News

Dernière mise à jour : le 16/01/2025

Find here all the news linked to RRI IMPACT (publications, seminars, events, AAP...)

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Scientific events

Conférence IBIO/IMPACT - Lucy Kershaw & John Keen (Edimbourg) - "Investigating structure and function in the equine heart" - January 17, 11am

The next IBIO conference will take place on Friday January 17 at 11am in the conference room.

We will welcome Lucy Kershaw from Centre for Cardiovascular Science and Edinburgh Imaging Facilities and John Keen from The Royal School of Veterinary Studies and The Roslin Institute who will give the following lecture about diffusion MRI and equine MRI who will present their conference: "Investigating structure and function in the equine heart"

Summary

The Thoroughbred is the consummate athletic performer amongst mammalian species, to a great extent as a consequence of its relatively large heart. Despite the importance of the heart for performance, relationships between its structure and function are poorly understood. Furthermore the so-called ‘athletic heart’ also puts the horse at risk of cardiac rhythm abnormalities that are associated with altered structure and function.
We are interested in deducing the relationship between structure and function in the equine heart, in health and disease, using novel imaging technologies. This presentation will outline our preliminary work in this area and the goals we aim to achieve.

You can also attend these two conferences via this zoom link: https://u-bordeaux-fr.zoom.us/j/89010340808?pwd=txbQzGhDueBuoEbq7SHLVeYT4Qf1PT.1

Lucy Kershaw is a Reader at University of Edinburgh and an MRI physicist working at the Edinburgh Imaging Facility QMRI. Before coming to Edinburgh, she worked in Manchester and Toronto, and her research focuses on the use of quantitative MRI in health and disease. She worked on quantitative imaging, accuracy and precision in DCE-MRI, T1 measurement, and comparison with other imaging modalities. Application of functional imaging to treatment planning, treatment monitoring and prognosis in a wide range of diseases and body areas including normal uterus and pancreas, and cancer of the prostate, cervix, bladder, head and neck. Recent work has been on novel contrast agents (Manganese, iron oxide) and joint imaging in the horse.

John Keen is a senior clinician in the Equine Hospital and Chair of Equine Cardiovascular Science. His clinical and research interests include all aspects of internal medicine, but with particular emphasis on cardiovascular disease, metabolic and endocrine disease and the potential links between these disorders. John has extensive experience in equine clinical cardiology in particular and, with two colleagues, runs a peripatetic transvenous electrocardioversion (TVEC) service for treating atrial fibrillation in horses, across the UK.

Contacts:

- Valéry Ozenne (valery.ozenne@u-bordeaux.fr)

- Julie Magat (julie.magat@ihu-liryc.fr)

- Hervé Lemaître (herve.lemaitre@u-bordeaux.fr)

- Fanny Munsch (fanny.munsch@u-bordeaux.fr)

Conférence IBIO/IMPACT - Pierrick Coupé (LaBRI) - "Deep Learning for Quantitative Analysis of Brain MRI" - January 23, 11am

The next IBIO conference will take place on Thursday January 23 at 11am in the conference room.

We will welcome Pierrick Coupé, CNRS Research Director from the Laboratoire Bordelais de Recherche en Informatique (LaBRI - In2Brain Research Group) who will present his conference: " Deep Learning for Quantitative Analysis of Brain MRI"

Abstract:

This conference will present our work dedicated to the quantitative analysis of cerebral MRIs, from the development of innovative methods to the production of new knowledge. First, I will present some of our brain analysis methods based on collective artificial intelligence. Then, I will describe our open access platform integrating our brain MRI segmentation tools. . Finally, I will present our recent BigData studies dedicated to lifespan modeling of normal aging and diseased brain.

You can also attend these two conferences via this zoom link: https://u-bordeaux-fr.zoom.us/j/88984884813?pwd=U1lxvO9orxn33w4GkP9DaUmfIKstIl.1

Contacts:

- Hervé Lemaître (herve.lemaitre@u-bordeaux.fr)

- Fanny Munsch (fanny.munsch@u-bordeaux.fr)

Call for projects

No call for the moment.
See you soon!

