Fig. 1: Excitatory dmM CRH neurons are selectively activated during REM sleep.

a Localization of fluorescent probes against Crh mRNA in the dmM. Scale bar, 0.5 mm. b Localization of fluorescent probes against Crh mRNA (red), Vglut1 mRNA (green), and overlay of both channels (yellow). Arrowheads, cells co-expressing Crh and Vglut1. Scale bar, 30 μm. c Example EEG traces during NREM sleep, IS, and REM sleep, expanded from panel e. d Top, experimental approach for fiber photometry. Middle, coronal fluorescence images of dmM in a CRH-Cre mouse expressing GCaMP6s (green). Arrowhead, lesion from the optic fiber. Blue, Hoechst stain. Scale bars, 150 μm (main), 40 μm (inset). Bottom, heat map outlining areas with cell bodies expressing GCaMP6s. The green color code indicates the number of mice expressing the virus at the corresponding location (n = 7 mice). Coronal brain scheme adapted from the Allen Reference Atlas – Mouse Brain (atlas.brain-map.org). PH, nucleus prepositus; DPGI, dorsal paragigantocellular nucleus; MV, medial vestibular nucleus; mlf, medial longitudinal fasciculus. e Example fiber photometry recording, including EEG trace, EEG spectrogram, EMG amplitude, sleep annotation, and ΔF/F signal. EEG raw traces for selected time points (colored rectangles) are shown on an expanded timescale in panel c. Spectrogram and ΔF/F within the red box are shown on an expanded timescale in panel g. PSD, power spectral density. f Quantification of dmM CRH calcium activity (n = 7 mice). One-way repeated measures ANOVA (P = 1.38e−6), with Bonferroni post-hoc (REM vs Wake, P = 0.022; REM vs NREM, P = 0.009; REM vs IS, P = 0.008; Wake vs NREM, P = 0.035). Statistical details shown in Supplementary Table 1. g Example theta burst in the EEG spectrogram with corresponding ΔF/F signal, expanded from panel e. Each frequency was normalized by its mean power across the recording. h Linear filter mapping the normalized EEG spectrogram onto the dmM CRH neural response (n = 7 mice; Methods). Time point 0 s corresponds to the predicted neural response. Error bars indicate ± standard error of the mean (SEM). Lines, individual mice. *P < 0.05; **P < 0.01. Source data are provided as a Source Data file.