Circuit principles of memory-based behavioural choice

Animals often have to choose between combinations of good and bad outcomes. For example, a child might see a dog under a cherry tree. In order to make appropriate decisions the brain must learn which stimuli predict good or bad outcomes – cherries are tasty and dogs can be dangerous. They must then determine the overall value of each decision – going over to the tree could lead to eating cherries but could also risk a dog bite, but avoiding the tree leads to neither. They must then make one choice and suppress the others. The goal of my research is to explain how brains achieve these kinds of decisions, which are critical for normal life across the animal kingdom and are disrupted in many neuropsychiatric disorders.

Nervous systems are networks of interconnected neurons. Determining the patterns of connections between neurons is an essential first step in understanding how brains work, but this is only possible for relatively small brains. We have produced a connectivity map of a memory and decision-making centre in the brain of the fruit fly larva. We will use genetic tools available in the fruit fly to manipulate and monitor the activity of individual neurons in this network and elucidate general principles by which brains make decisions.