Fig. 5. Imaging and perturbing PFL3 activity in the LALs supports the model.
a, Two-photon calcium imaging of the LAL of flies expressing jGCaMP7f in PFL3 neurons labelled by split-Gal4 line 57C10-AD ∩ VT037220-DBD. b, Example time series of GCaMP imaging data. In the third row, red dots mark transient increases in the LAL right – left (R − L) ΔF/F0 signal and blue dots mark transient decreases. c, The flies’ turning velocity (grey) and R – L signal (black) aligned to transient increases (top) or decreases (bottom) in the R − L signal. Insets show that the peak in the R − L asymmetry precedes the peak in turning velocity by around 100 ms. Mean ± s.e.m. across transients is shown (from ten flies). d, LAL activity plotted as a function of the fly’s heading relative to its goal angle. Mean ± s.e.m. across flies is shown. e, Stimulation of PFL3 cells in either left or right LAL while simultaneously performing calcium imaging from the same cells. We used flies that co-expressed CsChrimson and jGCaMP7f in PFL3 neurons labelled by split-Gal4 line VT000355-AD ∩ VT037220-DBD. f, Left, example trial in which we stimulated the left LAL. Bottom row, unwrapped heading zeroed at onset of stimulation. A decrease in the unwrapped heading signal means the fly turned left. Right, example trial with the right LAL stimulated. g, Fly-averaged GCaMP and turn signals (thin lines) for left (blue) and right (red) LAL stimulation of PFL3 or PFL1 cells. The thick line shows the average across flies. h, Mean ipsilateral (relative to the stimulation side) turning velocity during the 2-s stimulation period. Dots show the mean for individual flies and the mean ± s.e.m. across flies is indicated. PFL3 CsChrimson flies have a greater ipsilateral turning velocity than non CsChrimson PFL3 flies (P = 1.93 × 10−5, Welch’s two-sided t-test). PFL1 Chrimson flies show no significant change ipsilateral turning velocity relative to controls (P = 0.76, Welch’s two-sided t-test).