Figure 2.
Region specific changes in hippocampal theta and gamma power during REM sleep versus active waking behavior. (A) Example power spectra from one animal (decibels, +/− SEM across recording sites) of local currents recorded from CA1 stratum radiatum (CA1sr, n=6 sites) and dentate molecular layer (DGml, n=4 sites) sites during a single recording session including REM and waking. Theta (4–12Hz) and gamma (40–120Hz) frequency ranges are highlighted in gray. (B–D) Changes in the power (amplitude) of theta (left column) and gamma (right column) oscillations across REM and waking states (REM – Wake). Positive values indicate increases during REM sleep compared with active waking behavior. (B) Anatomical profile showing state-dependent changes in LFP power for each recording site from one recording session. (C,D) Group statistics showing changes in LFP (C) and current source density (CSD, D) power across different layers of hippocampal subregions (decibels, +/− SEM; p<0.01, Bonferroni corrected t-tests). Calculating dB = 10*log10(Voltage2), a 1–4dB change is equivalent to a 12–58% change in the voltage amplitude of the raw LFP oscillation. Abbreviations in this and subsequent figures: DG = dentate gyrus; CA = Cornu Ammonis; so = stratum oriens; sp = stratum pyramidale; sr = stratum radiatum; lm = stratum lacunosum moleculare; ml = molecular layer; gl = granule layer; hr = hilar region.