Annual Bindra lecture is held in honor of Dalbir Bindra's (1922-1980) scientific and academic contributions.
Lecture from 3.30 - 5:00 pm, followed by a Wine and Cheese Reception in the Bellini building (3655 Promenade Sir William Osler). Admission is free.
November 9, 2018 - Location: MCMED 522
Scott Waddell, Ph.D.
Professor of Neurobiology, Wellcome Principal Research Fellow
Center for Neural Circuits & Behaviour
Morning seminar (10:00am, MC 461):
Title: Mechanisms of Memory Formation and Re-evaluation in Drosophila
Memory is a fundamental property of the brain. Drosophila can learn to associate odors with reward or punishment. The resulting memories direct odor-specific approach or avoidance behaviors. Recent progress has revealed a straightforward model for learning in which specific dopaminergic neurons assign valence to odor representations in the neural ensemble of the mushroom bodies. Dopamine directed synaptic depression alters the route of odor-driven activity through the mushroom body output network. This learned configuration guides relevant behaviour. Following retrieval, these memories can be updated through the processes of extinction and reconsolidation. Our latest studies provide mechanistic neural circuit-based explanations for these fascinating and conserved phenomena.
Afternoon lecture (3:30pm, MCMED 522):
Title: Dopaminergic Control of Motivated Behaviour in the Fruit Fly
Motivational systems provide some of the control that allows animals to seek resources at the appropriate time. Behavioral expression of food-associated memory in fruit flies is constrained by satiety and promoted by hunger. Expression of water- memory is similarly dependent on thirst. We have uncovered some of the key neural elements of the respective motivational control mechanisms. In the hungry and thirsty conditions, broadly released neuropeptides inhibit the function of anatomically-restricted dopaminergic neurons to release memory expression. In the case of hunger, dopamine alters the level of GABA-ergic feedforward inhibition within the fly’s mushroom bodies. Directly stimulating or inhibiting the relevant neurons in each layer of the circuit can promote memory performance in satiated flies. Normal state-dependent control therefore emerges from a neural architecture of hierarchical inhibition. I will also discuss our most recent work, in which we have broken the system and formed memories that lead to compulsive behavior.