Extended Data Fig. 1: Head-fixed climbing paradigm.
a, 3D illustration of the climbing apparatus, including the lick tube manipulator with lick tube, mounts for head fixation, and cameras. b, 3D exploded illustration of the wheel with the separate components visible, showing the slip ring, actuators, and 3D printed parts. c, Same as b, but without actuators and handholds. d, The two types of 3D printed handholds. Actuated handholds slide onto actuators. Static handholds attach to the wheel body between actuators. e, Seven video frames illustrating the range of different postures mice express during climbing. f, Flow chart illustrating data acquisition and experimental control. Blue arrows indicate command output signals. Black arrows indicate measured signals. g, Example time series during climbing: solenoid command for dispensing reward, wheel angle from optical encoder, and four channels of EMG. h, i Median (black dots, n = 9 mice) and 1st and 3rd quartiles (whiskers) for the variance captured by principal components of muscle activity time series (h) and kinematic time series (i, x- and y-coordinates for eight tracked points) from one session for each mouse. Gray lines are for individual mice. Three principal components captured the vast majority of the variance for both muscle activity and limb kinematic time series. Limb orientation is charted using video-based tracking.
