Figure 4.

A circuit ablated by larval hydroxyurea treatment is required for yaw olfactory-mediated optomotor modification. Wild-type animals increase wingbeat frequency in the presence of an attractive odor, apple-cider vinegar (ACV), but not due to a switch to water stimuli (W). A, B, Similar to wild-type animals, HU-treated flies significantly increase their WBF in the presence of odor (A) and decrease the variance of sideslip responses in the presence of odor (B). C, Treatment with HU results in a loss of olfaction-dependent changes in gain in both yaw and sideslip filters (yaw no-odor N = 49, yaw odor N = 47, sideslip no-odor N = 57, sideslip odor N = 59), although the sideslip height shows a decreasing trend (p = 0.25). D, Neither filter shows olfaction-dependent changes in prediction–response correlation. E, Similar to wild-type animals, HU-treated flies can localize an odor source hidden in the floor in a walking trap assay, albeit with a slower time course than wild-type animals. F, The predicted yaw response to the sinusoidal stimulus in the presence of odor has much lower amplitude than the actual wild-type odor response. *p < 0.05, **p < 0.01, ***p < 0.001.