The study by Diba and Buzsáki investigates the temporal spike sequences of hippocampal place neurons in rats running on an elevated track. They found that these sequences recurred in reverse order at the end of a run, while they occurred in forward order before the run, coinciding with sharp waves. The vector distances between place fields were reflected in the temporal structure of these sequences. This bidirectional re-enactment of temporal sequences may contribute to the establishment of higher-order associations in episodic memory. The researchers recorded population activity in three rats while they ran back and forth on a linear track for a water reward. They identified preplay and replay events by detecting increases in population activity during immobility, which were correlated with sharp-wave ripples. The study also found that the temporal sequences during preplay and replay events preserved distance information between place fields on the track, suggesting that forward preplay may be more directly linked to the cellular representation of the run sequence.The study by Diba and Buzsáki investigates the temporal spike sequences of hippocampal place neurons in rats running on an elevated track. They found that these sequences recurred in reverse order at the end of a run, while they occurred in forward order before the run, coinciding with sharp waves. The vector distances between place fields were reflected in the temporal structure of these sequences. This bidirectional re-enactment of temporal sequences may contribute to the establishment of higher-order associations in episodic memory. The researchers recorded population activity in three rats while they ran back and forth on a linear track for a water reward. They identified preplay and replay events by detecting increases in population activity during immobility, which were correlated with sharp-wave ripples. The study also found that the temporal sequences during preplay and replay events preserved distance information between place fields on the track, suggesting that forward preplay may be more directly linked to the cellular representation of the run sequence.