Séminaire ISCMJ par Andrew Holmes
Mardi, 17 Avril, 2018 - 11:30

Pier Francesco Ferrari (ISC Marc Jeannerod) reçoit Andrew Holmes du Laboratory of Behavioral and Genomic Neuroscience (NIH lab, Rockville, USA). Il donnera une conférence sur:

Les approches des circuit neuronaux  dans la compréhension et le traitement des troubles de l'anxiété

Posttraumatic stress disorder (PTSD) can result from trauma that is either directly experienced or witnessed, yet most preclinical studies of traumatic fear memory involve direct experience of an innately aversive (unconditioned) stimulus (US) in association with a neutral (conditioned) stimulus (CS). Various rodent behavioral tasks have been established to assay socially acquired or enhanced fear, but the literature on observational fear learning (OFL) remains comparatively scarce. Here we used a modified version of the standard US-CS Pavlovian fear conditioning paradigm in which an ‘observer’ mouse witnesses a ‘demonstrator’ receiving repeated tone-shock CS-US pairings, while hearing the CS but not directly experiencing the US.  Employing complementary behavioral, anatomical and in vivo optogenetics and calcium fiber photometry approaches, we sought to define novel mechanisms subserving observational fear.  We demonstrate a critical contribution of the dmPFC to OFL and provide convergent correlative and causal evidence that ventral hippocampal (vHPC) inputs to the dmPFC negatively gate OFL. Together, our findings reveal a novel neural circuit underlying vicariously acquired fear, with therapeutic implications for PTSD and other anxiety disorders associated with abnormalities in socially learned threat. 

Salle du Conseil de l'ISC, 17 avril, à partir de 11h30