Date
02
Feb 2018
Time
11:30:00
25 Rue du Dr Roux, 75015 Paris, France
Address
Building: Bâtiment Fernbach RDC
Location
2018-02-02 11:30:00
2018-02-02 12:30:00
Europe/Paris
“Adult olfactory bulb neurogenesis : adult-born neurons role and connectivity during associative learning”
Olfaction is an important sensory modality driving fundamental behaviors. During odor-dependent learning, a positive value is commonly assigned to an odorant, and multiple forms of plasticity are involved when such odor-reward associations are formed. […]
25 Rue du Dr Roux, 75015 Paris, France
About
Olfaction is an important sensory modality driving fundamental behaviors. During odor-dependent learning, a positive value is commonly assigned to an odorant, and multiple forms of plasticity are involved when such odor-reward associations are formed. In rodents, one of the mechanisms underlying plasticity in the olfactory bulb consists in recruiting daily new neurons throughout life. The majority of these cells are GABAergic interneurons called granule cells (GCs). In our experiments, we demonstrate that exposure to reward-associated odors specifically increases activity of adult-born neurons, but not neonatal-born neurons. Remarkably, adult-born neuron activation during rewarded odor presentation heightens discrimination learning and enhances the ability to update the odor value during reversal association. Moreover, activation of this interneuron population can in some cases trigger olfactory learning without sensory stimulation. This unique functional role of adult-born GCs in odor-reward association may arise from a differing connectivity. To investigate this hypothesis, we use a retrograde mono-synaptic tracing technique that enables fluorescent labelling of pre-synaptic partners contacting GCs generated at different ages. We observe that neonatal and adult-born GCs receive innervation from the same top-down regions, including the Anterior Olfactory Nucleus, the Piriform Cortex, and the Horizontal limb of the Diagonal Band of Broca/Magnocellular Preoptic nucleus. Although, our findings show that adult-born GCs received greater top-down control from these regions than neonatal-born ones, and that these connections could be modified by olfactory learning. Collectively, our study demonstrates that adult neurogenesis endows the olfactory system with the capacity to enhance odor-reward association at early stages of sensory processing, maybe due to a unique connectivity of adult-born neurons.
Location
Building: Bâtiment Fernbach RDC
Address: 25 Rue du Dr Roux, 75015 Paris, France