A5107556888- Advanced Fluorescence Microscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Cell Image Analysis Techniques
- Neuroscience and Neuropharmacology Research
- Erythrocyte Function and Pathophysiology
- Cellular Mechanics and Interactions
- Cellular transport and secretion
- Microtubule and mitosis dynamics
- Lipid Membrane Structure and Behavior
- Ion channel regulation and function
- Digital Holography and Microscopy
- Force Microscopy Techniques and Applications
- Cannabis and Cannabinoid Research
- Near-Field Optical Microscopy
- Receptor Mechanisms and Signaling
- Neural dynamics and brain function
- Axon Guidance and Neuronal Signaling
- Image Processing Techniques and Applications
- 3D Printing in Biomedical Research
- Neuroscience and Neural Engineering
- Optical Coherence Tomography Applications
- Photoacoustic and Ultrasonic Imaging
- Diffusion and Search Dynamics
- Micro and Nano Robotics
- Image Processing and 3D Reconstruction
Institut de Neurophysiopathologie
2017-2025
Aix-Marseille Université
2016-2025
Centre National de la Recherche Scientifique
2015-2024
Centre de Recherche en Neurobiologie - Neurophysiologie de Marseille
2015-2020
ESPCI Paris
2004-2013
Inserm
2008-2011
Institut de Neurobiologie de la Méditerranée
2008-2011
Unité de Neurobiologie des canaux Ioniques et de la Synapse
2008-2011
ParisTech
2011
Laboratoire de Neurobiologie Cellulaire et Moléculaire
2006
Abstract Deep Learning (DL) methods are powerful analytical tools for microscopy and can outperform conventional image processing pipelines. Despite the enthusiasm innovations fuelled by DL technology, need to access compatible resources train networks leads an accessibility barrier that novice users often find difficult overcome. Here, we present ZeroCostDL4Mic, entry-level platform simplifying leveraging free, cloud-based computational of Google Colab. ZeroCostDL4Mic allows researchers...
The axon initial segment (AIS), located within the first 30 μm of axon, has two essential roles in generating action potentials and maintaining axonal identity. AIS assembly depends on a ßIV-spectrin/ankyrin G scaffold, but its macromolecular arrangement is not well understood. Here, we quantitatively determined nanoscale architecture by using stochastic optical reconstruction microscopy (STORM). First, directly demonstrate that 190-nm periodicity submembrane lattice results from...
Although actin at neuronal growth cones is well-studied, much less known about organization and dynamics along axon shafts presynaptic boutons. Using probes that selectively label filamentous-actin (F-actin), we found focal “actin hotspots” axons—spaced ∼3–4 µm apart—where undergoes continuous assembly/disassembly. These foci are a nidus for vigorous polymerization, generating long filaments spurting bidirectionally axons—a phenomenon call trails.” Super-resolution microscopy reveals...
The CB1 cannabinoid receptor (CB1R) displays a significant level of ligand-independent (i.e. constitutive) activity, either when heterologously expressed in nonneuronal cells or neurons where CB1Rs are endogenous. present study investigates the consequences constitutive activity on intracellular trafficking CB1R. When transfected HEK-293 cells, CB1R is at plasma membrane, but substantial proportion (∼85%) receptors localized vesicles. Detailed analysis CB1-EGFP shows that population mostly...
The type 1 cannabinoid receptor (CB1R) is one of the most abundant G-protein-coupled receptors (GPCRs) in brain, predominantly localized to axons GABAergic neurons. Like several other neuronal GPCRs, CB1R displays significant vitro constitutive activity (i.e., spontaneous activation absence ligand). However, a clear biological role for GPCR still lacking. This question was addressed by studying consequences on intracellular trafficking endogenous or transfected CB1Rs cultured hippocampal...
In neurons, generation and propagation of action potentials requires the precise accumulation sodium channels at axonal initial segment (AIS) in nodes Ranvier through ankyrin G scaffolding. We found that ankyrin-binding motif Nav1.2 determines channel concentration AIS depends on a glutamate residue (E1111), but also several serine residues (S1112, S1124, S1126). showed phosphorylation these by protein kinase CK2 (CK2) regulates Nav interaction with ankyrins. Furthermore, we observed is...
