title: Regulation of NMDA-receptor synaptic transmission by Wnt signaling.
abstract: Wnt ligands are secreted glycoproteins controlling gene expression and cytoskeleton reorganization involved in embryonic development of the nervous system. However, their role in later stages of brain development, particularly in the regulation of established synaptic connections, is not known. We found that Wnt-5a acutely and specifically upregulates synaptic NMDAR currents in rat hippocampal slices, facilitating induction of long-term potentiation, a cellular model of learning and memory. This effect requires an increase in postsynaptic Ca(2+) and activation of noncanonical downstream effectors of the Wnt signaling pathway. In contrast, Wnt-7a, an activator of the canonical Wnt signaling pathway, has no effect on NMDAR-mediated synaptic transmission. Moreover, endogenous Wnt ligands are necessary to maintain basal NMDAR synaptic transmission, adjusting the threshold for synaptic potentiation. This novel role for Wnt ligands provides a mechanism for Wnt signaling to acutely modulate synaptic plasticity and brain function in later stages of development and in the mature organism.
authors.affiliation: Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Waldo
authors.initials: W
authors.lastname: Cerpa
authors.forename: Abigail
authors.initials: A
authors.lastname: Gambrill
authors.forename: Nibaldo C
authors.initials: NC
authors.lastname: Inestrosa
authors.forename: Andres
authors.initials: A
authors.lastname: Barria
mesh_terms: D000818:Animals; D017077:Culture Media, Conditioned; D004558:Electric Stimulation; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D051153:Wnt Proteins / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D016194:Receptors, N-Methyl-D-Aspartate; D051153:Wnt Proteins