Fig. 1: Stability of HD decoding before SWRs.

a–e HD decoding with ISOMAP around time of SWRs for one example session. a Tuning curves of HD neurons recorded simultaneously in the AD nucleus. b Simultaneous recording of CA1 pyramidal layer LFP (top) and neuronal activity in AD (same neurons as in a) around the time of SWRs during NREM sleep. Spikes from HD neurons are sorted according to their preferred direction during wakefulness (as in a). Red asterisks indicate SWRs. c Two-dimensional embeddings (using ISOMAP) of HD neuronal population activity during wakefulness and around the times of SWRs (colored and gray points, respectively). Curves display the population activity embeddings of the three examples shown in b (same red asterisks). d Distribution of distances from the embedding center (c) during wakefulness (blue) and NREM sleep (gray). e Distribution of average angular directions around the time of SWRs (±30 ms). f Average normalized radii (i.e. distance from embedding centers relative to shuffles) around times of SWRs (gray lines; n = 7 sessions, 3 animals) and session-wide average (black line). g Same as f for angular velocity (i.e. angular displacement between two consecutive activity bins). h Average density of spikes (±s.e.m.) for simultaneously recorded HD (black) and non-HD (gray) neurons, and rate of occurrence of SWRs (red line) during DOWN and UP states (normalized time).