Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 23: Cell Motility and Migration (in vitro and in vivo)

BP 23.2: Vortrag

Donnerstag, 29. März 2007, 14:30–14:45, H43

Origins and Limitations of Optical Neuron Guidance — •Daniel Koch, Timo Betz, Allen Ehrlicher, Björn Stuhrmann, Michael Gögler, and Josef Käs — Institute for Soft Matter Physics, University of Leipzig, Linnestr. 5, 04103 Leipzig, Germany

The growth cone, a highly motile sensory structure at the tip of an advancing neurite, plays a fundamental role in the wiring of neuronal connections during development, nerve regeneration, and in neuronal plasticity. The dynamics of the leading edge is governed by actin polymerization and can be described as a bistable stochastic process which means polymerization is either turned on or off. Furthermore, the direction taken by the growth cone is introduced by the orientation of the filopodia which are force sensitive actin filament bundled structures that emerge from the leading edge. In actively extending growth cones, a laser spot placed at the leading edge affects the direction taken by the growth cone. However, optical control is not achieved in non-extending growth cones with polymerization mostly turned off which sets a natural limit for optical neuron guidance. The analysis of optically induced turning events reveals that the applied optical forces lead to filopodia reorientation. We hypothesize that the filopodia are coupled back into the central region and in a lever arm like fashion change the extension of the leading edge.