These steps of selecting potential target nodes and choosing the single target node are repeated for a certain number of iteration which is user-defined. For our experiments, 20,000 iterations were run for each simulation. Results Corner preferences Wild-type Canton-S flies will linger in the corners of square arenas (Liu et al. 2007). It is possible that the corners represent increased thigmotactic surfaces that could drive the preference. Inhibitors,research,lifescience,medical We examined whether the corner preference would be increased by smaller angles using three parallelogram arenas

(Fig. 1). The smaller angled corners in these arenas bring the vertical surfaces closer, increasing their thigmotactic potential. The first arena had a 7.2 cm square base with four 90° corners. The base of the second arena had a 7.2-cm rhomboid base with alternate corners of 60° and 120°. The last parallelogram arena had a base with 7.2-cm sides Inhibitors,research,lifescience,medical and alternate corners of 30° and 150°. The time spent in a 1-cm2 area located at equal and opposite corners was determined for each arena. In the square arena, wild-type Canton-S spent roughly 25% of the time in each pair of opposite 90° corners with no significant differences between opposite corner pairs (Fig. 1; t = 0.116, P-value = 0.909, df = 23). Wild-type Canton-S spent Inhibitors,research,lifescience,medical significantly more time in the acute 60° corners than the obtuse 120° corners (Fig 1;

t = 2.265, P-value = 0.011, df = 23). Lastly, although Canton-S spent more time in the 30° corner than in the 150° corner, the difference was not significant (Fig. 1; t = 1.014, P-value = 0.316, df = 23). The time spent in corners was approximately the same for each of the three parallelogram arenas (~50%). The obtuse 120° Inhibitors,research,lifescience,medical and 150° corners retain an attractive quality for Drosophila since the flies spend considerable time within the proximity of these corners. The absence of a preference for 30° versus 150° corners is not consistent with smaller angles presenting a stronger thigmotactic attraction. Figure 1 Parallelogram-shaped Inhibitors,research,lifescience,medical arenas. Preference for corners is increased by smaller angles at the corners. There are no significant differences between the mean percentage of

time spent in 1-cm2 area located at opposite corners with equal angle of 90° … We next examined the antecedent for corner preference by placing four 90° corners, formed by two perpendicular intersecting walls extending 3 cm from the GSK-3 center point, in the center of the arena (Fig. 2A). If the corners are strongly preferred thigmotactic surfaces, the flies would leave the boundary and spend more time within the center of the arena. Although the internal corners significantly increased the amount of time in proximity to the center (t = –5.909, P-value < 0.0001, df = 31), the percentage of time spent (~6%) was far below that of external corners (~50%; Fig. 2B), suggesting the presumptive preference for the internal corners is less than the preference for the concave arena boundary.