The axon initial segment (AIS) plays a key role in maintaining the molecular and functional polarity of neuron. relationship between AIS architecture microtubules (MTs) supporting axonal transport is unknown. Here we provide evidence that MT plus-end-binding (EB) proteins EB1 EB3 have addition to their plus-end tracking protein behavior other neuronal compartments. In mature neurons, concentrated stabilized AIS. We identified direct interaction EB3/EB1 scaffold ankyrin G (ankG). addition,...
Recent super-resolution microscopy studies have unveiled a periodic scaffold of actin rings regularly spaced by spectrins under the plasma membrane axons. However, ultrastructural details are unknown, limiting molecular and mechanistic understanding these enigmatic structures. Here, we combine platinum-replica electron optical to investigate cortical cytoskeleton axons at level. Immunogold labeling correlative super-resolution/electron allow us unambiguously resolve as braids made two long,...
Abstract Combining and multiplexing microscopy approaches is crucial to understand cellular events, but requires elaborate workflows. Here, we present a robust, open-source approach for treating, labelling imaging live or fixed cells in automated sequences. NanoJ-Fluidics based on low-cost Lego hardware controlled by ImageJ-based software, making high-content, multimodal easy implement any microscope with high reproducibility. We demonstrate its capacity event-driven, super-resolved...
Axon initial segments (AISs) generate action potentials and regulate the polarized distribution of proteins, lipids, organelles in neurons. While mechanisms AIS Na+ K+ channel clustering are understood, molecular that stabilize control neuronal polarity remain obscure. Here, we use proximity biotinylation mass spectrometry to identify proteome. We target biotin-ligase BirA* by generating fusion proteins with NF186, Ndel1, Trim46; these chimeras map organization intracellular membrane,...
During development, neural circuit formation requires the stabilization of active γ-aminobutyric acid–mediated (GABAergic) synapses and elimination inactive ones. Here, we demonstrate that, although activation postsynaptic GABA type A receptors (GABAARs) adenosine A2A (A2ARs) stabilizes GABAergic synapses, only A2AR is sufficient. Both GABAAR- A2AR-dependent signaling pathways act synergistically to produce 3′,5′-monophosphate through recruitment calcium–calmodulin–adenylyl cyclase pathway....
Abstract Non-uniform illumination limits quantitative analyses of fluorescence imaging techniques. In particular, single molecule localization microscopy (SMLM) relies on high irradiances, but conventional Gaussian-shaped laser restricts the usable field view to around 40 µm × µm. We present Adaptable Scanning for Tunable Excitation Regions (ASTER), a versatile technique that generates uniform and adaptable illumination. ASTER is also highly compatible with optical sectioning techniques such...
Abstract Live-cell super-resolution microscopy enables the imaging of biological structure dynamics below diffraction limit. Here we present enhanced radial fluctuations (eSRRF), substantially improving image fidelity and resolution compared to original SRRF method. eSRRF incorporates automated parameter optimization based on data itself, giving insight into trade-off between fidelity. We demonstrate across a range modalities systems. Notably, extend three dimensions by combining it with...
Abstract Open-3DSIM is an open-source reconstruction platform for three-dimensional structured illumination microscopy. We demonstrate its superior performance artifact suppression and high-fidelity relative to other algorithms on various specimens over a range of signal-to-noise levels. also offers the capacity extract dipole orientation, paving new avenue interpreting subcellular structures in six dimensions ( xyzθλt ). The available as MATLAB code, Fiji plugin Exe application maximize...
Clathrin-mediated endocytosis has characteristic features in neuronal dendrites and presynapses, but how membrane proteins are internalized along the axon shaft remains unclear. We focused on clathrin-coated structures initial segment (AIS) their relationship to periodic actin-spectrin scaffold that lines axonal plasma membrane. A combination of super-resolution microscopy platinum-replica electron cultured neurons revealed AIS pits form within “clearings”, circular areas devoid mesh....
In mammalian neurons, the precise accumulation of sodium channels at axonal initial segment (AIS) ensures action potential initiation. This precedes immobilization membrane proteins and lipids by a diffusion barrier AIS. Using single-particle tracking, we measured mobility chimeric ion channel bearing ankyrin-binding motif Nav1.2 channel. We found that ankyrin G (ankG) limits when coexpressed in neuroblastoma cells. Site-directed mutants with decreased affinity for ankG exhibit increased...