title: Self-assembly and plasticity of synaptic domains through a reaction-diffusion mechanism.
abstract: Signal transmission across chemical synapses relies crucially on neurotransmitter receptor molecules, concentrated in postsynaptic membrane domains along with scaffold and other postsynaptic molecules. The strength of the transmitted signal depends on the number of receptor molecules in postsynaptic domains, and activity-induced variation in the receptor number is one of the mechanisms of postsynaptic plasticity. Recent experiments have demonstrated that the reaction and diffusion properties of receptors and scaffolds at the membrane, alone, yield spontaneous formation of receptor-scaffold domains of the stable characteristic size observed in neurons. On the basis of these experiments we develop a model describing synaptic receptor domains in terms of the underlying reaction-diffusion processes. Our model predicts that the spontaneous formation of receptor-scaffold domains of the stable characteristic size observed in experiments depends on a few key reactions between receptors and scaffolds. Furthermore, our model suggests novel mechanisms for the alignment of pre- and postsynaptic domains and for short-term postsynaptic plasticity in receptor number. We predict that synaptic receptor domains localize in membrane regions with an increased receptor diffusion coefficient or a decreased scaffold diffusion coefficient. Similarly, we find that activity-dependent increases or decreases in receptor or scaffold diffusion yield a transient increase in the number of receptor molecules concentrated in postsynaptic domains. Thus, the proposed reaction-diffusion model puts forth a coherent set of biophysical mechanisms for the formation, stability, and plasticity of molecular domains on the postsynaptic membrane.
authors.affiliation: Departments of Physics & Astronomy and Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Haselwandter
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Mehran
authors.initials: M
authors.lastname: Kardar
authors.affiliation: IBENS, Institute of Biology at Ecole Normale Supérieure, Inserm U1024, CNRS UMR5197, 46 rue d'Ulm, 75005 Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Triller
authors.affiliation: Department of Physics, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France.|Laboratoire de Physique Statistique, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Université Denis Diderot, France.
authors.forename: Rava Azeredo
authors.initials: RA
authors.lastname: da Silveira
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D007700:Kinetics; D008959:Models, Neurological; D009473:Neuronal Plasticity / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D013995:Time