Extended Data Fig. 8 |. Nonlinear rectified response of lateral septum neurons to hippocampal synchrony.

a, Dorsal CA1 and CA3 projections converge within the lateral septum. Top, injection sites. Bottom, anterograde projections to the lateral septum. b, Left, black trace is one second of raw LFP recorded from CA1 pyramidal layer during running on a maze. Each row in the black raster plot indicates the action potentials from a single neuron. Grey dashed lines indicate the separation of theta cycles. The numbers below indicate the number of cells participating, and number of action potentials occurring, during each theta cycle. Right, three example SPW-Rs during sleep from the same session. In all example traces, neurons are sorted by the ordering of place fields on the maze (same sorting as left). c, Top, the proportion of theta cycles (black) and SPW-Rs (red) as a function of the hippocampal synchrony distribution. Dashed black and red vertical lines mark the position along the population synchrony axis at which 75% of all theta cycles (from left) or 75% of all SPW-Rs (from right) occurred. Bottom, the average z-scored firing rate across the lateral septum population (minimum threshold of 15 neurons) is shown as a function of the percentile of hippocampal synchrony distribution (n = 38 recordings from 5 rats). Bounds are one s.d.