title: Wnt-5a modulates recycling of functional GABAA receptors on hippocampal neurons.
abstract: GABA(A) receptors (GABA(A)-Rs) play a significant role in mediating fast synaptic inhibition and it is the main inhibitory receptor in the CNS. The role of Wnt signaling in coordinating synapse structure and function in the mature CNS is poorly understood. In previous studies we found that Wnt ligands can modulate excitatory synapses through remodeling both presynaptic and postsynaptic regions. In this current study we provide evidence for the effect of Wnt-5a on postsynaptic GABA(A)-Rs. We observed that Wnt-5a induces surface expression and maintenance of this receptor in the neuronal membrane. The evoked IPSC recordings in rat hippocampal slice indicate that Wnt-5a can regulates postsynaptically the hippocampal inhibitory synapses. We found also that Wnt-5a: (a) induces the insertion and clustering of GABA(A)-Rs in the membrane; (b) increases the amplitude of GABA-currents due exclusively to postsynaptic mechanisms; (c) does not affect the endocytic process, but increases the receptor recycling. Finally, all these effects on the GABA(A)-Rs are mediated by the activation of calcium/calmodulin-dependent kinase II (CaMKII). Therefore, we postulate that Wnt-5a, by activation of CaMKII, induces the recycling of functional GABA(A)-Rs on the mature hippocampal neurons.
authors.affiliation: Centro de Envejecimiento y Regeneración, Centro de Regulación Celular y Patología Joaquín V. Luco, Instituto Milenio, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8331010 Santiago, Chile.
authors.forename: Loreto
authors.initials: L
authors.lastname: Cuitino
authors.forename: Juan A
authors.initials: JA
authors.lastname: Godoy
authors.forename: Ginny G
authors.initials: GG
authors.lastname: Farías
authors.forename: Andrés
authors.initials: A
authors.lastname: Couve
authors.forename: Christian
authors.initials: C
authors.lastname: Bonansco
authors.forename: Marco
authors.initials: M
authors.lastname: Fuenzalida
authors.forename: Nibaldo C
authors.initials: NC
authors.lastname: Inestrosa
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004594:Electrophysiology; D004705:Endocytosis / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D006624:Hippocampus / Q000378:metabolism*; D053444:Inhibitory Postsynaptic Potentials / Q000502:physiology; D055369:Miniature Postsynaptic Potentials / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D018709:Statistics, Nonparametric; D013569:Synapses / Q000378:metabolism*; D051153:Wnt Proteins / Q000378:metabolism*; D000071818:Wnt-5a Protein
chemical_list: D011963:Receptors, GABA-A; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C491837:Wnt5a protein, rat; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2