Figure 3.

Characterization of the “noncontact” axonal calcium response. (A) Line scans of the spatial profiles of the narrower 405-nm profile (0.5 μm FWHM, blue) and the wider profile (1 μm FWHM, red). When they have the same total power (intensity), the irradiance (on the y axes) of the narrower profile is four times larger. (B) Frequency of calcium transients in the two axonal ROIs (solid bars) and the five dendritic and somal ROIs (striped bars) in response to noncontact stimulation across a range of intensities (10–100%). Red and blue correspond to wider and narrower profiles. (C and D) Peak ΔF/F values for cells stimulated with no contact. Open circles indicate ROIs color coded as in Fig. 1E. Lines denote means of axon ROIs (green) and dendrite/soma ROIs (black). Statistical comparisons for these data are in Table S6. (E) Axonal response latencies. Red and blue histograms correspond to wider and narrower stimuli. Inset: the latency is defined as the time when ΔF/F = F + 5 SD. Statistical comparisons for data are shown in Table S7. (F) Peak values of ΔF/F for seven consecutive noncontact stimuli (0.5 μm FWHM) at increasing distances from the cell body. Ordinary one-way ANOVA test shows no difference between axon means (p = 0.8501). N represents the number of larvae; n represents the number of cells. To see this figure in color, go online.