Figure 11. Synaptic block of P-EN neurons disrupts E-PG activity.

(A) Walking statistics for flies across temperatures and across genotypes. (Ai) Example rotational velocity (top) and forward velocity (bottom) distributions for single trials for control (left, shi^TS expressed in Empty Gal4) and P-EN blocked (right, shi^TS expressed in the P-EN containing line R37F06, herein referred to as P-EN line 2). (Aii) Walking statistics at room temperature (RT, black) and at 31°C (red) for the control line and for two lines that express shi^TS in the P-EN neurons. P-EN line one is GAL4-VT008135. The standard deviation of the rotational velocity is plotted at top, while the median of the forward velocity is shown at bottom. Lines show the means of all values. (B) Recordings at 31°C for one fly with shi^TS expressed in empty Gal4. (Top) E-PG activity recorded in the ellipsoid body. (Center) The E-PG PVA strength. (Bottom) E-PG PVA and fly heading. The PVA is only shown when the PVA strength exceeds 0.025. (C) Same as in A, but now for a fly with shi^TS expressed in the P-EN neurons (P-EN line 2). The PVA strength is lower and the bump movement is sporadic. The PVA is only shown when the PVA strength exceeds 0.025. (D) Mean bump amplitude at RT and at 31°C for all flies and fly lines (N = 10 for the control, N = 9 for P-EN line 1, N = 10 for P-EN line 2, bootstrapping gives p=0.0056 (**) and p=6.0×10⁻⁴ (***)). (E) Comparison of the firing rate model predictions and the shi^TS data. (Left) E-PG bump amplitude as a function of the P-EN to E-PG synaptic efficacy for the firing rate model. (Center) The predicted ellipsoid body activity for three points along the curve that are marked with orange circles. (Right) The mean and standard deviation of the ellipsoid body activity across trials for the control fly shown in B and the shi^TS > P-EN line 2 fly shown in C. The synaptic efficacy for the shi^TS fly, likely less than 1, is unknown.

DOI: http://dx.doi.org/10.7554/eLife.23496.024

Figure 11—figure supplement 1. PVA behavior during turns under synaptic block.

(A) PVA strength distribution at room temperature (RT, shown in blue) and at 31°C (shown in red) across trials for the flies shown in Figure 11B and C. The flies walk forward quickly at 31°C, which causes the PVA strength distribution to shift right for the control fly. A PVA strength threshold of 0.025 is shown with the vertical black line. Only periods where the data exceeds this threshold are considered in B. (B) The change in PVA vs. the change in heading for each turn where the PVA strength exceeds 0.025 throughout the turn. A turn is defined as any sustained period where the rotational speed exceeds 15°/s. The solid colored lines show a linear fit to the data. The dotted gray lines show the condition where the change in heading equals the change in PVA. (C) Simulated PVA as a function of time given a time varying rotational velocity input (see Figure 10—figure supplement 2 for a description of the input) and a synaptic efficacy of 55%. (D) R² values for the linear fits to the change in heading vs. the change in PVA data for thresholded turns, as described in B. (E) The slopes of the linear fits for the change in heading vs. change in PVA data.

DOI: http://dx.doi.org/10.7554/eLife.23496.025