Axonal transport properties of diverse cargoes revealed by informatic analysis of high resolution movies

MATIAS ALLOATI; VALENTINA LACOVICH; MARIA GABRIELA OTERO; SONIA ESPÍNDOLA; VICTORIO POZO DEVOTO; ELENA AVALE; LUCIANA BRUNO; TOMAS FALZONE

Workshop; Workshop Internacional Programa Raíces (MINCyT):"La matemática como herramienta para entender la biología / la biología como fuente de problemas matemáticos",; 2015

The movement of particles along polarized neurons involves many players: microtubule tracks that are stabilized by associated proteins, molecular motors directing the movement along these tracks, and cargoes transported, associated directly or indirectly with motors. The extreme length of axons in neurons requires a complex axonal transport system that ensures neuronal survival through the proper distribution of cargoes to distant regions of the cell. Due to the many players involved in this complex system, is hard to obtain clean interpretation of results obtained from axonal transport experiments. To perform deep analysis of the movement properties of cargoes from different origins, we generated movies from axons and processed them with informatic scripts. We analyze two very different cargoes: a fast moving vesicle (APP tagged vesicles) and a cytosolic moving protein complex (the proteasome). We developed informatic tools to track individual particles and determined the axonal transport properties of both cargoes. We revealed that proteasomes move with at least three different motion regimes and characterized diffusion properties, confined movements and motor-dependent transport for this complex. In addition, we characterized the axonal transport abnormalities of APP vesicles when microtubule tracks are impaired by the exchange of the expression of the isoforms of a microtubule associated protein (tau). Taken together, our results show a useful informatic processing approach to analyze and comprehend the contribution of different players in the movement properties behind axonal transport.