Timecourse normalization. (a) Trend curve for antennal luciferase fluctation, from Figure 5d, indicated as a dashed line superimposed on that for the data themselves (Figure 5a). (b) Normalized and detrended data. Normalization was accomplished by dividing each data point by the corresponding point on the trend curve. This leads to a mean timecourse value of 1 and preserves appearance of percentage changes for the values fluctuating about the trend line. One reflection of this treatment (as discussed in Results text) is that the (processed) luminescence oscillation in (b) appears more robust compared with (a).