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EphA5 and ephrin-A2 expression during optic nerve regeneration: a 'two-edged sword'
Citation
Symonds, ACE and King, CE and Bartlett, CA and Sauve, Y and Lund, RD and Beazley, LD and Dunlop, SA and Rodger, J, EphA5 and ephrin-A2 expression during optic nerve regeneration: a 'two-edged sword', European Journal of Neuroscience, 25, (3) pp. 744-752. ISSN 0953-816X (2007) [Refereed Article]
Copyright Statement
Copyright 2007 The Authors
DOI: doi:10.1111/j.1460-9568.2007.05321.x
Abstract
During development, gradients of EphA receptors (nasal(low)-temporal(high)) and their ligands ephrin-As (rostral(low)-caudal(high)) are involved in establishing topography between retinal ganglion cells (RGCs) and the superior colliculus (SC). EphA5-expressing RGC axons are repulsed by ephrin-A2-expressing SC neurones. In adult rats RGCs maintain graded EphA5 expression but ephrin-A2 expression is down-regulated in the SC to a weak gradient. At 1 month after optic nerve transection, EphA5 expression is reduced in the few remaining RGCs and is no longer graded; by contrast, SC ephrin-A2 is up-regulated to a rostral(low)-caudal(high) gradient. Here we examined expression in adult rat 1 month after bridging the retina and SC with a peripheral nerve graft, a procedure that enhances RGC survival and permits RGC axon regeneration. Double labelling with cell markers revealed preservation of a nasal(low)-temporal(high) EphA5 gradient in RGCs and establishment of a rostral(low)-caudal(high) ephrin-A2 gradient within neurones of the SC. The results suggest a potential for guidance cues to restore the topography of RGC axons in the SC. However, high ephrin-A2 levels were also found in astrocytes surrounding the peripheral nerve graft insertion site. The repulsive ephrin-A2 environment offers at least a partial explanation for the observation that only a limited number of RGC axons can exit the graft to enter target central nervous system tissue.
Item Details
Item Type: | Refereed Article |
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Keywords: | Eph, ephrin, optic nerve, regeneration |
Research Division: | Biomedical and Clinical Sciences |
Research Group: | Neurosciences |
Research Field: | Neurology and neuromuscular diseases |
Objective Division: | Health |
Objective Group: | Clinical health |
Objective Field: | Clinical health not elsewhere classified |
UTAS Author: | King, CE (Dr Carolyn King) |
ID Code: | 99039 |
Year Published: | 2007 |
Web of Science® Times Cited: | 21 |
Deposited By: | Health Sciences B |
Deposited On: | 2015-03-11 |
Last Modified: | 2015-04-15 |
Downloads: | 0 |
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