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Ephrin-A5 modulates the topographic mapping and connectivity of commissural axons in murine hippocampus
- Source :
- Neuroscience. 141(1)
- Publication Year :
- 2005
-
Abstract
- Entorhinal and commissural/associational projections show a non-overlapping distribution in the hippocampus proper and the dentate gyrus. The expression of Ephrins and their Eph receptors in the developing hippocampus indicates that this family of axonal guidance molecules may modulate the formation of these connections. Here we focused on the role of the ephrin-A5 ligand in the development of the main hippocampal afferents. In situ hybridization showed that ephrin-A5 mRNA was detected mainly in the principal cells of the hippocampus proper and in the dentate gyrus throughout postnatal development. Immunocytochemical analyses revealed prominent expression of the EphA3 receptor, a putative receptor for ephrin-A5, in the main cells and the neuropil of the developing hippocampus. Tracing experiments in ephrin-A5(-/-) mice showed that commissural projections were transiently altered in the hippocampus proper at P5, but they were mistargeted throughout the postnatal development in the dentate gyrus. Immunocytochemistry with anti-calbindin antibodies revealed that the dentate mossy fiber projection was not altered in ephrin-A5(-/-) mice. Electron microscopy studies showed alterations in the density of synapses and spines in commissural/associational layers, but not in entorhinal layers, and in the mossy fibers in these animals. Taken together, these findings indicate that ephrin-A5 signaling is involved in the formation and maturation of synapses in the hippocampus.
- Subjects :
- Mossy fiber (hippocampus)
Calbindins
Synaptogenesis
Hippocampus
Biotin
Gene Expression
Biology
Hippocampal formation
Models, Biological
Mice
S100 Calcium Binding Protein G
Microscopy, Electron, Transmission
Neural Pathways
medicine
Ephrin
Animals
RNA, Messenger
In Situ Hybridization
Mice, Knockout
Brain Mapping
Reverse Transcriptase Polymerase Chain Reaction
General Neuroscience
Hippocampus proper
Dentate gyrus
Receptor, EphA3
Erythropoietin-producing hepatocellular (Eph) receptor
Gene Expression Regulation, Developmental
Dextrans
Ephrin-A5
Immunohistochemistry
Axons
medicine.anatomical_structure
nervous system
Animals, Newborn
Synapses
sense organs
Neuroscience
Subjects
Details
- ISSN :
- 03064522
- Volume :
- 141
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Neuroscience
- Accession number :
- edsair.doi.dedup.....e7718e439f87de7d7a31bb525c41cf38