Figure 4. No impairment of appetitive learning with water or sucrose reward in Dop1 knockout crickets.

Dop1 knockout crickets and wild-type crickets were subjected to two-trial appetitive conditioning with water (a) or sucrose (b) reward, with the ITI of 5 min. In both groups, relative preference between the rewarded odor (CS) and control odor was tested before and at 30 min after training. For conditioning with water reward, peppermint odor was used as CS and vanilla odor was used as control. For conditioning with sucrose reward, maple odor and vanilla odor were used, one of which was used as CS and the other was used as control. Preference indexes (PIs) for the rewarded odor before (white bars) and after (grey bars) training are shown as box and whisker diagrams. Odor preferences before and after training were compared by the WCX test. Odor preferences after training were compared between groups by the M-W test. The results of statistical comparisons are shown by asterisks (***P < 0.001, NS P > 0.05, adjusted by Holm’s method). The number of animals tested is shown at each data point.