Extended Data Fig. 5: Reverse correlation and oscillatory coupling of glucose fluctuations with SPW-R rate.

a, For each experiment peaks and troughs in glucose fluctuations were identified (red or black dotted lines; >1 s.d.). b, The average rate of SPW-Rs is shown when triggered on peaks in the glucose derivative (black line) and troughs in the glucose derivative (red line). Shaded area shows three s.d. of a randomly circularly permuted null distribution (100 iterations). c, The average rate of stimulations is shown when triggered on peaks in the glucose derivative (black line) and troughs in the glucose derivative (red line). Shaded area, three s.d. of a randomly circularly permuted null distribution (100 iterations). d, Average power–power comodulogram at different frequencies of the glucose signal (y axis) and SPW-R rate signal (x axis) for 30 rats. Note that the patch of high correlations (R > 0.2) from 15–60 min is shifted upward, off of the diagonal. This indicates the SPW-R rate at slightly higher frequencies modulates glucose fluctuations at a slightly lower frequency, a hall-mark of phase-resetting mechanisms in biological systems. P < 1⁻²⁴ using a Student’s t-test with circularly shuffled data. e, Top, phase–amplitude coupling for each rat when using the phase angle of the glucose fluctuation signal (x axis) and SPW-R rate as the amplitude (colour; each rat is z-scored). Bottom, average phase–amplitude coupling across all rats. P < 1⁻¹⁸ using the Rayleigh test for non-uniformity.