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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

Arena boundary and not vertical surfaces are preferred. (A). An arena was constructed with internal concentric walls. For analysis, the arena was subdivided into four zones. (B). The behavior of flies was examined in the concentric circle arena having either transparent or opaque walls. When the walls were clear, wild-type Canton-S spent 92.7% of the time in the outermost zone. This is significantly more time than when the walls were opaque (65.2%, P <0.0001). The neutral expectation is derived from the percent area of each zone. n = 32 for each experiment.
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fig04: Arena boundary and not vertical surfaces are preferred. (A). An arena was constructed with internal concentric walls. For analysis, the arena was subdivided into four zones. (B). The behavior of flies was examined in the concentric circle arena having either transparent or opaque walls. When the walls were clear, wild-type Canton-S spent 92.7% of the time in the outermost zone. This is significantly more time than when the walls were opaque (65.2%, P <0.0001). The neutral expectation is derived from the percent area of each zone. n = 32 for each experiment.

Mentions: In most open-field arenas, the boundary is both the furthest extent of the explorable territory and the only available vertical surface; either of these two features could be responsible for attracting the flies. In the internal corner arena, the flies did attend the internal surfaces, but to a significantly lesser degree than the curved boundary, leaving open the possibility that curved surfaces are generally preferred to straight walls. To address this concern, we have examined the behavior of wild-type Drosophila in arenas having equally spaced internal concentric circular walls (Fig. 4A). The walls in this arena subdivide the space into four concentric zones with different areas. The inner zones also offer walls of greater curvatures, and more proximate thigmotaxis. In this concentric circle arena, with either clear or opaque walls, the flies displayed a significant preference for the outermost zone (Fig. 4B) compared to the expected value based on neutral space (clear walls: χ2 = 91.95, P-value < 0.0001, df = 3; opaque walls: χ2 = 17.2, P-value = 0.0006, df = 3). The neutral expectation is derived from the percent area of each zone (i.e., zone 1 accounts for 45.1% of the total arena area, resulting in an expected percentage of time in zone of 270.6 sec). When the walls were opaque, the flies did spend significantly less time in the outermost zone compared to the transparent walls (zone 1; P-value < 0.01), but still more than expected based on neutral space (χ2 = 17.2, P-value = 0.0006, df = 3). Therefore, the preference was for the arena boundary, and not simply vertical surfaces.


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)

Arena boundary and not vertical surfaces are preferred. (A). An arena was constructed with internal concentric walls. For analysis, the arena was subdivided into four zones. (B). The behavior of flies was examined in the concentric circle arena having either transparent or opaque walls. When the walls were clear, wild-type Canton-S spent 92.7% of the time in the outermost zone. This is significantly more time than when the walls were opaque (65.2%, P <0.0001). The neutral expectation is derived from the percent area of each zone. n = 32 for each experiment.
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Related In: Results  -  Collection

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fig04: Arena boundary and not vertical surfaces are preferred. (A). An arena was constructed with internal concentric walls. For analysis, the arena was subdivided into four zones. (B). The behavior of flies was examined in the concentric circle arena having either transparent or opaque walls. When the walls were clear, wild-type Canton-S spent 92.7% of the time in the outermost zone. This is significantly more time than when the walls were opaque (65.2%, P <0.0001). The neutral expectation is derived from the percent area of each zone. n = 32 for each experiment.
Mentions: In most open-field arenas, the boundary is both the furthest extent of the explorable territory and the only available vertical surface; either of these two features could be responsible for attracting the flies. In the internal corner arena, the flies did attend the internal surfaces, but to a significantly lesser degree than the curved boundary, leaving open the possibility that curved surfaces are generally preferred to straight walls. To address this concern, we have examined the behavior of wild-type Drosophila in arenas having equally spaced internal concentric circular walls (Fig. 4A). The walls in this arena subdivide the space into four concentric zones with different areas. The inner zones also offer walls of greater curvatures, and more proximate thigmotaxis. In this concentric circle arena, with either clear or opaque walls, the flies displayed a significant preference for the outermost zone (Fig. 4B) compared to the expected value based on neutral space (clear walls: χ2 = 91.95, P-value < 0.0001, df = 3; opaque walls: χ2 = 17.2, P-value = 0.0006, df = 3). The neutral expectation is derived from the percent area of each zone (i.e., zone 1 accounts for 45.1% of the total arena area, resulting in an expected percentage of time in zone of 270.6 sec). When the walls were opaque, the flies did spend significantly less time in the outermost zone compared to the transparent walls (zone 1; P-value < 0.01), but still more than expected based on neutral space (χ2 = 17.2, P-value = 0.0006, df = 3). Therefore, the preference was for the arena boundary, and not simply vertical surfaces.

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