Détails de la réservation
- Le : 1 June 2018
- De : 11 h 30
- à : 12 h 30
- Salle : Amphi Centre Broca Nouvelle - Aquitaine
Détails de l'évènement
Steven Siegelbaum
Department of Pharmacology College of Physicians and Surgeons,
Columbia University, New York, NY
"Navigating social behavioral space through the hippocampal CA2 region"
Résumé
Although hippocampus is well known to play a central role in declarative memory, it has also been implicated in controlling innate motivated behaviors, such as feeding, mating and aggression. Is the mnemonic function of hippocampus important for the regulation of motivated behaviors or are circuits distinct from those involved in memory recruited? We have focused on the CA2 subregion of the hippocampus, a relatively small and understudied area located between CA3 and CA1 that has been difficult to study using conventional lesioning.
We developed a genetic approach to examining CA2 by generating an Amigo2-Cre line that allows for selective expression of genetically encoded tools and sensors in CA2 pyramidal neurons. Our previous results using genetic silencing of CA2 through tetanus toxin expression revealed that dorsal CA2 is critical for social memory, the ability of an animal to recognize and remember a conspecific. We now find that dorsal CA2 also promotes social aggression.
Through circuit tracing and targeted silencing of CA2 output paths, we demonstrate that social memory is mediated by dorsal CA2 projections to regions of ventral CA1 that project to the nucleus accumbens. In contrast we find that CA2 promotes social aggression by sending outputs to lateral septum, which trigger a disinhibitory circuit that enhances activation of ventro-medial hypothalamus, a region known to promote aggression. Thus distinct CA2 intra- and extra-hippocampal circuits selectively control social memory versus social aggression.
Invitant : Bordeaux Neurocampus / NBA
Responsable
- Nom : Julia GONCALVES