The hippocampus is crucial for spatial navigation, spatial memory, and episodic memory formation. Hippocampal place cells exhibit spatially selective activity within an environment and are thought to form the neural basis of a cognitive map of space that supports these complex cognitive skills and mnemonic functions. Researchers have proposed that grid cells, head direction cells, and entorhinal cortex networks work alongside the hippocampus to support allocentric navigation strategies. However, the direct influence of place cell activity on spatial navigation behavior and navigation strategies had not been fully demonstrated.

Using an ‘all-optical’ combination of simultaneous two-photon calcium imaging and two-photon optogenetics, we identified and selectively activated place cells that encoded behaviorally relevant locations in a virtual reality environment. This use of VR technology, increasingly employed in spatial cognition and navigation research, enables precise control of spatial orientation and navigation cues. Targeted stimulation of a small number of place cells was sufficient to bias the behavior of animals during a spatial memory task, providing causal evidence that hippocampal place cells actively support spatial navigation, navigation memory, and decision making related to navigation ability.