title: Hippocampal plasticity requires postsynaptic ephrinBs.
abstract: Chemical synapses contain specialized pre- and postsynaptic structures that regulate synaptic transmission and plasticity. EphB receptor tyrosine kinases are important molecular components in this process. Previously, EphB receptors were shown to act postsynaptically, whereas their transmembrane ligands, the ephrinBs, were presumed to act presynaptically. Here we show that in mouse hippocampal CA1 neurons, the Eph/ephrin system is used in an inverted manner: ephrinBs are predominantly localized postsynaptically and are required for synaptic plasticity. We further demonstrate that EphA4, a candidate receptor, is also critically involved in long-term plasticity independent of its cytoplasmic domain, suggesting that ephrinBs are the active signaling partner. This work raises the intriguing possibility that depending on the type of synapse, Eph/ephrins can be involved in activity-dependent plasticity in converse ways, with ephrinBs on the pre- or the postsynaptic side.
authors.affiliation: Department of Molecular Neurobiology, Max-Planck Institute of Neurobiology, 82152 Munich-Martinsried, Germany.
authors.forename: Ilona C
authors.initials: IC
authors.lastname: Grunwald
authors.forename: Martin
authors.initials: M
authors.lastname: Korte
authors.forename: Giselind
authors.initials: G
authors.lastname: Adelmann
authors.forename: Anne
authors.initials: A
authors.lastname: Plueck
authors.forename: Klas
authors.initials: K
authors.lastname: Kullander
authors.forename: Ralf H
authors.initials: RH
authors.lastname: Adams
authors.forename: Michael
authors.initials: M
authors.lastname: Frotscher
authors.forename: Tobias
authors.initials: T
authors.lastname: Bonhoeffer
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Klein
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D036387:Ephrin-B1 / Q000378:metabolism / Q000502:physiology*; D036388:Ephrin-B2 / Q000378:metabolism / Q000502:physiology*; D036389:Ephrin-B3 / Q000378:metabolism / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D006624:Hippocampus / Q000196:embryology / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D009473:Neuronal Plasticity / Q000502:physiology*; D036081:Receptors, Eph Family / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D013569:Synapses / Q000235:genetics / Q000378:metabolism*
chemical_list: D036387:Ephrin-B1; D036388:Ephrin-B2; D036389:Ephrin-B3; D036081:Receptors, Eph Family