Hippocampal place cell sequences encode future paths to remembered goals. This study shows that before goal-directed navigation in an open arena, the hippocampus generates brief sequences that encode spatial trajectories, biased toward progressing from the current location to a known goal. These sequences predict future behavior, even when the start and goal locations are novel. The findings suggest that hippocampal sequences previously thought to be "replay" during sleep or non-exploratory periods can also support goal-directed navigation by identifying important places and relevant paths when memory retrieval is needed.
The study used a spatial memory task where rats had to navigate to a known goal (HOME) or an unknown location (RANDOM). The researchers recorded hippocampal neurons while the rats performed the task, identifying trajectory events that represented spatial paths. These events were found to over-represent the known goal location, even when the specific combination of start and goal locations was novel. Trajectory events also showed a strong correlation with the rat's future path, indicating a planning mechanism for navigation.
The study found that trajectory events were more likely to end at the HOME location, suggesting that the hippocampus actively and flexibly reflects task demands. Trajectory events over-represented the known goal location, even when the rat was not at the goal, indicating that the hippocampus can encode future paths based on memory. The results suggest that hippocampal sequences are not only involved in replay but also in planning and navigating to remembered goals.
The study also found that trajectory events were not over-represented for non-goal locations, indicating that the hippocampus selectively encodes behaviorally relevant locations. The findings highlight the role of the hippocampus in spatial memory and navigation, and suggest that hippocampal sequences can support goal-directed behavior by encoding future paths based on memory. The study provides new insights into the function of hippocampal sequences in navigation and memory retrieval.Hippocampal place cell sequences encode future paths to remembered goals. This study shows that before goal-directed navigation in an open arena, the hippocampus generates brief sequences that encode spatial trajectories, biased toward progressing from the current location to a known goal. These sequences predict future behavior, even when the start and goal locations are novel. The findings suggest that hippocampal sequences previously thought to be "replay" during sleep or non-exploratory periods can also support goal-directed navigation by identifying important places and relevant paths when memory retrieval is needed.
The study used a spatial memory task where rats had to navigate to a known goal (HOME) or an unknown location (RANDOM). The researchers recorded hippocampal neurons while the rats performed the task, identifying trajectory events that represented spatial paths. These events were found to over-represent the known goal location, even when the specific combination of start and goal locations was novel. Trajectory events also showed a strong correlation with the rat's future path, indicating a planning mechanism for navigation.
The study found that trajectory events were more likely to end at the HOME location, suggesting that the hippocampus actively and flexibly reflects task demands. Trajectory events over-represented the known goal location, even when the rat was not at the goal, indicating that the hippocampus can encode future paths based on memory. The results suggest that hippocampal sequences are not only involved in replay but also in planning and navigating to remembered goals.
The study also found that trajectory events were not over-represented for non-goal locations, indicating that the hippocampus selectively encodes behaviorally relevant locations. The findings highlight the role of the hippocampus in spatial memory and navigation, and suggest that hippocampal sequences can support goal-directed behavior by encoding future paths based on memory. The study provides new insights into the function of hippocampal sequences in navigation and memory retrieval.