slow time scales, we develop an analytical framework to analyze the interaction between neighboring fascicles.
authors.affiliation: Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, D-01187 Dresden, Germany. d.chaudhuri@amolf.nl
authors.forename: Debasish
authors.initials: D
authors.lastname: Chaudhuri
authors.forename: Peter
authors.initials: P
authors.lastname: Borowski
authors.forename: Martin
authors.initials: M
authors.lastname: Zapotocky
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D051379:Mice; D008954:Models, Biological; D009010:Monte Carlo Method; D009830:Olfactory Bulb / Q000166:cytology; D011984:Sensory Receptor Cells / Q000166:cytology; D013997:Time Factors