Fig. 2: Imaging different neuronal populations in a freely moving mouse using the remote focus mechanism.

a, Histological section showing jGCaMP7f labeling in layers 4 and 6 of mouse primary visual cortex. b, Overview images (lower) and schematics (upper) of the fiber tip to lens distances (distance D in Fig. 1a) for imaging planes sequentially acquired in L4 and L6 for which example neuronal Ca²⁺-transients are shown in c. c, Example Ca²⁺-fluorescence traces from sequential imaging of neuronal populations in layers 4 (red) and 6 (blue) in the same behavioral session from one animal. Corresponding overview images shown in b. Color coding in the time scale (bottom) corresponds with the color-coded position of the animal on the linear track shown in d. Laser power for the first and second Ca²⁺-imaging movies in layer 4 were 27 and 30 mW, respectively, and 44 mW for the movie in layer 6. d, Animal position on the linear track during the behavioral session in which the data in c were acquired. Color coding corresponds with the color-coded time scale in c. e, Overview images and example Ca²⁺-fluorescence traces from sequential imaging of multiple planes of labeled neurons in layer 4 acquired in one behavioral session. Colored border on overview images corresponds to the color of the example Ca²⁺-traces. Scale applies to all Ca²⁺-traces. Laser power for the six Ca²⁺-imaging movies shown were respectively (top (red) to bottom (black)) 26.5, 31, 33, 37, 38 and 56 mW. g, Position of the animal on the track during the acquisitions shown in e and f. Color coding as in e,f.