Figure 2.
Mauthner cells in des mutants are active during an escape response. A calcium-imaging trial of a desb420 mutant is shown. A, Mauthner cells in mutant larvae were backfilled with the fluorescent dye, calcium green dextran, at 4 dpf and imaged on confocal microscopy with a 63× objective. B, For quantification purposes, Mauthner cells on the right side of the hindbrain (A, arrow) were numbered 1 through 4. Fluorescence intensities were presented in pseudocolor with red being the brightest. In this trial, the plane of focus was optimized for cell 3. However, as is typically the case, all four cells were noticeably brighter after the escape when compared with the baseline of frames collected before the stimulus. The distortion in frame 6 indicates movement of the fish in response to a tap on the tail. Frames are ordered from left to right with 578 msec between frames. C, Quantification of the increase in fluorescence intensities. The fluorescence intensities for each cell (1-4) were plotted for each frame. The y-axis shows the normalized intensities (ΔF/F). The x-axis shows the time in seconds. Scale bar, 30 μm.