However, when the stimulus was moving from back to front, these flies displayed reduced forward walking ( Figures 8F and S8), particularly at higher contrast frequencies. Finally, silencing

synaptic transmission in L4 alone did not cause any deficits in behavioral responses to translational motion ( Figures 8G, 8H, and S8). Importantly, using these reagents to silence L4 did cause defects in behavioral responses to visual stimuli that did not contain motion cues. L4-silenced flies had a diminished startle response to the appearance of the bars in no-motion control stimuli ( Figure S8), suggesting that L4 mediates transient responses to the appearance of static contrast patterns. Adriamycin cell line Moreover, when there was no delay between the appearance of the bars and the onset of their movement, L4-silenced flies modulated their forward walking speed less than control flies ( Figures 8I and 8J). This phenotype disappeared when appearance of the bars and motion were uncoupled. Thus, L4 function is not required for motion-evoked behavioral responses under the wide range of conditions tested. In summary, responses to translational Paclitaxel in vitro motion

are sensitive to manipulations of the specific individual input channels L2 and L3. Given the synergetic interactions between input channels for behavioral responses to rotational motion, we silenced L1–L4 in all possible pairwise combinations. Surprisingly, simultaneous silencing of both L1 and L2 did not enhance the L2 phenotype observed when flies were tested with translational motion cues moving in either direction (Figures 9A, 9B, and S9), contrasting the synergy previously observed for rotational stimuli (Clark et al., 2011, Joesch et al., 2010 and Rister et al., 2007; Figures 6D–6F). In addition, unlike

the striking deficits in turning responses Dichloromethane dehalogenase to rotational motion seen in flies in which L1 and L3 were simultaneously silenced, L1 did not enhance the effect of silencing L3 when using translational motion stimuli (Figures 9C, 9D, and S9). Finally, silencing L4 in combination with L1, L2 or L3 did not reveal any synergetic interactions (Figure S9). These data raised the possibility that L2 and L3 together might provide all of the inputs to behavioral responses to translational motion. To test this idea, we simultaneously silenced both cells. Such animals displayed very little modulation of forward walking speed in response to front-to-back motion and no detectable slowing in response to back-to-front motion (Figures 9E and 9F, blue traces). These latter results were statistically indistinguishable from those obtained when outer photoreceptors were silenced (Figures 9G and 9H), arguing that L2 and L3 likely represent all the inputs that guide responses to translational motion. Thus, the circuits that guide responses to translational versus rotational motion utilize different input architectures (Figure 9I).