Fig. 3. Cortical astrocyte activity co-occurs with increases in gamma activity during sensory stimulation.

a Scheme of simultaneously recording astrocyte Ca²⁺ and ECoG in vivo. b Representative pseudocolor Ca²⁺ images of basal astrocyte activity and during hindpaw stimulation. Scale bar = 50 µm. c ECoG recording (black top trace), spectrograms (middle), and astrocyte Ca²⁺ levels (green bottom traces). d Astrocyte Ca²⁺ levels (green), relative gamma (30–50 Hz; black) and delta (0–4 Hz; purple) activity vs. time. Lines and shadows represent mean and SEM, respectively, as in other figures. e Relative delta activity vs. percentage of active astrocytes (n = 100 imaging planes, 3 animals). f as e but for relative gamma activity instead of relative delta activity. g Steady-state delta activity vs. the duration (D; left), frequency (F; center) and intensity (I; right) of the sensory stimulation (1-way ANOVA: duration: p = 0.21, frequency: p = 0.49, intensity: p = 0.17; n = 6 animals). h as g, but gamma activity instead of delta activity (1-way ANOVA: duration: p = 0.0005, frequency: p = 1.0e⁻⁷, intensity: p = 0.0004; n = 6 animals). Data were fit to the sigmoid function in Eq. (2) (see Methods section), where D_max, F_max, and I_max were the response maximum values over D_min, F_min, and I_min (i.e., the minimum value of the respective stimulus parameter), D_slope, F_slope, and I_slope were the respective slopes; and D₅₀, F₅₀, and I₅₀ were the stimulus parameter values at which responses were 50% of the maximum values. Mean ± SEM. ns: p > 0.05 and ***: p < 0.001 using 1-way ANOVA. Source data are provided as a Source Data file.