The François Jacob Institute of Biology brings together five departments and three services
The last two years in scientific news
Group leader: Marc Dhenain (DR1CNRS,
French Veterinary Academy,
National Academy of Medicine)
Luc Bousset ; Thierry Delzescaux; Marc Dhenain; Mehdi Kabani ; Jean-Luc Picq
Anne-Sophie Hérard ; Camille Mabillon ; Fanny Petit ; Nicolas Souedet
Marina Célestine ; Lilian Mehl ; François Plumerault ; Huaqian Wu
Our group has demonstrated that Aβ and tau lesions are transmissible and can spread in the brain of mice and in primates (Gary, 2019). This transmission makes it possible to explore the pathophysiogenic mechanisms leading to the pathology.
In addition to studies in mice, we investigate Alzheimer pathology in primates (Microcebus murinus). The microcebe is a model of neurodegenerative pathologies linked to aging. This animal presents, as it ages, cognitive alterations, alterations in cerebral metabolism, cerebral atrophy and amyloid deposits.
Amyloid and tau lesions induced in the brain of experimental models following inoculation of amyloid and tau nucleating factors.
The assembly of Aβ and tau proteins into fibrils plays an essential role in mediating the self-propagation and cell-to-cell transmission of pathological amyloid fibrils in Alzheimer's disease. We aim to characterize the heterogeneity of Aβ and Tau amyloid fibrils present in humans, mice and primates and assess the relationships between this diversity and their pathological impacts.
Examples of ongoing projects
Self-replication and transcellular spread of tau proteins are responsible for the progressive accumulation of misfolded Tau protein deposits in the brain of Alzheimer's disease patients. Tau spreading correlates with the severity of cognitive decline. Our group characterizes factors mediating and regulating tau spreading as they represent relevant targets for future therapies.
Overview of the range of imaging methods implemented by our group. State of the art methods to manipulate large amounts of data and require high performance computing.
Methods used to evaluate neuronal density and other neuronal parameters based on high performance computing.Brain sections stained for cells (NeuN antibody) are segmented and various parameters reflecting neuronal characteristics(e.g. their density, size, orientation, etc…) are calculated.Based on this analysis, we can produce parametric maps reflecting neuronal states at the level of the whole brain.These maps can then be compared with other maps (lesion, brain function, etc…).
Individual cells function in a harmonized way that leads to harmonious brain activity through functional networks. These networks can be assessed by resting state functional MRI and sophisticated image processing tools. Our group studies brain activity with resting state functional imaging. Our group implemented methods to detect neuronal networks in rodents (Celestine, 2020; https://sammba-mri.github.io/; Grandjean, 2020) and primates (Garin, 2021).
Example of detection of neural networks in humans and in the smallest primate in the world (mouse lemur)by magnetic resonance imaging.
Contributions to Science
Visiting ProfessorJames Koch, Professeur,Université du Wisconsin, Oshkosh, USA
Post-docsSalma BougachaNachiketMatthias VandesquilleChrystelle PoMatthieu SantinAlexandra PetietOliviero GobboGéraldine PoisnelElmahdi Sadouni
Sébastien Piluso (2018-2022) : Automatic segmentation of individual sections of mouse brains by 3D digital atlas. PhD Thesis
Evaluation of automated segmentation algorithms for neurons in macaque cerebral microscopic images.You, Z., M. Jiang, Z. Shi, X. Ning, C. Shi, S. Du, A. S. Hérard, C. Jan, N. Souedet, Delzescaux T.Microscopy Research and Technique. 2021: 27 Apr 2021: https://doi.org/2010.1002/jemt.23786.
Clément Garin (2015-2019): "Characterization of mouse lemur brain by anatomical, functional and glutamate MRI". PhD Thesis.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.