Fig. 3

Fig. 3 WHaloCaMP1a reports on neuronal activity in flies and mice.

a, One-photon imaging setup of head-fixed flies expressing WHaloCaMP1a labeled with dye-ligands. b, Fluorescence responses from WHaloCaMP1a₆₆₉ in head-fixed flies presented with different odors. WHaloCaMP1a was expressed in mushroom body KCs. Images were acquired from the calyx, where KCs receive dendritic inputs from the olfactory projection neurons (PNs) (insets). Green shading indicates odor presentation for 2 s. Data were from six flies, and odors were presented three times to each fly. The thick line and the shaded areas indicate means and s.e.m. across odor trials. Scale bar, 50 µm. c, AAV construct for transducing neurons in the mouse V1 and the schematic of the experimental setup for two-photon functional imaging of WHaloCaMP1a in the visual cortex of mice. The JF₅₅₂-HaloTag ligand was intravascularly injected 1 d before examining orientation selectivity of V1 neurons in the anesthetized mouse exposed to moving grafting visual stimuli of different orientations and directions. LCD, liquid crystal display. d, Representative images of a field of view in the mouse V1 showing neurons expressing WHaloCaMP1a₅₅₂ or EGFP. Scale bar, 50 µm. e, Functional imaging of V1 neurons shows the orientation selectivity map. f, Functional imaging of Ca²⁺ (WHaloCaMP1a₅₅₂ channel) or control (EGFP channel) traces (ROI 1–4) in response to drifting gratings in the directions shown above the traces. Average of five trials. Colored lines indicate means, and shadows indicate s.d. Orientation selectivity index (OSI) of cells is shown on the right. Imaging rate was 15 Hz. A representative imaging session from three imaging sessions is shown. The experiment was repeated independently 19 times in four mice with similar results.