Fig. 2

Schematic illustration of the method for calcium imaging in fast muscles. A Schematic illustration of the imaging setup. A larval fish, mounted in agarose, is positioned in a petri-dish. The dish is placed on a plate with an attached audio speaker to deliver vibration stimuli, which elicit escape movements. A screen located beneath the plate provides visual stimuli. Specifically, forward-moving gratings elicit slow swimming (shown at bottom left), while laterally moving gratings induce turn movements (shown at bottom right). Fast muscles in the mid trunk region are observed dorsally using a confocal microscope. B Schematic illustrations for imaging fast muscles. The fish express jGCaMP7f, a genetically-encoded calcium indicator, in fast muscles. The left panel provides a dorsal view, while the right panel presents a cross-sectional view. In the dorsal view, the rostral part of the body is immobilized in agarose, allowing free movement of the tail. The red-colored rectangle represents the imaging field. In the cross-sectional view, green coloring represents fast muscles. The red rectangle indicate the depth of the optical section captured during confocal imaging