Figure 1.

Effects of chlordimeform (CDM) and epinastine (epi) on V1's resting activity and on the responses to naturalistic optic flow. (A) Trajectory of a blowfly during semi-free flight in a cubic box with 40 cm edge length as seen from above (left) and from two sides. Head position and orientation are shown every 100 ms (red dots and lines; green and purple dots mark starting and end point, respectively). Small yellow dots indicate the head position every 10 ms. (B) Resting activity averaged over a 150-ms time window before motion onset during mean luminance. The boxplot illustrates the median as a central line and the upper/lower quartiles containing 50% of all data as box edges. The whiskers span the entire data range. N denotes the number of cells. The asterisk indicates statistical significance at the 5% significance level (Wilcoxon signed rank test). (C) Averaged responses of all V1 neurons to the stimulus illustrated in (A) (top, ipsilateral V1; bottom, contralateral V1). The response of the ipsilateral V1 neuron was measured directly. The responses of the same neuron to a mirror inverted version of the stimulus provided an approximation of the responses of the contralateral V1. The responses before drug application are shown in black, after CDM application in red, and after subsequent epinastine application in blue. The purple trace shows the difference between the state after CDM administration and the state after subsequent epinastine administration, which is, on average, the largest difference among the tested conditions. Inset displays magnifications of the response traces within the time window highlighted by the shaded area. (D) Head lift translation velocity (upper trace, black) and rotation velocities during the flight shown in (A). Velocity of rotation around the vertical head axis (yaw) in black, rotation around the frontal head axis (roll) in orange, and rotation around the transverse head axis (pitch) in green. The inset illustrates the axes of rotation and translation (same color coding as velocity traces; courtesy of C. Spalthoff).