Find here all the news linked to RRI IMPACT (publications, seminars, events, AAP...)
Crédits photo - Racool_studio sur Freepik
Scientific events
Conférence CRCTB/IMPACT - Jason Woods (University of Cincinnati), “Using modern MRI to achieve improved respiratory outcomes in pediatrics", 18 march 2024, IHU Liryc
TheCRCTB andRRI IMPACT are pleased to invite you to a lecture by Professor Jason Woods (University of Cincinnati, Cincinnati Children's Hospital Medical Center). Professor Woods, invited by Gaël Dournes, will give a presentation entitled: "Using modern MRI to achieve improved respiratory outcomes in pediatrics".
Conférence IBIO/IMPACT - Michel Thiebaut de Schotten (GIN-IMN) - "A Human Brain Map of Mitochondrial Respiratory Capacity and Diversity" - March 27, 11am
The next IBIO conference will take place on Thursday March 27 at 11am in the conference room.
We will welcome Michel Thiebaut de Schotten, CNRS Senior Researcher, Team Leader of the Neurofunctional imaging group, Institute of Neurodegenerative Diseases (GIN-IMN) who will present his conference: "A Human Brain Map of Mitochondrial Respiratory Capacity and Diversity"
Abstract:
Mitochondrial oxidative phosphorylation (OxPhos) powers brain activity1,2, and mitochondrial defects are linked to neurodegenerative and neuropsychiatric disorders3,4, underscoring the need to define the brain’s molecular energetic landscape5–10. To bridge the cognitive neuroscience and cell biology scale gap, we developed a physical voxelization approach to partition a frozen human coronal hemisphere section into 703 voxels comparable to neuroimaging resolution (3×3×3 mm). In each cortical and subcortical brain voxel, we profiled mitochondrial phenotypes including OxPhos enzyme activities, mitochondrial DNA and volume density, and mitochondria-specific respiratory capacity. We show that the human brain contains a diversity of mitochondrial phenotypes driven by both topology and cell types. Compared to white matter, grey matter contains >50% more mitochondria. We show that the more abundant grey matter mitochondria also are biochemically optimized for energy transformation, particularly among recently evolved cortical brain regions. Scaling these data to the whole brain, we created a backward linear regression model integrating several neuroimaging modalities11, thereby generating a brain-wide map of mitochondrial distribution and specialization that predicts mitochondrial characteristics in an independent brain region of the same donor brain. This new approach and the resulting MitoBrainMap of mitochondrial phenotypes provide a foundation for exploring the molecular energetic landscape that enables normal brain functions, relating it to neuroimaging data, and defining the subcellular basis for regionalized brain processes relevant to neuropsychiatric and neurodegenerative disorders.
The prize is awarded by the SCF Board of Directors. It is awarded for internationally-recognized work that falls within the scope of the SCF's activities.
Mireille Blanchard-Desce entered the ENSJF in 1980, obtaining an agrégation in physical sciences and a doctorate in organic chemistry in 1989 (Université Pierre et Marie Curie) under the supervision of Jean-Marie Lehn. Mireille Blanchard-Desce has spent her entire professional career as a CNRS researcher since 198. At ENS Paris, she set up a young team to develop and optimize new chromophores for non-linear optics. During her thesis (under the supervision of Jean-Maire Lehn), she developed the first models of conductive molecular wires, then turned to the mechanisms of electron transfer in photosynthetic processes, which enabled her to direct her work towards molecular photonics and nanoscience. These studies led to the development of high-performance materials for electro-optical modulation.
In parallel with the covalent approach taken with organic nanodots, Mireille Blanchard-Desce was interested in an alternative route based on the self-assembly in water of multipolar, polarizable chromophoric motifs. Remarkably, this approach not only modulated optical properties (emission color, excitation response), but also surface properties (colloidal stability, interactions with cell membranes). In particular, these hyper-bright, modulable molecular nanoparticles have enabled two-photon microscopy angiography on small animals, tracking of individual nanoparticles in aqueous media, and two-color tracking within living cells.
Mireille Blanchard-Desce has been involved in research administration and management: unit director (UMR6510, Rennes) and team leader, elected for three terms to the CNRS Committee, coordinator and PI of two European ITN networks, numerous regional federative projects, member of the INC scientific council, among others. She plays an active role in the dissemination of knowledge through the supervision of over 30 theses and 20 post-doctoral fellows, teaching and publishing (editorial board of ChemPhysChem), expertise (ANR, LabEx, ERC, HCERES) and scientific mediation.
His work has been recognized by the CNRS, which awarded him the bronze medal in 1990 and the silver medal in 2008. She was awarded the Grand Prix Mergier-Bourdeix by the Académie des Sciences in 1999, the Palmes Académiques in 2009 and the Légion d'Honneur in 2012.
A member of the SCF, she has served on the board of the DCP and on the boards of the DCO and the French photo-physics, photochemistry and photo-sciences group.
To date, Mireille Blanchard-Desce's scientific output totals over 315 scientific articles, 1 book and 5 book chapters, 8 patents, 128 invited lectures at conferences and congresses, and around 100 seminars presented in academic and industrial settings.
