Determining the role of defined collicular cell types in visual field-dependent innate behaviors

Innate behaviors are essential for survival. Visual cues mimicking a predator elicit freezing or escape reactions, whereas those indicative of prey attract an animal’s attention and prompt approach responses. Surprisingly, these different outcomes can be triggered by merely altering the position of the stimulus in the visual field. Both aversion and approach are mediated by a set of visuomotor circuits passing through the superior colliculus. We know that certain collicular cell types subserve specific actions via dedicated output pathways. However, how these neurons encode behaviorally salient visual features and whether their responses change according to the portion of the visual field they look at remains unknown. Here, I aim to investigate the role of genetically identified wide- and narrow-field neurons of the mouse superior colliculus in driving behaviors evoked by ethologically-relevant stimuli in the upper and lower visual field. To achieve this, I will use neural recordings to characterize their response properties and viral tracing methods to map their brain-wide inputs and outputs. Optogenetic inactivation of their activity while monitoring the animal’s behavior will determine the effect of their retinotopic location on behavior. Together, these results will shed light on the superior colliculus’ regional architecture, the mechanisms that govern visual field-dependent behaviors, and more generally how the brain encodes and disseminates visual information.