Figure 4.

SEZ neurons underlie GH146^II-GAL4 optogenetically induced backward locomotion

(A) Schematic drawing of the expression pattern for the flies used in (B).

(B) Decapitated flies in the open arena show backward locomotion in the case of MDN driver lines as designated. ChR2-XXM was used to activate the neurons. Left, translational velocity ± SEM (shading). The 10-s light pulse is labeled in light blue. Right, mean translational velocity during the 10-s light pulse obtained from flies such as presented on the left for MDN driver lines driving UAS-ChR2-XXM, parental controls, and w¹¹¹⁸ flies (12 ≤ n ≤ 28, ^∗∗∗∗ p < 0.0001 for all comparisons to respective parental controls and w¹¹¹⁸, Kruskal-Wallis test followed by Dunn’s post-hoc test; see Table S1).

(C) Schematic drawing of the expression pattern for the flies used in (D).

(D) Decapitated flies in the open arena show no backward locomotion in the case of GH146^II-, NP225- and NP5288-GAL4 driver lines. UAS-ChR2-XXM was used to activate the neurons. Left, translational velocity ± SEM (shading). The 10-s light pulse is labeled in light blue. Right, mean translational velocity during the 10-s light pulse obtained from flies such as presented on the left for GH146^II-, NP225-, and NP5288-GAL4 driver lines driving UAS-ChR2-XXM and parental controls (9 ≤ n ≤ 29, ^∗p < 0.05, Kruskal-Wallis test followed by Dunn’s post-hoc test; see Table S1).

(E) Left, schematic drawing of the expression pattern for the flies used in (F). Right, expression pattern of GH146^II-GAL4 driving UAS-CsChrimson.mVenus in the presence of tsh-GAL80. Maximum intensity projection of 106 confocal sections (1 μm) through the central brain and ventral nerve cord is presented.

(F) Blocking expression in the VNC does not abolish backward locomotion in the case of GH146^II-, NP225-, and NP5288-GAL4 driver lines in the open arena. CsChrimson was used to activate the neurons. Left, translational velocity ± SEM (shading). The 2-s light pulse is labeled in light red. Right, mean translational velocity during the 2-s light pulse obtained from flies such as presented on the left for GH146^II-, NP225-, and NP5288-GAL4 driving either UAS-CsChrimson, or UAS-CsChrimson along with tsh-GAL80 which blocks expression in the VNC, and tsh-GAL80 control. (12 ≤ n ≤ 33, ^∗p < 0.05, ^∗∗∗∗p < 0.0001 for all comparisons to respective parental controls, Kruskal-Wallis test followed by Dunn’s post-hoc test; see Table S1).

(G) Left, schematic drawing of the expression pattern for the flies used to compose the light blue trace in (I). Right, expression pattern of GH146^II-GAL4 driving UAS-FRT-STOP-FRT-CsChrimson.mVenus in the presence of Otd-nls:FLPo. Maximum intensity projection of 117 confocal sections (1 μm) through the central brain and ventral nerve cord is presented.

(H) Left, schematic drawing of the expression pattern for the flies used to compose the dark blue trace in (I). Right, expression pattern of GH146^II-GAL4 driving UAS-CsChrimson.mVenus in the presence of Otd-nls:FLPo and tub-FRT-STOP-FRT-GAL80. Maximum intensity projection of 145 confocal sections (1 μm) through the central brain and ventral nerve cord is presented.

(I) Blocking expression in GH146^II-GAL4 SEZ neurons affects backward locomotion in the open arena. CsChrimson was used to activate the neurons. Left, translational velocity ± SEM (shading). The 2-s light pulse is labeled in light red. Right, mean translational velocity during the 2-s light pulse obtained from flies as presented on the left for GH146^II-GAL4 driving UAS-FRT-STOP-FRT-CsChrimson.mVenus in the presence of Otd-nls:FLPo (G, light blue), GH146^II-GAL4 driving UAS-CsChrimson in the presence of both Otd-nls:FLPo and tub-FRT-STOP-FRT-GAL80 (H, dark blue), and Otd-nls:FLPo control. Activation of GH146^II-GAL4 SEZ neurons led to significant backward locomotion (21 ≤ n ≤ 28, ^∗∗∗∗ p < 0.0001, Kruskal-Wallis test followed by Dunn’s post-hoc test; see Table S1).

See also Figure S3, Videos S4 and S5, and Table S1.