Limits...
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

Modeling the effect of turn angle on a fly's position within the arenas. Each data point is the average of 20 simulations ± SEM. (A). Within a circular arena, there is a strong effect of limiting the fly's field of motion (FoM; equals twice the turn angle) on the percentage of time spent in the edge zone (outer one-third) of the arena. A simulated fly that can only move 10° either right or left is largely stuck in the edge zone; while a fly capable of 180° turns spend one-third of its time in each of the three concentric zones. The magenta lines indicate the percentage of time Canton-S spent experimentally in the edge zone (Fig 2; 89.9%), which corresponds to ∼24° FoM. (B). The percentage of time in a centrally located 2-cm2 zone was determined for both the inner cross-arena and a control open-field arena. The time Canton-S spent in this zone experimentally (Fig 2B) is indicated in yellow for the inner cross-arena and cyan for the control open field. Both of these measures correspond to ∼30°FoM. (C). In an hourglass-shaped arena, the numbers of vertical transitions (VTs) and horizontal transitions (HTs) across a central chasm were determined. A VT index is defined as (number of vertical transitions– number of horizontal transitions)/total number of transitions.
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fig06: Modeling the effect of turn angle on a fly's position within the arenas. Each data point is the average of 20 simulations ± SEM. (A). Within a circular arena, there is a strong effect of limiting the fly's field of motion (FoM; equals twice the turn angle) on the percentage of time spent in the edge zone (outer one-third) of the arena. A simulated fly that can only move 10° either right or left is largely stuck in the edge zone; while a fly capable of 180° turns spend one-third of its time in each of the three concentric zones. The magenta lines indicate the percentage of time Canton-S spent experimentally in the edge zone (Fig 2; 89.9%), which corresponds to ∼24° FoM. (B). The percentage of time in a centrally located 2-cm2 zone was determined for both the inner cross-arena and a control open-field arena. The time Canton-S spent in this zone experimentally (Fig 2B) is indicated in yellow for the inner cross-arena and cyan for the control open field. Both of these measures correspond to ∼30°FoM. (C). In an hourglass-shaped arena, the numbers of vertical transitions (VTs) and horizontal transitions (HTs) across a central chasm were determined. A VT index is defined as (number of vertical transitions– number of horizontal transitions)/total number of transitions.

Mentions: To test if the potential tiny gaps at the meeting of the ceiling and wall in previous arenas were responsible for boundary preference in previous arenas, a doughnut ceiling arena (Figure not shown) was used. A ceiling with a 2.5-cm diameter hole at the center was firmly affixed to the walls of the arena. A loose lid like the previous circular arena was laid on the top of the doughnut arena to create potential gaps at the edge of central zone. Even in the arena with a doughnut ceiling, flies spent the most amount of time near the edge (Fig. 6B; edge zone: 84.89 ±3.78%, middle zone: 13.98 ± 3.73%, central zone: 0.96 ± 0.26%). A robust boundary preference was retained even in the doughnut ceiling arena.


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)

Modeling the effect of turn angle on a fly's position within the arenas. Each data point is the average of 20 simulations ± SEM. (A). Within a circular arena, there is a strong effect of limiting the fly's field of motion (FoM; equals twice the turn angle) on the percentage of time spent in the edge zone (outer one-third) of the arena. A simulated fly that can only move 10° either right or left is largely stuck in the edge zone; while a fly capable of 180° turns spend one-third of its time in each of the three concentric zones. The magenta lines indicate the percentage of time Canton-S spent experimentally in the edge zone (Fig 2; 89.9%), which corresponds to ∼24° FoM. (B). The percentage of time in a centrally located 2-cm2 zone was determined for both the inner cross-arena and a control open-field arena. The time Canton-S spent in this zone experimentally (Fig 2B) is indicated in yellow for the inner cross-arena and cyan for the control open field. Both of these measures correspond to ∼30°FoM. (C). In an hourglass-shaped arena, the numbers of vertical transitions (VTs) and horizontal transitions (HTs) across a central chasm were determined. A VT index is defined as (number of vertical transitions– number of horizontal transitions)/total number of transitions.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3345355&req=5

fig06: Modeling the effect of turn angle on a fly's position within the arenas. Each data point is the average of 20 simulations ± SEM. (A). Within a circular arena, there is a strong effect of limiting the fly's field of motion (FoM; equals twice the turn angle) on the percentage of time spent in the edge zone (outer one-third) of the arena. A simulated fly that can only move 10° either right or left is largely stuck in the edge zone; while a fly capable of 180° turns spend one-third of its time in each of the three concentric zones. The magenta lines indicate the percentage of time Canton-S spent experimentally in the edge zone (Fig 2; 89.9%), which corresponds to ∼24° FoM. (B). The percentage of time in a centrally located 2-cm2 zone was determined for both the inner cross-arena and a control open-field arena. The time Canton-S spent in this zone experimentally (Fig 2B) is indicated in yellow for the inner cross-arena and cyan for the control open field. Both of these measures correspond to ∼30°FoM. (C). In an hourglass-shaped arena, the numbers of vertical transitions (VTs) and horizontal transitions (HTs) across a central chasm were determined. A VT index is defined as (number of vertical transitions– number of horizontal transitions)/total number of transitions.
Mentions: To test if the potential tiny gaps at the meeting of the ceiling and wall in previous arenas were responsible for boundary preference in previous arenas, a doughnut ceiling arena (Figure not shown) was used. A ceiling with a 2.5-cm diameter hole at the center was firmly affixed to the walls of the arena. A loose lid like the previous circular arena was laid on the top of the doughnut arena to create potential gaps at the edge of central zone. Even in the arena with a doughnut ceiling, flies spent the most amount of time near the edge (Fig. 6B; edge zone: 84.89 ±3.78%, middle zone: 13.98 ± 3.73%, central zone: 0.96 ± 0.26%). A robust boundary preference was retained even in the doughnut ceiling arena.

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