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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

Drosophila display few large-angled turns in circular open-field arenas. Turn angle was estimated in two separate zones within the arena. The central zone is the inner one-third portion of the arena and the edge zone is the outer one-third of the arena. (A). The distribution of the turn angle (histogram bin size of 3.6° was used) is shown with a 1-sec sampling interval. The most frequent turn angle for the edge and central zones are 12.6° and 3.6°, respectively. The turn angle distributions within the two zones are significantly different (χ2 = 43,412, P < 0.0001). (B). The median turn angle increases when sampling interval increases. For each sampling interval, the median turn angles between both zones were significantly different (sampling interval = 1 sec, t = 283.43, P < 0.0001). n = 173 Canton-S males.
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fig05: Drosophila display few large-angled turns in circular open-field arenas. Turn angle was estimated in two separate zones within the arena. The central zone is the inner one-third portion of the arena and the edge zone is the outer one-third of the arena. (A). The distribution of the turn angle (histogram bin size of 3.6° was used) is shown with a 1-sec sampling interval. The most frequent turn angle for the edge and central zones are 12.6° and 3.6°, respectively. The turn angle distributions within the two zones are significantly different (χ2 = 43,412, P < 0.0001). (B). The median turn angle increases when sampling interval increases. For each sampling interval, the median turn angles between both zones were significantly different (sampling interval = 1 sec, t = 283.43, P < 0.0001). n = 173 Canton-S males.

Mentions: Both in the edge and central zones, the median turn angle increased as the sampling interval increased (Fig. 5B). In the edge zone, the angle at which the turn angle distribution peaked increased from 3.6° to 12.6° (Supporting information and Fig. 5A) as the sampling interval increased from 0.1 to 1 sec. This indicates that different sampling intervals can give rise to different estimates of turn angles. However, for all of the 10 sampling intervals considered, the peaks of the distributions occur at small turn angles (maximum of 12.6°), which shows that flies prefer to execute small turn angles both in the edge and central zone. Irrespective of the sampling interval, the distribution of turn angle and the median turn angle in the edge zone and central zone were significantly different (Supporting information). This indicates that flies displayed different turn angle behavior in edge and central zone. The dissimilarity is most likely because the movement along the edge is shaped by the curvature of the circular edge. To examine this possibility, the turn angles were calculated for all the move lengths (ranging from 1 to 3 cm) of the fly in the edge zone. The computed turn angles were compared against the corresponding expected turn angles along the curvature of the arena. There was no significant difference between the observed and expected turn angles in the edge zone, which strongly suggests that wall-following behavior affects turning behavior (Supporting information).


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)

Drosophila display few large-angled turns in circular open-field arenas. Turn angle was estimated in two separate zones within the arena. The central zone is the inner one-third portion of the arena and the edge zone is the outer one-third of the arena. (A). The distribution of the turn angle (histogram bin size of 3.6° was used) is shown with a 1-sec sampling interval. The most frequent turn angle for the edge and central zones are 12.6° and 3.6°, respectively. The turn angle distributions within the two zones are significantly different (χ2 = 43,412, P < 0.0001). (B). The median turn angle increases when sampling interval increases. For each sampling interval, the median turn angles between both zones were significantly different (sampling interval = 1 sec, t = 283.43, P < 0.0001). n = 173 Canton-S males.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3345355&req=5

fig05: Drosophila display few large-angled turns in circular open-field arenas. Turn angle was estimated in two separate zones within the arena. The central zone is the inner one-third portion of the arena and the edge zone is the outer one-third of the arena. (A). The distribution of the turn angle (histogram bin size of 3.6° was used) is shown with a 1-sec sampling interval. The most frequent turn angle for the edge and central zones are 12.6° and 3.6°, respectively. The turn angle distributions within the two zones are significantly different (χ2 = 43,412, P < 0.0001). (B). The median turn angle increases when sampling interval increases. For each sampling interval, the median turn angles between both zones were significantly different (sampling interval = 1 sec, t = 283.43, P < 0.0001). n = 173 Canton-S males.
Mentions: Both in the edge and central zones, the median turn angle increased as the sampling interval increased (Fig. 5B). In the edge zone, the angle at which the turn angle distribution peaked increased from 3.6° to 12.6° (Supporting information and Fig. 5A) as the sampling interval increased from 0.1 to 1 sec. This indicates that different sampling intervals can give rise to different estimates of turn angles. However, for all of the 10 sampling intervals considered, the peaks of the distributions occur at small turn angles (maximum of 12.6°), which shows that flies prefer to execute small turn angles both in the edge and central zone. Irrespective of the sampling interval, the distribution of turn angle and the median turn angle in the edge zone and central zone were significantly different (Supporting information). This indicates that flies displayed different turn angle behavior in edge and central zone. The dissimilarity is most likely because the movement along the edge is shaped by the curvature of the circular edge. To examine this possibility, the turn angles were calculated for all the move lengths (ranging from 1 to 3 cm) of the fly in the edge zone. The computed turn angles were compared against the corresponding expected turn angles along the curvature of the arena. There was no significant difference between the observed and expected turn angles in the edge zone, which strongly suggests that wall-following behavior affects turning behavior (Supporting information).

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