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New publications

Publication - A lactate-dependent shift of glycolysis mediates synaptic and cognitive processes in male mice by Fernandez-Moncada, I., G. Lavanco, U. B. Fundazuri, N. Bollmohr, S. Mountadem, T. Dalla Tor, P. Hachaguer, F. Julio-Kalajzic, D. Gisquet, R. Serrat, L. Bellocchio, A. Cannich, B. Fortunato-Marsol, Y. Nasu, R. E. Campbell, F. Drago, C. Cannizzaro, G. Ferreira, A. K. Bouzier-Sore, L. Pellerin, J. P. Bolanos, G. Bonvento, L. F. Barros, S. H. R. Oliet, A. Panatier and G. Marsicano, Nat Commun

Abstract

Astrocytes control brain activity via both metabolic processes and gliotransmission, but the physiological links between these functions are scantly known. Here we show that endogenous activation of astrocyte type-1 cannabinoid (CB1) receptors determines a shift of glycolysis towards the lactate-dependent production of d-serine, thereby gating synaptic and cognitive functions in male mice. Mutant mice lacking the CB1 receptor gene in astrocytes (GFAP-CB1-KO) are impaired in novel object recognition (NOR) memory. This phenotype is rescued by the gliotransmitter d-serine, by its precursor l-serine, and also by lactate and 3,5-DHBA, an agonist of the lactate receptor HCAR1. Such lactate-dependent effect is abolished when the astrocyte-specific phosphorylated-pathway (PP), which diverts glycolysis towards l-serine synthesis, is blocked. Consistently, lactate and 3,5-DHBA promoted the co-agonist binding site occupancy of CA1 post-synaptic NMDA receptors in hippocampal slices in a PP-dependent manner. Thus, a tight cross-talk between astrocytic energy metabolism and gliotransmission determines synaptic and cognitive processes.

Publication - Neuroprotective effects of lactate and ketone bodies in acute brain injury by Plourde, G., H. Roumes, L. Suissa, L. Hirt, E. Doche, L. Pellerin, A. K. Bouzier-Sore and H. Quintard, J Cereb Blood Flow Metab

Abstract :

The goal of neurocritical care is to prevent and reverse the pathologic cascades of secondary brain injury by optimizing cerebral blood flow, oxygen supply and substrate delivery. While glucose is an essential energetic substrate for the brain, we frequently observe a strong decrease in glucose delivery and/or a glucose metabolic dysregulation following acute brain injury. In parallel, during the last decades, lactate and ketone bodies have been identified as potential alternative fuels to provide energy to the brain, both under physiological conditions and in case of glucose shortage. They are now viewed as integral parts of brain metabolism. In addition to their energetic role, experimental evidence also supports their neuroprotective properties after acute brain injury, regulating in particular intracranial pressure control, decreasing ischemic volume, and leading to an improvement in cognitive functions as well as survival. In this review, we present preclinical and clinical evidence exploring the mechanisms underlying their neuroprotective effects and identify research priorities for promoting lactate and ketone bodies use in brain injury.

Keywords: Alternative brain fuels; TBI; brain metabolism; hypoxia; ketone bodies; lactate; neuroprotection; stroke.

Publication - Whole-brain T2 mapping with radial sampling and retrospective motion correction at 3T. by Corbin N, Trotier AJ, Anandra S, Kadalie E, Dallet L, Miraux S, and Ribot EJ, Magn Reson Med.

Abstract

Purpose: Several barriers prevent the use of whole-brain T2 mapping in routine use despite increasing interest in this parameter. One of the main barriers is the long scan time resulting in patient discomfort and motion corrupted data. To address this challenge, a method for accurate whole-brain T2 mapping with a limited acquisition time and motion correction capabilities is investigated.

Methods: A 3D radial multi-echo spin-echo sequence was implemented with optimized sampling trajectory enabling the estimation of intra-scan motion, subsequently used to correct the raw data. Motion corrected echo images are then reconstructed with linear subspace constrained reconstruction. Experiments were carried out on phantom and volunteers at 3T to evaluate the accuracy of the T₂ estimation, the sensitivity to lesions and the efficiency of the correction on motion corrupted data.

Results: Whole-brain T₂ mapping acquired in less than 7 min enabled the depiction of lesions in the white matter with longer T₂. Data retrospectively corrupted with typical motion traces of pediatric patients highly benefited from the motion correction by reducing the error in T₂ estimates within the lesions. All datasets acquired on seven volunteers, with deliberate motion, also showed that motion corrupted T₂ maps could be improved with the retrospective motion correction both at the voxel level and the structure level.

Conclusion: A whole-brain T₂ mapping sequence with retrospective intra-scan motion correction and reasonable acquisition time is proposed. The method necessitates advanced iterative reconstruction strategies but no additional navigator, external device, or increased scan time is required.

Keywords: T2 mapping; motion correction; radial sampling.