The Power Law Distribution for Walking-Time Intervals Correlates with the Ellipsoid-Body in<i>Drosophila</i>

Martin, Jean‐René; Fauré, Philippe; Ernst, Roman

doi:10.3109/01677060109167377

Cited by 54 publications

(56 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are some examples in the literature showing that at least for ''simple'' organisms (e.g., bacteria, flagellates, fruit flies) motor-related neuronal configurations (43,44) and biochemical paths (45) could be responsible for a Lévy timing of reorientations (12,13,44,46). Empirical evidence of such fractal reorientation clocks at different levels of biological organization (e.g., neuronal, biochemical, physiological, behavioral) could explain, to some extent, the presence of Lévy flights and scale-free (i.e., fractal) properties in the movement patterns of some animals (e.g., refs.…”

Section: Discussionmentioning

confidence: 99%

Fractal reorientation clocks: Linking animal behavior to statistical patterns of search

Bartumeus

Levin

2008

Proc. Natl. Acad. Sci. U.S.A.

173

231

View full text Add to dashboard Cite

The movement ecology framework depicts animal movement as the result of the combined effects of internal and external constraints on animal navigation and motion capacities. Nevertheless, there are still fundamental problems to understand how these modulations take place and how they might be translated into observed statistical properties of animal trajectories. Of particular interest, here, is the general idea of intermittence in animal movement. Intermittent locomotion assumes that animal movement is, in essence, discrete. The existence of abrupt interruptions in an otherwise continuous flow of movement allows for the possibility of reorientations, that is, to break down previous directional memories of the trajectory. In this study, we explore the potential links between intermittent locomotion, reorientation behavior, and search efficiency. By means of simulations we show that the incorporation of Lé vy intermittence in an otherwise nonintermittent search strongly modifies encounter rates. The result is robust to different types of landscapes (i.e., target density and spatial distribution), and spatial dimensions (i.e., 2D, 3D). We propose that Lé vy intermittence may come from reorientation mechanisms capable of organizing directional persistence on time (i.e., fractal reorientation clocks), and we rationalize that the explicit distinction between scanning and reorientation mechanisms is essential to make accurate statistical inferences from animal search behavior. Finally, we provide a statistical tool to judge the existence of episodic and strong reorientation behaviors capable of modifying relevant properties of stochastic searches, ultimately controlling the chances of finding unknown located items.animal movement ͉ intermittent locomotion ͉ Lé vy walks ͉ random walks ͉ search strategies T he movement ecology framework explicitly recognizes animal movement as the result of a constant ''dialogue'' between environment (external factors) and animal internal states. This dialogue affects organisms' motion and/or navigation capacities to finally produce the actual movement (1). Beyond phenomenological descriptions of movement, the random paradigm (1) should seek to understand how interactions between the four components of the movement ecology framework (i.e., internal states, external forces, motion, and navigation capacities) might be translated into observed statistical patterns of movement (2, 3). In the present work, we suggest that a major advance in bridging the gap between animal behavior (mechanistic approach) and the statistical properties of search strategies involves a statistical reinterpretation of the idea of intermittent locomotion (4-6).The biological principle of intermittent locomotion assumes that animal behavior unavoidably produces observable punctuations in the movement (e.g., stops, strong changes in speed). Thus, the forces generating movement operate discontinuously, producing pauses and speeding patterns on the move. Intermittent locomotion (also known as stop-and-go movement, pau...

show abstract

Section: Discussionmentioning

confidence: 99%

Fractal reorientation clocks: Linking animal behavior to statistical patterns of search

Bartumeus

Levin

2008

Proc. Natl. Acad. Sci. U.S.A.

173

231

View full text Add to dashboard Cite

show abstract

“…Two P[Gal4] lines, P[Gal4]C35 and P[Gal4]C232, were used as controls. P[Gal4]C35 is expressed in the mushroom-bodies (14) and P[Gal4]C232 in the ring neurons of the ellipsoid-body (15)(16)(17), a substructure of the central complex. Expression of transformer in these strains did not lead to the feminization of start͞stop bouts (data not shown), suggesting that the mushroom-bodies and the ellipsoid-body are not involved in the control of this sexually dimorphic behavior.…”

Section: Number Of Start͞stop Bouts Is Sexually Dimorphicmentioning

confidence: 99%

Neuroendocrine control of a sexually dimorphic behavior by a few neurons of the pars intercerebralis in Drosophila

