IMBICE   05372
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA CELULAR
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Inactivation of axonal EphA4 stimulates axon growth of nasal retinal ganglion cells
Autor/es:
DI NAPOLI, JENNIFER; FIORE, LUCIANO; ALONSO C; RODRIGUEZ CELIN, AJ; PASQUALE E.B.; CARRI, NÉSTOR GABRIEL; SCICOLONE, GABRIEL
Lugar:
New York
Reunión:
Congreso; SfN; 2010
Institución organizadora:
SfN
Resumen:
Retinotopic
projection onto the tectum constitutes the most detailed studied model of
topographic mapping and Ephs and their ligands, the ephrins, constitute the
main molecular system involved in this process. Ephrin-As, expressed in an
increasing rostrocaudal gradient in the tectum, repel temporal retinal ganglion
cells (RGCs)
from the
caudal tectum. Using retinal cultures and producing in vivo EphA3
misexpression, we demonstrated that EphA3, expressed in a decreasing
rostrocaudal gradient in the tectum, stimulates the nasal axon growth toward
the caudal tectum. Therefore, we proposed a general model for topographic
mapping in which the same
molecules
functioning as membrane-bound ligands and receptors label both the topographic
addresses onto the target and the relative sensitivity of the projections
according to their topographic origin. However, it is not known which
molecule/s mediates the EphA3-mediated effect on RGCs axons. We postulated that
EphA4 activation decreases axon growth and that tectal EphA3 increases axon
growth by reducing EphA4 activation through competing with axonal EphA4 for
axonal ephrin-As binding.