title: Elastic properties of the cell surface and trafficking of single AMPA receptors in living hippocampal neurons.
abstract: Although various approaches are routinely used to study receptor trafficking, a technology that allows for visualizing trafficking of single receptors at the surface of living cells remains lacking. Here we used atomic force microscope to simultaneously probe the topography of living cells, record the elastic properties of their surface, and examine the distribution of transfected alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid (AMPA)-type glutamate receptors (AMPAR). On nonstimulated neurons, AMPARs were located in stiff nanodomains with high elasticity modulus relative to the remaining cell surface. Receptor stimulation with N-methyl-D-aspartate (NMDA) provoked a permanent disappearance of these stiff nanodomains followed by a decrease (53%) of the number of surface AMPARs. Blocking electrical activity before NMDA stimulation recruited the same number of AMPARs for internalization, preceded by the loss of the stiff nanodomains. However, in that case, the stiff nanodomains were recovered and AMPARs were reinserted into the membrane shortly after. Our results show that modulation of receptor distribution is accompanied by changes in the local elastic properties of cell membrane. We postulate, therefore, that the mechanical environment of a receptor might be critical to determine its specific distribution behavior in response to different stimuli.
authors.affiliation: Brain Mind Institute, Faculté des Sciences de la Vie, and Institut de Physique de la Matière Complexe, Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. ayersin@bio.titech.ac.jp
authors.forename: Alexandre
authors.initials: A
authors.lastname: Yersin
authors.forename: Harald
authors.initials: H
authors.lastname: Hirling
authors.forename: Sandor
authors.initials: S
authors.lastname: Kasas
authors.forename: Charles
authors.initials: C
authors.lastname: Roduit
authors.forename: Karina
authors.initials: K
authors.lastname: Kulangara
authors.forename: Giovanni
authors.initials: G
authors.lastname: Dietler
authors.forename: Frank
authors.initials: F
authors.lastname: Lafont
authors.forename: Stefan
authors.initials: S
authors.lastname: Catsicas
authors.forename: Pascal
authors.initials: P
authors.lastname: Steiner
mesh_terms: D002462:Cell Membrane / Q000502:physiology* / Q000648:ultrastructure; D004548:Elasticity; D006624:Hippocampus / Q000502:physiology* / Q000648:ultrastructure; D008560:Membrane Fluidity / Q000502:physiology*; D018625:Microscopy, Atomic Force / Q000379:methods*; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D021381:Protein Transport / Q000502:physiology*; D018091:Receptors, AMPA / Q000378:metabolism* / Q000648:ultrastructure; D013314:Stress, Mechanical
chemical_list: D018091:Receptors, AMPA