Dynamic alterations of retinal EphA5 expression in retinocollicular map plasticity
Autor: | Qi Cheng, Sarah L. Pallas, Mark David Graves |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
0301 basic medicine
Retinal Ganglion Cells Superior Colliculi Receptor expression Plasticity Biology Retina Article 03 medical and health sciences Cellular and Molecular Neuroscience chemistry.chemical_compound 0302 clinical medicine Developmental Neuroscience Cricetinae medicine Animals Visual Pathways RNA Messenger skin and connective tissue diseases 030304 developmental biology 0303 health sciences Neuronal Plasticity Superior colliculus Receptor EphA5 Retinal Ligand (biochemistry) Expression (mathematics) Axons 030104 developmental biology medicine.anatomical_structure chemistry Models Animal Axon guidance sense organs Neuroscience Ephrins 030217 neurology & neurosurgery |
Popis: | The topographically ordered retinocollicular projection is an excellent system for studying the mechanism of axon guidance. Gradients of EphA receptors in the retina and ephrin-As in the superior colliculus (SC) pattern the anteroposterior axis of the retinocollicular map, but whether they are involved in map plasticity after injury is unknown. Partial damage to the caudal SC at birth creates a compressed, complete retinotopic map in the remaining SC without affecting visual response properties. Previously, we found that the gradient of ephrinA expression in compressed maps is steeper than normal, suggesting an instructive role in compression (Tadesse et al., 2013). Here we measured EphA5 mRNA and protein levels after caudal SC damage in order to test the hypothesis that changes in retinal EphA5 expression occur that are complementary to the changes in collicular ephrin-A expression. We find that the nasotemporal gradient of EphA5 receptor expression steepens in the retina and overall expression levels change dynamically, especially in temporal retina, supporting the hypothesis. This change in receptor expression occurs after the change in ephrin-A ligand expression. We propose that changes in the retinal EphA5 gradient guide recovery of the retinocollicular projection from early injury. This could occur directly through the change in EphA5 expression instructing retino-SC map compression, or through ephrinA ligand signaling instructing a change in EphA5 receptor expression that in turn signals the retinocollicular map to compress. Understanding what molecular signals direct compensation for injury is essential to developing rehabilitative strategies and maximizing the potential for recovery. |
Databáze: | OpenAIRE |
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