Role of mouse frontal cortex in behavioural variability

To external observers, animal behaviour has a puzzling yet ubiquitous property: its variability. Because animals adjust their decisions not only based on external inputs, but also on their internal state, similar situations can lead to different behavioural outcomes. How does such behavioural variability arise in the brain? In mice, correlative evidence points to a key role of frontal cortex, although its computations, networks, and causal mechanisms are unknown. Current challenges are that internal states are complex and hidden to experimentalists, and reliably observing large populations of neurons across states and brain regions is difficult. To solve these issues, I propose to combine behaviour, large-scale chronic recordings, and optogenetics to test the hypothesis that frontal cortex underlies behavioural variability. First, using high-throughput Neuropixels recordings, I will uncover the computations frontal cortex deploys to integrate external and internal signals and drive behaviour. Second, using functional ultrasound imaging and multi-area Neuropixels recordings, I will characterize how variability-related information flows in the networks supporting frontal cortex. Finally, using optogenetics, I will causally test the role of frontal cortex in driving behavioural variability. The results will provide fundamental advances in our understanding of the neural basis of behavioural variability, opening new avenues for future research.