Document Type
Article
Publication Date
2-21-2019
Abstract
Cortical networks are characterized by sparse connectivity, with synapses found at only a subset of axo-dendritic contacts. Yet within these networks, neurons can exhibit high connection probabilities, suggesting that cell-intrinsic factors, not proximity, determine connectivity. Here, we identify ephrin-B3 (eB3) as a factor that determines synapse density by mediating a cell-cell competition that requires ephrin-B-EphB signaling. In a microisland culture system designed to isolate cell-cell competition, we find that eB3 determines winning and losing neurons in a contest for synapses. In a Mosaic Analysis with Double Markers (MADM) genetic mouse model system in vivo the relative levels of eB3 control spine density in layer 5 and 6 neurons. MADM cortical neurons in vitro reveal that eB3 controls synapse density independently of action potential-driven activity. Our findings illustrate a new class of competitive mechanism mediated by trans-synaptic organizing proteins which control the number of synapses neurons receive relative to neighboring neurons.
Recommended Citation
Henderson, Nathan T.; Le Marchand, Sylvain J.; Hruska, Martin; Hippenmeyer, Simon; Luo, Liqun; and Dalva, Matthew B., "Ephrin-B3 controls excitatory synapse density through cell-cell competition for EphBs." (2019). Department of Neuroscience Faculty Papers. Paper 42.
https://jdc.jefferson.edu/department_neuroscience/42
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Language
English
Comments
This article has been peer reviewed. It is the author’s final published version in eLife, Volume 8, February 2019, Article number e41563.
The published version is available at https://doi.org/10.7554/eLife.41563. Copyright © Henderson et al.