Fig. 3: Nearly all MEC neurons are locked to the oscillatory sequences.
From: Minute-scale oscillatory sequences in medial entorhinal cortex
a, Left, locking degrees of neurons from the session shown in Fig. 2a. Black dots indicate locked neurons; red dots indicate non-locked neurons; and grey dots show the 99th percentiles of the corresponding shuffle distributions, one per cell (458 out of 484 cells were significantly locked to the phase of the oscillation). Right, similar to left, but for mutual information (MI) between phase of the oscillation and count of calcium events. Black dots indicate MI and grey dots show the estimated bias in the MI. For all cells, the MI is larger than the bias. Neurons are sorted according to ascending locking degree (left) or MI (right). b, Box plot showing percentage of locked neurons over all oscillatory sessions (median = 94%; two-sided Wilcoxon signed-rank test, n = 15 sessions, P = 6.1 × 105, W = 120). Red line shows median across sessions; blue bottom and top lines delineate bottom and top quartiles, respectively; whiskers extend to 1.5 times the interquartile range; and red crosses show outliers exceeding 1.5 times the interquartile range. c, Each row shows the tuning curve (colour coded) to the phase of the oscillation of one locked neuron in Fig. 2a (n = 458) calculated on experimental (left) and shuffled (right) data. d, Distribution of participation indexes across neurons in the session in Fig. 2a (n = 484 cells, left) and across all 15 oscillatory sessions (n = 6,231 cells, right). e, Anatomical distribution of neurons in the FOV of the session in Fig. 2a. Neuronal preferred phase is colour coded. Neurons in red are not significantly locked. Dorsal MEC on top, medial on the right. f, A two-dimensional histogram of differences in preferred phase between pairs of neurons for sequence no. 19 of the session in Fig. 2a, and their distance in the FOV. In the presence of travelling waves, high values along the diagonal would be expected. Normalized frequency is colour coded. Each count is a cell pair (n = 116,886 cell pairs for 484 recorded cells). Correlation = 0.0026, cutoff for significance = 0.0099. g, Distribution of correlation values between differences in preferred phase and anatomical distance in experimental data (blue bars, n = 421 sequences across 15 oscillatory sessions) and shuffled data (orange dotted line, n = 42,100, 100 shuffled iterations per sequence) (Methods). ***P < 0.001, **P < 0.01, *P < 0.05; NS, not significant (P > 0.05).
