The study by Pfeiffer and Foster investigates the role of hippocampal place cells in goal-directed navigation. They found that before goal-directed navigation in an open arena, the hippocampus generates brief sequences of place cell activity that encode spatial trajectories biased towards a known goal location. These sequences predict immediate future behavior, even when the specific combination of start and goal locations is novel. The researchers used a task where rats had to navigate to a reward in a random location (RANDOM) and then to a predictable reward location (HOME). They recorded from hippocampal neurons and identified "trajectory events" during periods of immobility, which showed strong representation of the HOME location, even when the rats were not at HOME. These trajectory events were more closely aligned with the rats' future path to HOME compared to their past path, suggesting a planning mechanism for goal-directed navigation. The findings suggest that hippocampal sequence events, previously thought to be 'replay' during sleep or non-exploratory awake periods, can also support goal-directed navigation by identifying important places and relevant behavioral paths.The study by Pfeiffer and Foster investigates the role of hippocampal place cells in goal-directed navigation. They found that before goal-directed navigation in an open arena, the hippocampus generates brief sequences of place cell activity that encode spatial trajectories biased towards a known goal location. These sequences predict immediate future behavior, even when the specific combination of start and goal locations is novel. The researchers used a task where rats had to navigate to a reward in a random location (RANDOM) and then to a predictable reward location (HOME). They recorded from hippocampal neurons and identified "trajectory events" during periods of immobility, which showed strong representation of the HOME location, even when the rats were not at HOME. These trajectory events were more closely aligned with the rats' future path to HOME compared to their past path, suggesting a planning mechanism for goal-directed navigation. The findings suggest that hippocampal sequence events, previously thought to be 'replay' during sleep or non-exploratory awake periods, can also support goal-directed navigation by identifying important places and relevant behavioral paths.