DS0407 - Exploration du système nerveux dans son fonctionnement normal et pathologique

Unraveling the properties, regulation and role of AMPAR intracellular transport in synaptic plasticity – PAINT

PAINT

Plasticity and AMPAR Intracellular Transport

fondamental research

1. Analyze intracellular transport of AMPAR during basal transmission <br />2. Visualize AMPAR transport in brain slices <br />3. Find how intracellular transport is modulated during long term synaptic transmission. <br />4. Characterize the role of AMPAR subunits associated proteins and their phosphorylation in transport regulation.

Molecular biology tools to monitor vesicle trafficking: Develop tools to analyze vesicle trafficking, Develop tools for heteromeric receptors.
Imaging methods: Dual color imaging., High-resolution sectioning microscopy for brain slices imaging, Simultaneous recording of AMPAR transport and synaptic activity

• Obtain quantitative data on intracellular transport of AMPAR dynamics in cultured neurons.
• Obtain quantitative data on AMPAR intracellular transport kinetics in neurons in organotypic slices.
• Understand the role of long term synaptic transmission in the regulation of intracellular transport of AMPAR and vice-versa.
• Decipher the sites and mechanisms of membrane insertion at/near synapses of AMPAR with different history (neo-synthetized versus recycled).
• Collect data on the role of different subunits (core, auxiliary subunits and intracellular partners) and posttranslational modifications (specific mutations) on the regulation of AMPAR transport.
• Develop innovative imaging modality for imaging brain slices with high spatial and temporal resolutions.

Determine the transport characteristics of AMPA receptors when expressed in cultures of neurons or organotipic hippocampal slices.

Non

AMPA subtypes of glutamate receptors (AMPARs) mediate most excitatory synaptic transmission in the brain. Changes in receptor number tune synaptic efficacy and underlie a large fraction of synaptic plasticity. These changes in AMPAR number at synapses are controlled by a complex interplay between their intracellular transport, membrane trafficking, stabilization at synaptic sites, and recycling. The mechanisms of AMPAR membrane diffusion, stabilization and recycling at synapses have been extensively studied these recent years. In striking contrast and despite its pre-supposed fundamental importance, the contribution of intracellular transport and its regulation during basal transmission and its plasticity is not known in vertebrates. For example simple but fundamental questions remain fully open: what are the basal kinetic properties of AMPAR vesicular transport in hippocampal cultured neurons and in organotypic slices? How this transport is regulated by neuronal activity? What are the partner proteins implicated in this transport? How regulated AMPAR transport contributes to modulate receptor numbers at synapses? The main reason for our relative lack of knowledge is that moving receptors in dendrites from vertebrate neurons have never been imaged due to the lack of molecular tools and imaging capacities in dynamic imaging systems. We have just developed an experimental system that allows us for the first time to visualize and quantify the movement of individual vesicles containing AMPAR.
In this project we will use a unique combination of innovative molecular tools and new imaging methods to unravel both the properties and contribution of AMPAR intracellular transport to synaptic plasticity in physiological contexts. We will work in both the hippocampal neurons in culture and in most physiological system organotypic slices. Our aims are to: i) quantify AMPAR intracellular transport in basal conditions in mouse hippocampal cultured neurons and organotypic slices, ii) apprehend how intracellular transport of AMPARs participates to long term synaptic plasticity, iii) characterize interacting partners and molecular mechanisms involved in the transport of AMPARs.
Altogether, this project will shed new light on the fundamental properties of AMPAR intracellular transport in basal transmission and during synaptic plasticity conditions.

Project coordinator

Madame Françoise Coussen (Institut Interdisciplinaire de Neurosciences)

The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.

Partner

IINS / UMR5297 CNRS Institut Interdisciplinaire de Neurosciences
IINS / UMR5297 CNRS Institut Interdisciplinaire de Neurosciences

Help of the ANR 402,191 euros
Beginning and duration of the scientific project: October 2015 - 36 Months

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