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Open-field arena boundary is a primary object of exploration for Drosophila.

Soibam B, Mann M, Liu L, Tran J, Lobaina M, Kang YY, Gunaratne GH, Pletcher S, Roman G - Brain Behav (2012)

Bottom Line: These experiments support the conclusion that the wall-following behavior of Drosophila is best characterized by a preference for the arena boundary, and not thigmotaxis or centrophobicity.Since the boundary preference could derive from highly linear trajectories, we further developed a simulation program to model the effects of turn angle on the boundary preference.Hence, low turn angled movement does not drive the boundary preference.

View Article: PubMed Central - PubMed

ABSTRACT
Drosophila adults, when placed into a novel open-field arena, initially exhibit an elevated level of activity followed by a reduced stable level of spontaneous activity and spend a majority of time near the arena edge, executing motions along the walls. In order to determine the environmental features that are responsible for the initial high activity and wall-following behavior exhibited during exploration, we examined wild-type and visually impaired mutants in arenas with different vertical surfaces. These experiments support the conclusion that the wall-following behavior of Drosophila is best characterized by a preference for the arena boundary, and not thigmotaxis or centrophobicity. In circular arenas, Drosophila mostly move in trajectories with low turn angles. Since the boundary preference could derive from highly linear trajectories, we further developed a simulation program to model the effects of turn angle on the boundary preference. In an hourglass-shaped arena with convex-angled walls that forced a straight versus wall-following choice, the simulation with constrained turn angles predicted general movement across a central gap, whereas Drosophila tend to follow the wall. Hence, low turn angled movement does not drive the boundary preference. Lastly, visually impaired Drosophila demonstrate a defect in attenuation of the elevated initial activity. Interestingly, the visually impaired w(1118) activity decay defect can be rescued by increasing the contrast of the arena's edge, suggesting that the activity decay relies on visual detection of the boundary. The arena boundary is, therefore, a primary object of exploration for Drosophila.

No MeSH data available.


Related in: MedlinePlus

Parallelogram-shaped 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° (Paired t -test: t = 0.116, P = 0.909) or between the 30° and 150° opposite corners (t = 1.014, P = 0.316). However, the flies spent significantly more time within the acute 60° corners than the 120° corners (t = 2.65, P = 0.011). For each arena n = 24.
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fig01: Parallelogram-shaped 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° (Paired t -test: t = 0.116, P = 0.909) or between the 30° and 150° opposite corners (t = 1.014, P = 0.316). However, the flies spent significantly more time within the acute 60° corners than the 120° corners (t = 2.65, P = 0.011). For each arena n = 24.

Mentions: 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. 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 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 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° 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.


Open-field arena boundary is a primary object of exploration for Drosophila.

Soibam B, Mann M, Liu L, Tran J, Lobaina M, Kang YY, Gunaratne GH, Pletcher S, Roman G - Brain Behav (2012)

Parallelogram-shaped 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° (Paired t -test: t = 0.116, P = 0.909) or between the 30° and 150° opposite corners (t = 1.014, P = 0.316). However, the flies spent significantly more time within the acute 60° corners than the 120° corners (t = 2.65, P = 0.011). For each arena n = 24.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3345355&req=5

fig01: Parallelogram-shaped 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° (Paired t -test: t = 0.116, P = 0.909) or between the 30° and 150° opposite corners (t = 1.014, P = 0.316). However, the flies spent significantly more time within the acute 60° corners than the 120° corners (t = 2.65, P = 0.011). For each arena n = 24.
Mentions: 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. 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 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 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° 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.

Bottom Line: These experiments support the conclusion that the wall-following behavior of Drosophila is best characterized by a preference for the arena boundary, and not thigmotaxis or centrophobicity.Since the boundary preference could derive from highly linear trajectories, we further developed a simulation program to model the effects of turn angle on the boundary preference.Hence, low turn angled movement does not drive the boundary preference.

View Article: PubMed Central - PubMed

ABSTRACT
Drosophila adults, when placed into a novel open-field arena, initially exhibit an elevated level of activity followed by a reduced stable level of spontaneous activity and spend a majority of time near the arena edge, executing motions along the walls. In order to determine the environmental features that are responsible for the initial high activity and wall-following behavior exhibited during exploration, we examined wild-type and visually impaired mutants in arenas with different vertical surfaces. These experiments support the conclusion that the wall-following behavior of Drosophila is best characterized by a preference for the arena boundary, and not thigmotaxis or centrophobicity. In circular arenas, Drosophila mostly move in trajectories with low turn angles. Since the boundary preference could derive from highly linear trajectories, we further developed a simulation program to model the effects of turn angle on the boundary preference. In an hourglass-shaped arena with convex-angled walls that forced a straight versus wall-following choice, the simulation with constrained turn angles predicted general movement across a central gap, whereas Drosophila tend to follow the wall. Hence, low turn angled movement does not drive the boundary preference. Lastly, visually impaired Drosophila demonstrate a defect in attenuation of the elevated initial activity. Interestingly, the visually impaired w(1118) activity decay defect can be rescued by increasing the contrast of the arena's edge, suggesting that the activity decay relies on visual detection of the boundary. The arena boundary is, therefore, a primary object of exploration for Drosophila.

No MeSH data available.


Related in: MedlinePlus