Coordination of turn-related activity in the superior colliculus with locomotor dynamics and hippocampal representations of possible futures

Turning left or right is a core element of animal navigation. Such turns occur in precise coordination with the ongoing stepping rhythm and require internal planning for the animal’s future path. The superior colliculus (SC) is a midbrain structure involved in turning. Whether turn-related activity in the SC is coordinated with stepping and internal representations of future paths is unknown. Here, while recording from left- or right-preferring “turn cells” in the motor layers of the SC as mice navigated a Y-maze, we monitored locomotor dynamics and decoded internal representations of future paths from the hippocampus. We discovered that turn cell activity was tightly phase-locked to the stepping rhythm and modulated in coordination with hippocampal representations of future paths. The coordination of turn-related activity in the SC with stepping and internal representations of future paths may allow animals to seamlessly execute turns during locomotion while navigating toward planned destinations.