Biography

Dr Julie Fabre studied medicine in France before joining UCL as part of a four-year Wellcome-funded PhD programme in neuroscience. Working under the supervision of Professors Kenneth Harris and Matteo Carandini, her doctoral research focused on visual processing in the basal ganglia (a group of structures in the brain that help control movement). She is now a Schmidt Science Fellow in Ilana Witten's lab at Princeton, where she studies the neural circuits underlying conditioned taste aversion, a form of learning in which an animal comes to avoid a taste that has been paired with illness.

Talk Title: A retrospective, novelty-gated mechanism for assigning delayed illness to flavor

How does the brain bridge the delay between a meal and subsequent illness to support associative learning? We recently found that delayed gastrointestinal malaise drives the amygdala into a neural state resembling that evoked by flavor consumption. However, it remains unclear whether this illness-driven reactivation reflects a hardwired overlap between flavor and malaise encoding in the amygdala, or a process specific to associative learning. To distinguish these possibilities, we examined two conditions in which mice consume a flavor and experience illness yet fail to form an association. First, when illness preceded novel flavor consumption (backward conditioning) mice acquired no aversion, and although malaise still activated flavor-coding neurons, it did so non-selectively, additionally recruiting other functional clusters. Second, when mice were pre-exposed to the flavor before conditioning learning was suppressed (latent inhibition), and activation of the flavor representation by malaise was again relatively non-selective. During later memory retrieval, amygdala flavor responses remained stable after forward conditioning with a novel flavor but dramatically weakened after familiarization or backward conditioning. Together, these findings support a model in which the selective reactivation of amygdala flavor representations by illness is retrospective and novelty-dependent, serving to stabilize flavor representations in support of associative learning.