Figure 4.

Sano and PPK19 are required for TO neuron activation by high-NaCl concentrations. A, Representative fluorescence change (ΔR/R0) of CAM2.1 expressed in sano^Gal4 neurons in control and mutant larvae. Neuronal activity was measured before and after the addition of different stimuli: distilled water, 20 mm NaCl, or 300 mm NaCl. Responses to 300 mm NaCl were measured in larvae expressing either sano^dsRNA or ppk19^dsRNA in sano^Gal4 neurons (n = 4–6). The error bars represent the SEM. B, Mean FRET ratio changes. Changes were measured during the first 5 s of the stimulation of different control and mutant larvae (n = 4–6). The error bars represent the SEM. Asterisks indicate that results are significantly different (Student's t test, p < 0.05). C, Peak responses are shown in false-color scale (ΔR/R0%, right of images). Left, sano^GAL4,UAS–CAM2.1/+ before stimulation. Middle, sano^GAL4,UAS–CAM2.1/+ at 2 s after stimulation with 300 mm NaCl. Right, sano^GAL4,UAS–CAM2.1/+;UAS--sano^dsRNA/+ at 2 s after stimulation with 300 mm NaCl. The cell bodies of the neurons used for the FRET measurements are circled. Scale bar, 10 μm.