Justine Couvez (ISM, LCPO, IMPACT), winner of the Mature your PhD + competition
LE RRI IMPACT congratulates Justine Couvez, doctoral student in the project and winner of the 2024 Mature Your PhD! competition. IMPACT félicite Justine Couvez, doctorante au sein du projet et lauréate du concours 2024 MAture Your PhD !
The Mature Your PhD+ competition is open to the entire Université de Bordeaux doctoral community in 2nd and 3rd year, including non-funded members. In addition to the Mature ton PhD program, which is open on a permanent basis, Mature you PhD+ is a way of recognizing your commitment. Co-constructed with the Graduate Research School and SATT AST, this is an annual competition (light pre-filing and pitch to a jury). For the 3 most convincing projects, you'll be awarded a 3-month fixed-term contract, during which you'll be able to devote yourself to this mission of innovation alongside your thesis work.
Publication - Human Brain Map of Mitochondrial Respiratory Capacity and Diversity by Mosharov EV, Rosenberg AM, Monzel AS, Osto CA, Stiles L, Rosoklija GB, Dwork AJ, Bindra S, Zhang Y, Fujita M, Mariani MB, Bakalian M, Sulzer D, De Jager PL, Menon V, Shirihai OS, Mann JJ, Underwood M, Boldrini M, de Schotten MT and Picard M. A . in bioRxiv [Preprint]
Abstract
Mitochondrial oxidative phosphorylation (OxPhos) powers brain activity, and mitochondrial defects are linked to neurodegenerative and neuropsychiatric disorders, underscoring the need to define the brain's molecular energetic landscape. To bridge the cognitive neuroscience and cell biology scale gap, we developed a physical voxelization approach to partition a frozen human coronal hemisphere section into 703 voxels comparable to neuroimaging resolution (3×3×3 mm). In each cortical and subcortical brain voxel, we profiled mitochondrial phenotypes including OxPhos enzyme activities, mitochondrial DNA and volume density, and mitochondria-specific respiratory capacity. We show that the human brain contains a diversity of mitochondrial phenotypes driven by both topology and cell types. Compared to white matter, grey matter contains >50% more mitochondria. We show that the more abundant grey matter mitochondria also are biochemically optimized for energy transformation, particularly among recently evolved cortical brain regions. Scaling these data to the whole brain, we created a backward linear regression model integrating several neuroimaging modalities, thereby generating a brain-wide map of mitochondrial distribution and specialization that predicts mitochondrial characteristics in an independent brain region of the same donor brain. This new approach and the resulting MitoBrainMap of mitochondrial phenotypes provide a foundation for exploring the molecular energetic landscape that enables normal brain functions, relating it to neuroimaging data, and defining the subcellular basis for regionalized brain processes relevant to neuropsychiatric and neurodegenerative disorders.
Publication - A double dissociation between semantic and spatial cognition in visual to default network pathways by Tirso RJ Gonzalez Alam, Katya Krieger-Redwood, Dominika Varga, Zhiyao Gao, Aidan J Horner, Tom Hartley, Michel Thiebaut de Schotten, Magdalena Sliwinska, David Pitcher, Daniel S Margulies, Jonathan Smallwood and Elizabeth Jefferies (2025), in eLife
Abstract :
Processing pathways between sensory and default mode network (DMN) regions support recognition, navigation, and memory but their organisation is not well understood. We show that functional subdivisions of visual cortex and DMN sit at opposing ends of parallel streams of information processing that support visually mediated semantic and spatial cognition, providing convergent evidence from univariate and multivariate task responses, intrinsic functional and structural connectivity. Participants learned virtual environments consisting of buildings populated with objects, drawn from either a single semantic category or multiple categories. Later, they made semantic and spatial context decisions about these objects and buildings during functional magnetic resonance imaging. A lateral ventral occipital to fronto-temporal DMN pathway was primarily engaged by semantic judgements, while a medial visual to medial temporal DMN pathway supported spatial context judgements. These pathways had distinctive locations in functional connectivity space: the semantic pathway was both further from unimodal systems and more balanced between visual and auditory-motor regions compared with the spatial pathway. When semantic and spatial context information could be integrated (in buildings containing objects from a single category), regions at the intersection of these pathways responded, suggesting that parallel processing streams interact at multiple levels of the cortical hierarchy to produce coherent memory-guided cognition.
Publication - Neurotransmitters’ white matter mapping unveils the neurochemical fingerprints of stroke by Pedro Alves, Victor Nozais, Justine Hansen and al., PREPRINT (Version 1) available at Research Square
Abstract
Distinctive patterns of brain neurotransmission frame determinant circuits for behavior. Understanding the relationship between their damage and the cognitive impairment provoked by brain lesions could provide important insights into the pathophysiology and therapeutics of highly disabling disorders, like stroke. Yet, the challenges of neurotransmitter circuits mapping in vivo have hampered this investigation. Here, we developed a novel MRI white matter atlas of neurotransmitter circuits and created a method to chart how stroke damages neurotransmitter systems, which innovatively distinguishes pre and postsynaptic disruption. We trained and tested our model in two large stroke patient samples and showed the existence of eight clusters with different neurochemical patterns. The associations with patients’ cognitive profiles were scarce, reinforcing that a cognitive network might be affected at different neurochemical levels. These findings unravel the relationship between neurotransmitters and behavior, depict the patterns of stroke neurochemical diaschisis, and open a new window for tailored neurotransmitter modulation.