Figure 2.

Cortical HFS enhances Ca²⁺ transients in DLS astrocytes through mGluR5 activation. A, top left, C57Bl/6J mice received bilateral DLS injection of the genetically-encoded cytosolic Ca²⁺ indicator GCaMP6f under the astrocyte GfaABC1D promoter (AAV5.G, faABC1D.cytoGCaMP6f.SV40). Bottom left, Scheme of experimental configuration for two-photon Ca²⁺ imaging measurements in DLS astrocytes of horizontal brain slices. Right, Representative image of ROIs automatically generated by CALSEE in control conditions. B, Representative heatmap (left) and traces (top right) of Ca²⁺ fluorescence from ROIs (y-axis in left) before (pre), during (HFS, black box, as in other panels), and after (post) HFS delivery in control conditions. Bottom right, Time course of Ca²⁺ event probability averaged in 10-s bins in control conditions before, during, and after HFS delivery. C, left, Representative heatmap of Ca²⁺ traces from ROIs (y-axis) before, during, and after HFS delivery in the presence of MPEP. Right, Time course of Ca²⁺ event probability averaged in 10-s bins in MPEP group before, during, and after HFS delivery. D, Mean Ca²⁺ event probability 60 s before HFS (pre), during HFS (HFS), 70 s after HFS (post), and 12 min after HFS delivery (Post_12) in different pharmacological conditions (black, control, n = 11, 5 mice, pre vs HFS vs post, RM1WA, F_(10,20) = 9.082, **p = 0.0019, Dunnett; red, LY, n = 14, 3 mice, RM1WA, F_(13,26) = 24.27, ****p < 0.0001, Dunnett; green, CGP, n = 12, 2 mice, RM1WA, F_(11,22) = 24.35, ****p < 0.0001, Dunnett; brown, CPT, n = 9, 2 mice, RM1WA, F_(8,16) = 8.736, **p = 0.003, Dunnett; yellow, MPEP, n = 9, 2 mice, RM1WA, F_(8,16) = 0.6, p = 0.5; black, Control_2, n = 6, 2 mice, RM1WA, F_(5,15) = 14.63, **p = 0.0029, Dunnett). Data are presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.