Hippocampal brain-machine interface-based navigation reveals CA1 representations of intended actions

The hippocampus uses external stimuli and self-motion to construct cognitive maps critical for navigation. However, these maps can also be activated independently of external inputs and movements, reflecting an internal ability to control the map. The neural basis of such internal control remains unknown. To address this, we used a brain-machine interface (BMI) to drive navigation in mice directly from real-time hippocampal activity. In this condition, CA1 place codes rapidly reconfigured to disregard locomotion-related input. By comparing BMI-controlled navigation, locomotion-controlled navigation, and passive playback of predetermined routes, we found evidence of CA1 place cell responses that emerge specifically in conditions in which animals can causally influence their travel. Our findings thus indicate that agency is represented by a distinct place cell code.