Daniel Pollak¹ (), Xinghao Li¹, Jasmine Wang¹, Markus Meister¹; ¹California Institute of Technology

Mice coordinate head and body movements during pursuit in a sequence of dynamic orienting behaviors. These behaviors take place on the scale of tens of milliseconds and are subject to modification from unexpected changes in the environment. To elicit reliable and prolonged hunting bouts, we developed a motorized gantry to maneuver prey items through an open field via a magnet beneath the floor. Mice pursued targets under two hunting paradigms: open- and closed-loop pursuit. In open-loop, the target moves along a pre-determined trajectory. In closed-loop, the target actively avoids the mouse. Food-deprived mice learned to pursue target objects, usually a chocolate chip, within minutes of being introduced to the setup. We developed a transfer function to predict orienting motions of the head and body from directional variables related to a visual target (angular target position, angular target velocity). The predictions of this transfer function accounted for 58% of the variance in head-turning movements during pursuit and 59% of the variance for body turning movements during pursuit. However, the head and the body do not respond instantaneously to visual input. Head movements were delayed by 60 ms while body movements were delayed by approximately 90-100 ms. This phenomenological approach to visual orienting during natural behavior provides a promising avenue for understanding the neural circuits that produce it by condensing a complex behavior into a few informative variables and highlighting details about sensorimotor integration, such as visual feedback delays and coordinated head-body adjustments, that may govern vigorous pursuit behavior across species.