title: Surface expression of NMDA receptor changes during memory consolidation in the crab Neohelice granulata.
abstract: The aim of the present study was to analyze the surface expression of the NMDA-like receptors during the consolidation of contextual learning in the crab Neohelice granulata Memory storage is based on alterations in the strength of synaptic connections between neurons. The glutamatergic synapses undergo various forms of N-methyl-D aspartate receptor (NMDAR)-dependent changes in strength, a process that affects the abundance of other receptors at the synapse and underlies some forms of learning and memory. Here we propose a direct regulation of the NMDAR. Changes in NMDAR's functionality might be induced by the modification of the subunit's expression or cellular trafficking. This trafficking does not only include NMDAR's movement between synaptic and extra-synaptic localizations but also the cycling between intracellular compartments and the plasma membrane, a process called surface expression. Consolidation of contextual learning affects the surface expression of the receptor without affecting its general expression. The surface expression of the GluN1 subunit of the NMDAR is down-regulated immediately after training, up-regulated 3 h after training and returns to naïve and control levels 24 h after training. The changes in NMDAR surface expression observed in the central brain are not seen in the thoracic ganglion. A similar increment in surface expression of GluN1 in the central brain is observed 3 h after administration of the competitive GABAA receptor antagonist, bicuculline. These consolidation changes are part of a plasticity event that first, during the down-regulation, stabilizes the trace and later, at 3-h post-training, changes the threshold for synapse activation.
authors.affiliation: Laboratorio de Neurobiología de la Memoria, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Universidad de Buenos Aires, IFIBYNE, CONICET. Pab. II, 2° piso, Int. Güiraldes 2160, CP 1428, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Yanil
authors.initials: Y
authors.lastname: Hepp
authors.affiliation: Laboratorio de Neurobiología de la Memoria, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Universidad de Buenos Aires, IFIBYNE, CONICET. Pab. II, 2° piso, Int. Güiraldes 2160, CP 1428, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Angeles
authors.initials: A
authors.lastname: Salles
authors.affiliation: Laboratorio de Neurobiología de la Memoria, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Universidad de Buenos Aires, IFIBYNE, CONICET. Pab. II, 2° piso, Int. Güiraldes 2160, CP 1428, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Martin
authors.initials: M
authors.lastname: Carbo-Tano
authors.affiliation: Laboratorio de Neurobiología de la Memoria, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Universidad de Buenos Aires, IFIBYNE, CONICET. Pab. II, 2° piso, Int. Güiraldes 2160, CP 1428, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Argentina ramirof@fbmc.fcen.uba.ar mpedreira@fbmc.fcen.uba.ar.
authors.forename: Maria Eugenia
authors.initials: ME
authors.lastname: Pedreira
authors.affiliation: Laboratorio de Neurobiología de la Memoria, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Universidad de Buenos Aires, IFIBYNE, CONICET. Pab. II, 2° piso, Int. Güiraldes 2160, CP 1428, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Argentina ramirof@fbmc.fcen.uba.ar mpedreira@fbmc.fcen.uba.ar.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Freudenthal
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000008:administration & dosage; D003386:Brachyura / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003463:Cues; D058787:GABA-A Receptor Antagonists / Q000008:administration & dosage; D007858:Learning / Q000502:physiology*; D008297:Male; D000069077:Memory Consolidation / Q000502:physiology*; D021122:Protein Subunits / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
chemical_list: D058787:GABA-A Receptor Antagonists; D021122:Protein Subunits; D016194:Receptors, N-Methyl-D-Aspartate; D001640:Bicuculline