Reward revaluation biases hippocampal replay content away from the preferred outcome.

Abstract

The rodent hippocampus spontaneously generates bursts of neural activity (replay) that can depict spatial trajectories to reward locations, suggesting a role in model-based behavioral control. A largely separate literature emphasizes reward revaluation as the litmus test for such control, yet the content of hippocampal replay under revaluation conditions is unknown. We examined the content of awake replay events following motivational shifts between hunger and thirst. On a T-maze offering free choice between food and water outcomes, rats shifted their behavior toward the restricted outcome, but replay content was shifted away from the restricted outcome. This effect preceded experience on the task each day and did not reverse with experience. These results demonstrate that replay content is not limited to reflecting recent experience or trajectories toward the preferred goal and suggest a role for motivational states in determining replay content.