Fig. 3: Relationship between temporal coupling of AT neurons to SWRs and modulation by theta oscillations.

a Example of a simultaneous recording of LFP in the CA1 pyr. layer (top) and neuronal activity in the AT (bottom) during REM sleep. Red ticks indicate spikes from HD neurons, sorted according to their preferred direction during wakefulness. b Top, spikes for successive theta cycles. Bottom, histograms of spike density within theta cycles for three example neurons during REM sleep. c Theta modulation versus SWR energy for all neurons (red points indicate HD neurons). Side panels indicate distribution of each group. “Theta mod” (blue distributions) indicates the group of neurons significantly modulated by theta (p < 0.01). d Density map of theta-modulated neurons (min = 0.016) for one mouse. Note the absence of theta modulation for AD. e Z-scored SWR cross-correlograms for all theta-modulated AT neurons (equivalent to the group theta-mod in c). Neurons are sorted according to their modulation at SWR peaks. f First two jPC vectors (black and gray) of SWR cross-correlograms. g Projection of individual SWR cross-correlograms onto the first two jPCs. Point colors indicate 0-lag modulation (same color code as in e). Gray arrows indicate corresponding SWR-jPCA phase for four example neurons (green points, a-d). Theta phase distributions for the same four neurons are shown at each corner. h SWR-jPCA phase as a function of theta phase (r = 0.18, p < 0.001, circular correlation). The four example neurons are shown in green.