Belgacem

Martin

2002

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

In Drosophila, locomotor activity is sexually dimorphic and the brain area controlling this dimorphism has been mapped. The neurons of the pars intercerebralis (PI) have been suggested to participate in such differences between males and females. However, the precise physical nature of the dimorphism, the identity of the PI neurons involved, and the nature of the neuronal signal coding the dimorphism remain unknown. In this study, we used a video-tracking paradigm to characterize further the pattern of locomotor activity in Drosophila. We show that the number of activity͞inactivity periods (start͞stop bouts) is also sexually dimorphic, and that it can be genetically feminized in males. Moreover, the transplantation of PI neurons from a female, or of feminized PI neurons from a donor male into a receiver wild-type male is sufficient to induce the feminization of locomotor behavior, confirming that this tiny cluster of Ϸ10 neurons is directly responsible for the sexual dimorphism in locomotor activity. Finally, feeding males with fluvastatin, a juvenile hormone (JH) inhibitor, also led to start͞stop feminization, and this effect is reversible by the simultaneous application of methoprene, a JH analog, suggesting the existence of a neuroendocrine control, by JH, of such behavioral dimorphism. Invertebrates and vertebrates show sexually dimorphic behaviors, and it has been suggested that males and females differ in the brain structures controlling such behavioral differences (1-4). Such sex differences have often been used as a way of studying how brain structure contributes to brain function. However, although many sexually dimorphic neural structures have been described (2-4), very few studies have yet demonstrated the direct involvement of a brain structure in a sexually dimorphic behavior (5, 6) and still less a behavior expressed in a nonsexual context. We recently showed that Drosophila locomotor activity is sexually dimorphic (7) outside any sexual context. We could abolish this behavioral dimorphism and create males with a female-like activity profile by genetic manipulations (8). Briefly, we used a UAS-transformer transgene (UAS-tra; ref. 9), the feminizing action of which has been shown to be cell-autonomous (10-12), under the control of different brainspecific enhancer trap P[Gal4] lines. This first study suggested strongly that a few neurons located in the mid-anterior part of the pars intercerebralis (PI) might participate in the control of this sexually dimorphic behavior (8). However, because in this previous study the fly was observed in a small tube, the locomotor activity was indirectly quantified when the fly crossed an infra-red light-gate. As a result, the precise locomotor parameters that accounted for the sexual difference could not be elucidated. Furthermore, the involvement of the PI neurons was indirectly deduced on the basis of a genetic ablation, and the molecular mechanisms linking those few PI neurons to the sexually dimorphic behavior remained to be identified. In this study, we develo...

show abstract

“…iACT synapses were shown to be activated by electric shock to the abdomen (Yu et al 2004). In addition, we used driver c507, which specifically marks neurons of the ellipsoid body (Yang et al 2000), a brain area that is likely involved in regulating aspects of locomotion (Ilius et al 1994;Martin et al 1999Martin et al , 2001) and may be required for manifestation of the attenuated response. Finally, we used driver 78Y, which is expressed in particular structures of the central complex, the protocerebral bridge, ellipsoid body, and noduli (Martin et al 1999), neurons essential for locomotion and coordination in the fly (Strauss et al 1992;Martin et al 1999).…”

Section: Abrogation Of Mushroom Body Function Precipitates Rapid Attementioning

confidence: 99%

Protection from premature habituation requires functional mushroom bodies in Drosophila

Acevedo¹,

Froudarakis²,

Kanellopoulos³

et al. 2007

Learn. Mem.

View full text Add to dashboard Cite

Diminished responses to stimuli defined as habituation can serve as a gating mechanism for repetitive environmental cues with little predictive value and importance. We demonstrate that wild-type animals diminish their responses to electric shock stimuli with properties characteristic of short-and long-term habituation. We used spatially restricted abrogation of neurotransmission to identify brain areas involved in this behavioral response. We find that the mushroom bodies and, in particular, the ␣/␤ lobes appear to guard against habituating prematurely to repetitive electric shock stimuli. In addition to protection from premature habituation, the mushroom bodies are essential for spontaneous recovery and dishabituation. These results reveal a novel modulatory role of the mushroom bodies on responses to repetitive stimuli in agreement with and complementary to their established roles in olfactory learning and memory.

show abstract

The Power Law Distribution for Walking-Time Intervals Correlates with the Ellipsoid-Body inDrosophila

Cited by 54 publications

References 24 publications

Fractal reorientation clocks: Linking animal behavior to statistical patterns of search

Fractal reorientation clocks: Linking animal behavior to statistical patterns of search

Neuroendocrine control of a sexually dimorphic behavior by a few neurons of the pars intercerebralis in Drosophila

Protection from premature habituation requires functional mushroom bodies in Drosophila

Contact Info

Product

Resources

About