Fig. 1.

Calcium imaging in L2/3 and L5 of mouse barrel cortex during various running and whisking conditions. a Schematic of virtual reality setup with a head-restrained mouse on top of a rung-ladder treadmill. A sandpaper-covered cylinder (texture) can be moved in contact with the whiskers. Run speed is tracked with an encoder and the mean whisker angle is monitored with a high-speed video camera. b Example traces of whisker angle (gray), run speed (blue), and texture-rotation speed (black), illustrating the three experimental conditions: ‘No-touch’, ‘Closed-loop’, and ‘Open-loop’. The pink bottom bar indicates when the texture contacts the whiskers. The orange segment highlights the intermittent halt of texture-rotation to introduce a brief perturbation period in Closed-loop trials by uncoupling run speed and texture speed. c Confocal image of virally-induced R-CaMP1.07 expression pattern in a coronal slice of somatosensory cortex of a wild-type mouse. Scale bar is 500 µm. d Left: In vivo two-photon image of R-CaMP1.07-expressing L2/3 neurons with selected ROIs below (scale bar, 50 µm). Right: ΔF/F calcium transients of nine example neurons with simultaneously recorded mean whisker angle (gray) and running speed (blue) below. e Same as in (d) but for example L5 neurons in S1