|PDF Version||Odor Perception and Memory|
|Director : Pierre-Marie LLEDO (firstname.lastname@example.org)|
The olfactory system has become an important model for investigating sensory processing as well as the cellular basis of learning and memory. We are investigating how the external word of scents may sculpt the activity of the first central relay of the olfactory system, i.e., the main olfactory bulb (OB). This relay is also one of the few regions of the brain to continuously replace one of its neuronal populations: the local GABAergic interneurons. How the newly formed neurons integrate into a pre-existing neural network and how basic olfactory functions are maintained when a large percentage of neurons are subjected to continuous renewal, are important questions that we are currently exploring. In particular, we are analyzing the sensitivity of the bulbar neurogenesis on the level of sensory inputs and, in turn, how the neurogenesis may adjust the neural network functioning to optimize odor information processing. Our results, though correlative so far, suggested that adult-born interneurons integrate functionally into the adult OB and bring specific functions to the pre-existing neuronal circuitry. We are now exploring the functional consequences of the adult neurogenesis and how it may be appropriate for the sense of smell. It is worth mentioning that these investigations not only provide new fuel for the molecular and cellular bases of sensory perception but should also shed light onto the cellular bases of learning and memory.
In 2002, our activity was aimed at understanding adult neurogenesis: the factors controlling generation, migration and integration of new neurons in adult brains and the functional consequences of this phenomenon. We have achieved this through a multidisciplinary, fully integrated approach. Methodologically this had included morphological, electrophysiological, and molecular characterization of new neurons in vitro and in vivo as well as behavior approaches to investigate the functional contribution of new neurons to pre-existing brain circuitry. Special emphasis was given to investigate the relative contribution of intrinsic (cell-autonomous) and extrinsic (environmental) cues regulating this process. Using the adult OB as a model, we investigated how neurons proliferate, differentiate, migrate and populate the different layers of the adult OB. We also explored the possible consequences of the bulbar plasticity for olfactory performances.
1) Characterization of adult-generated neurons (cellular physiology, morphology, immuno-histochemical profiles)
2) Understanding the molecular and environmental factors affecting neuronal proliferation, migration and differentiation of adult-generated neurons
3) Identification of environmental factors affecting neuronal proliferation, migration and differentiation of adult-generated neurons
4) The contribution of the medial ganglionic eminence during brain development
5) Understanding the functional consequences of adult neurogenesis at the behavioral level
6) Behavioral relevance of bulbar neurogenesis during brain development and adulthood
7) Seeking for the function of PrPC in adult neurogenesis
Photo 1 : Trophic factors in the main olfactory bulb.
Photo 2 : Odor-induced oscillations in the main olfactory bulb.
Keywords: Development, Interneuron, Oscillations, Prion, Stem cells
|More informations on our web site|
|Publications of the unit on Pasteur's references database|
|Office staff||Researchers||Scientific trainees||Other personnel|
|NAUBRON Christine, Secretary, (email@example.com)||LLEDO Pierre-Marie (Principal Investigator, DR2, C.N.R.S.) (firstname.lastname@example.org)
GHEUSI Gilles (Assistant Professor, Paris XIII) (email@example.com)
|DeCHEVIGNY Antoine, PhD student, bourse MENRT
DAVENNE Marc, Postdoc, bourse FSER
GROSMAITRE Xavier, Postdoc, bourse ROUX
LAGIER Samuel, PhD student, bourse MENRT
LEMASSON Morgane, PhD student, bourse MENRT
ROCHEFORT Christelle, PhD student, bourse MENRT
SAGHATELYAN Armen, Postdoc, bourse Institut Pasteur
|GABELLEC Marie-Madeleine (Engineer, Institut Pasteur) (firstname.lastname@example.org)|