CRCA teams
Group leaders: Martin GIURFA & Jean-Marc DEVAUD
The objective of our team is the integrative study of experience-dependent plasticity in insects, with a particular focus on cognitive functions, such as visual and olfactory learning and memory. Three model species (honeybee, bumblebee, Drosophila), for which detailed descriptions of brain anatomy and genome are now available, are used to explore behavioral plasticity in ecologically relevant tasks and to track down their genetic, molecular and neural mechanisms bases. The comparative analysis between species exhibiting various levels of social complexities provides a unique opportunity to consider experience-dependent plasticity in a social context.
Our multidisciplinary approach is poised at the interface between experimental psychology, neurobiology, molecular biology, behavioral genetics and cognitive ecology. We use state-of-the-art techniques spanning from behavioral observations of free-flying bees foraging on computer-controlled flowers, to the conditioning of harnessed individuals presented with tightly controlled stimuli, the identification of neural circuits involved in memory formation using transgenes, and the detailed tracking of neurotransmission processes in targeted brain structures.
Group leaders: Audrey DUSSUTOUR & Raphaël JEANSON
The main objective of the IVEP team is to develop an integrative approach to investigate the determinants of phenotypic plasticity across different biological scales. Phenotypic plasticity is the capacity of a given genotype to produce a diversity of phenotypes in response to variations in the environment and represents one of the most important ways by which organisms adaptively respond to the environment. Depending on the system under study, environmental variations can range from local changes in the surroundings of cells to the ecological fluctuations experienced by individuals and their impact can span different temporal scales, from instantaneous to generational, with a transient or permanent incidence on the expression of phenotypic traits.
The IVEP team ambitions to investigate how biological entities, being cells or individuals, integrate environmental changes to produce adaptive responses and it also aims at examining how phenotypic plasticity emerges from interactions among its underlying components. For its scientific project, IVEP thus proposes to address complementary questions ranging from cell plasticity to behavioural variability in social groups.
Group leader: Claire RAMPON
Research projects carried out in the team will address the fundamental question of how enduring memories are formed in the brain, therefore placing our goals and strategy at the core of the CRCA’s main focus on phenotypic and experience-dependent plasticity.
We are studying more specifically mechanisms of cerebral plasticity related to spatial and episodic memory in normal mice and in mouse models of memory dysfunctions or pathologies. We will focus on learning-induced plasticity processes at different levels from the activity of neuronal networks (cerebral oscillations, synaptic plasticity, inhibitory networks), to cells (neurogenesis, morphology of neurons or glial cells, interactions between neurons and glia), neurobiological issues (protein or gene expression, release of neurotransmitters, role of mitochondria) to finally work at the molecular level (epigenetic regulations, role of transcriptional factors).
These mechanisms are also studied in the context of normal and pathological aging (mostly Alzheimer’s disease) and also in mouse models of mood disorders (mostly post traumatic stress disorders).
We used multiple and complementary approaches: behavioral analysis, electrophysiology in behaving animals, EEG, pharmacology, intracerebral microdialysis, confocal imaging, molecular and cellular biology.
Group leader: Vincent FOURCASSIE
The main objective of our team is to understand the behavioural and cognitive mechanisms underlying collective behaviours and collective decisions in groups of animals. Our aim is to identify the mechanisms that allow a group of animals to coordinate their actions and to provide adaptive collective responses to the changes occurring in its environment, i.e. to display collective intelligence. We try to understand in particular how the ability of a group to solve problems collectively varies with the properties of the individuals it is composed of. The general methodology of our work is based on a tight combination of experimental and modeling approaches.
Group leader: Pascale BELENGUER
Mitochondria morphology varies according to cell type and cellular context from an interconnected filamentous network to isolated dots. This morphological plasticity depends on mitochondrial dynamics, a balance between antagonistic forces of fission and fusion. DRP1 and FIS1 control mitochondria outer membrane fission and mitofusins its fusion. Our team has identified one of the few known actors of inner membrane dynamics, OPA1, which mutations provoke an optic neuropathy (type 1 Dominant Optic Atrophy, ADOA-1).
During the last 5 years we focused our work on the molecular and functional characterization of OPA1 and of its yeast homologue Msp1, as well as on the pathophysiological mechanisms leading to ADOA-1. Mitochondrial dynamics influences the main functions of the organelle (respiration, calcium homeostasis, ROS production, apoptosis) and its distribution. Consequently, this phenomenon is due to play a major role in neurons because of their highly specialized nature and architecture as well as their plasticity during development and adulthood. A definite proof of the major role of mitochondrial dynamics in the nervous system came from the discovery that mutations in key actors of this process are responsible for neurodegenerative disorders.
While pursuing our investigations on the influence of mitochondrial dynamics, and of OPA1, on neurodegeneration, we start now to study the impact of mitochondrial dynamics on the functions and plasticity of mature and developing neurons.