Current Research Areas

Dopamine modulates striatal neurons to govern both reinforcement and the willingness to work. Addictive drugs enhance dopamine release, and conversely loss of dopamine produces movement slowing and apathy in Parkinson’s Disease. To better understand these dopamine functions we use optical sensors to measure dopamine release in behaving animals, together with optogenetic and pharmacological manipulations. As one example we are using two-photon microscopy through microprisms to study fast dopamine dynamics in nucleus accumbens, over both large (~1mm) and small (~1µm) spatial scales.

Imagining Reward

Animals can learn through trial-and-error, but can also use their internal models of the world to make inferences about what *might* happen. We aim to understand how planning is combined with evaluation, to guide learning and decision-making. We use a complex maze task in which rats balance the costs and benefits of taking specific routes. We combine this with dense hippocampal recording to decode rats’ simulated trajectories, together with monitoring of value signals in nucleus accumbens and computational modeling of decision processes.

Ingestive Decision Making

Eating or drinking involves multiple types of decisions - e.g. whether to devote time to finding food, what to eat, and when to stop eating. A key challenge is that it takes time for nutrients to be absorbed after consumption. This delay makes it harder to learn what is worth eating, and whether the right amount has been ingested. In one project we are studying how dopamine and acetylcholine contribute to these decisions, using manipulations that separate feedback signals from the mouth and the gut.