an overall trendp < 0.001
This is consistent with earlier studies that have reported high delta and spindle activity in the hippocampus during NREM 23 , 60 , 61 .When comparing the spectral power between the three subfields, we found that the DG/CA3 showed an overall trend of higher power than the CA1, and SUB, with certain frequency bands showing significant differences (cluster-based permutation test, p < 0.001; DG/CA3 > CA1: 10–11 Hz; DG/CA3 > SUB: 27–30 Hz; Fig. 1b and Supplementary Fig. 2b ).