Hippocampal ripples are highly synchronized neuronal population patterns reactivating past waking experiences in the offline brain. Whether the level, structure, and content of ripple-nested activity are consistent across consecutive events or are tuned in each event remains unclear. By profiling individual ripples using laminar currents in the mouse hippocampus during sleep/rest, we identified ripples in stratum pyramidale that feature current sinks in stratum radiatum (Radsink) versus stratum lacunosum-moleculare (LMsink). These two ripple profiles recruit neurons differently. Radsink ripples integrate recent motifs of waking coactivity, combining superficial and deep CA1 principal cells into denser, higher-dimensional patterns that undergo hour-long stable reactivation. By contrast, LMsink ripples contain core motifs of prior coactivity, engaging deep cells in sparser, lower-dimensional patterns that undergo a reactivation drift to gradually update their pre-existing content for recent wakefulness. We propose that ripple-by-ripple diversity supports parallel reactivation channels for integrating recent wakefulness while updating prior representations.
Journal article
2025-12-17T00:00:00+00:00
113
4245 - 4262.e17
CA1, hippocampus, network patterns, neuronal populations, offline computations, principal cells, reactivation, ripples, sleep, Animals, Mice, Hippocampus, Neurons, Wakefulness, Male, Sleep, Mice, Inbred C57BL, CA1 Region, Hippocampal