Neural substrates of salience: Implications in perception and cognition

A major question in neuroscience is to understand how sensory information and memory influence behaviour. Dopaminergic neurons are candidates of special interest in this context: dopamine is implicated in learning and dopaminergic neurons innervate the brain widely, including regions controlling sensory perception, circadian rhythms, motivation... Memory acquisition and modulation of memory strength are independent processes, both controlled by the dopaminergic system: some neurons impart valence, whereas others impart motivational salience. The physiological mechanism by which dopamine modulates cognitive processes through salience is not known in any circuit or organism. Drosophila is a pioneer model organism at the cutting edge of the study of neural circuits: a relatively simple nervous system confers sophisticated behavioural complexity while maintaining principles of information coding and molecular conservation with other systems. This proposal aims to dissect compartmentalized contributions of dopamine to the cognitive process, specifically in the modulation of memory strength, using imaging and behavioural approaches to identify the neural circuits involved in motivational salience and how they interact with the circuits that dictate behavioural responses.