INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
ELECTRICAL ACTIVITY REGULATES PLEXIN A3-MEDIATED AXON PATHFINDING IN DEVELOPING ZEBRAFISH SPINAL MOTOR NEURONS
Autor/es:
PAOLA V. PLAZAS; NICHOLAS C. SPITZER
Lugar:
Rosario
Reunión:
Congreso; Latin American Zebrafish Network 2nd Annual Meeting; 2012
Resumen:
The role of electrical activity in axon guidance has been extensively studied in vitro. To better understand its role in the intact nervous system we imaged intracellular Ca2+ in zebrafish primary motor neurons (PMN) during axon pathfinding in vivo. We found that PMN generate specific patterns of Ca2+ spikes at different developmental stages. Spikes arose in the distal axon of PMN and were propagated to the cell body. Suppression of Ca2+ spiking activity in single PMN led to stereotyped errors but silencing all electrical activity had no effect on axon guidance, indicating that an activity-based competition rule regulates this process. This competition was not mediated by synaptic transmission.The guidance receptor PlexinA3 plays a major role in PMN axon pathfinding. Combination of PlexinA3 knock-down with suppression of Ca2+ activity in single PMN produced a synergistic increase in the incidence of pathfinding errors. However, expression of PlexinA3 transcripts was not regulated by activity.  Our results provide an in vivo demonstration of the intersection of spontaneous electrical activity with the PlexinA3 guidance molecule receptor in regulation of axon pathfinding.