Bagot, Rosemary (McGill University)|Bagot, Rosemary (Université McGill)

Purpose

Learning about events that predict rewarding (e.g. palatable foods, sex) and aversive outcomes (e.g. predators, pain) and using this information to navigate through the environment is fundamental to survival. However, the significance of events is often not black and white but ambiguous and subject to interpretation and influenced by past experience. While a lot of research has examined how animals learn about positive and negative outcomes and the events that predict them, very little is known about how animals process ambiguity. This proposal focuses on a key question: how do animals resolve this ambiguity to optimize their behaviour in changing environments? There are considerable individual differences in how animals, respond to ambiguity, with some individuals having a propensity to interpret ambiguity in more positively and others more negatively (i.e. is the glass is half full or half empty?). The overarching goal of my research program (long-term objectives) is to uncover the biological basis of these individual differences and to understand how ambiguous events are represented within brain circuits, how this is changed by experience, and how activity within these specified brain circuits feeds back to shape future behaviour. To answer these questions we are using a mouse model of positive and negative bias where animals learn about positive and negative outcomes associated with specific cues and then are faced with previously un-encountered ambiguous cues. This specific research proposal (short-term objectives) uses two different kinds of early life experience (maternal separation or environmental enrichment) to examine how individual differences in responding to ambiguity alter neuronal activity in a key emotion/learning-related brain region sensitive to early life experience, the ventral hippocampus.