Characterising the fronto-cortical dopamine and serotonin dynamics underlying internal model-based decision-making

Flexible decision-making is pivotal for successfully navigating environmental challenges. As this is impaired in several psychiatric disorders, determining its underlying neural basis is crucial. Neuromodulatory systems are ideally suited for shaping adaptive decisions, however it remains unclear where and when they causally influence choice behaviour, as opposed to simply reporting decision variables. Thus, I will combine causal manipulations and activity measurements to investigate how dopamine (DA) and serotonin (5HT), both individually and in tandem, report and influence decision-making in mouse models of flexible behaviour. Particularly, I will characterise the patterns of activity and brain region specificity involved in DA's and 5HT's dynamics in relation to a flexible decision-making task, and how optogenetic manipulation of these pathways at key stages of task performance may affect subsequent choices, and activity of the other neuromodulatory system.