Figure 9

Calcium imaging during closed-loop OMR. One-dimensional closed-loop optomotor gratings were presented to a head-fixed larva while simultaneously performing fast volumetric two-photon calcium imaging. (A) Single frame obtained from the behavior camera showing the larva’s tail with the OMR stimulus represented (stimulus spatial frequency was lower than depicted; 450 Hz tracking). The OMR stimulus was presented from the side and travelled from caudal to rostral. (B) Tail angle and stimulus velocity across the entire 1-min trial. Movement of the closed-loop OMR stimulus began at 15 s and continued for 30 s. (C) Maximum intensity z-projection overlaid with neuronal ROIs found in the medial hindbrain. 25 ROIs were selected for each z-plane and color-coded by depth. Automated ROI extraction was performed throughout the region enclosed in dotted red line which helped minimize the detection of non-somatic ROIs. (D) Z-scored ROI responses across the trial.