Neuroscience 2005 Abstract
| Presentation Number: | 942.9 |
|---|---|
| Abstract Title: | Dissociation of corticothalamic and thalamocortical axon targeting by an Epha7-mediated mechanism. |
| Authors: |
Torii, M.*1
; Levitt, P.1
1Vanderbilt Kennedy Center and Dept Pharmacol, Vanderbilt Univ., Nashville, TN |
| Primary Theme and Topics |
Development - Axonal and Dendritic Development -- Axon growth and guidance: Ephrins and receptors |
| Session: |
942. Axon Growth and Guidance: Ephrins and MAG/Nogo/RGM Poster |
| Presentation Time: | Wednesday, November 16, 2005 1:00 PM-2:00 PM |
| Location: | Washington Convention Center - Hall A-C, Board # B32 |
| Keywords: | AXON GUIDANCE, THALAMOCORTICAL, TOPOGRAPHY |
Molecular mechanisms generating reciprocal organization of corticothalamic (CT) and thalamocortical (TC) projections are poorly understood. The prevailing model suggests that CT and TC projections physically interact within the subcortical telencephalon (ST) and actively guide each other to their appropriate reciprocal targets during development. Complementary gradients of EphA and ephrin-A expression, located both between as well as within specific cortical areas and their corresponding thalamic nuclei suggested their role in the formation of topographic reciprocity of TC and CT projections. Using in utero electroporation-mediated overexpression or suppression by siRNA, we found that the expression levels of EphA7 on neocortical axons control the within-nucleus topography of CT projections. This process was independent of the relative positioning of CT axons within the ST. Notably, topographic targeting of TC axons was normal in the electroporated brains in which the topography of CT axons was disrupted. These results suggest that EphA7-mediated control of CT axon targeting is independent of the putative interactions with specific populations of TC axons. Together with their known role in TC mapping, our results support a novel model in which EphA/ephrin-A signaling controls independently the precision with which CT and TC projections develop, yet is essential for establishing their topographic reciprocity.
Supported by NIMH grant MH45507 and NICHD P30 grant HD15052
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
Copyright © 2005-2025 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
