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1.
J R Soc Interface ; 21(214): 20230737, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38689546

RESUMO

Patterns of collective escape of a bird flock from a predator are fascinating, but difficult to study under natural conditions because neither prey nor predator is under experimental control. We resolved this problem by using an artificial predator (RobotFalcon) resembling a peregrine falcon in morphology and behaviour. We imitated hunts by chasing flocks of corvids, gulls, starlings and lapwings with the RobotFalcon, and compared their patterns of collective escape to those when chased by a conventional drone and, in case of starlings, hunted by wild peregrine falcons. Active pursuit of flocks, rather than only flying nearby by either the RobotFalcon or the drone, made flocks collectively escape more often. The RobotFalcon elicited patterns of collective escape in flocks of all species more often than the drone. Attack altitude did not affect the frequency of collective escape. Starlings escaped collectively equally often when chased by the RobotFalcon or a wild peregrine falcon. Flocks of all species reacted most often by collective turns, second most often by compacting and third by splitting into subflocks. This study demonstrates the potential of an artificial aerial predator for studying the collective escape behaviour of free-living birds, opening exciting avenues in the empirical study of prey-predator interactions.


Assuntos
Reação de Fuga , Falconiformes , Robótica , Animais , Reação de Fuga/fisiologia , Falconiformes/fisiologia , Comportamento Predatório/fisiologia , Aves/fisiologia , Especificidade da Espécie
2.
J Exp Zool B Mol Dev Evol ; 342(5): 406-411, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38708813

RESUMO

Egg dehydration can kill terrestrial frog embryos, and this threat is increasing with climate change and deforestation. In several lineages that independently evolved terrestrial eggs, and retained aquatic tadpoles, embryos accelerate hatching to escape from drying eggs, entering the water earlier and less developed. However, the cues that stimulate drying-induced early hatching are unknown. Ammonia is a toxic, water-soluble metabolic waste that accumulates within eggs as embryos develop and concentrates as eggs dehydrate. Thus, increasing ammonia concentration may be a direct threat to embryos in drying eggs. We hypothesized that it could serve as a cue, stimulating embryos to hatch and escape. The embryos of red-eyed treefrogs, Agalychnis callidryas, hatch early to escape from many threats, including dehydration, and are known to use mechanosensory, hypoxia, and light cues. To test if they also use high ammonia as a cue to hatch, we exposed stage-matched pairs of hatching-competent, well-hydrated sibling embryos to ammonia and control solutions in shallow water baths and recorded their behavior. Control embryos remained unhatched while ammonia-exposed embryos showed a rapid, strong hatching response; 95% hatched, on average in under 15 min. This demonstrates that elevated ammonia can serve as a hatching cue for A. callidryas embryos. This finding is a key step in understanding the mechanisms that enable terrestrial frog embryos to escape from egg drying, opening new possibilities for integrative and comparative studies on this growing threat.


Assuntos
Amônia , Anuros , Sinais (Psicologia) , Embrião não Mamífero , Óvulo , Animais , Amônia/toxicidade , Anuros/embriologia , Anuros/fisiologia , Óvulo/fisiologia , Embrião não Mamífero/fisiologia , Desidratação , Reação de Fuga/fisiologia , Reação de Fuga/efeitos dos fármacos
3.
Behav Processes ; 219: 105057, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38788911

RESUMO

The nearest-neighbour distance is an important property of a group, as individuals can obtain environmental information more quickly and easily from nearby individuals. We examined whether distance to the nearest neighbour affected two components of escape behaviour - alert distance (AD) and flight initiation distance (FID) - in an urban population of hooded crows Corvus cornix, while controlling for confounding variables. We did not find evidence that AD and FID were influenced by the nearest neighbour distance. However, both AD and FID were negatively affected by feeding activity of individuals - focal crows alerted later and escaped at shorter distance if they were feeding during our approach. In addition, AD and FID were positively related to starting distance and grass coverage. The lack of evidence for the nearest neighbour effect on escape behaviour of crows may be due to: (1) disturbance by close neighbours that may impede antipredator behaviour of focal birds, (2) variable distribution of familiar, dominant or experienced individuals within a flock, and (3) dynamic change in position of the nearest neighbour during the potential predator approach.


Assuntos
Corvos , Reação de Fuga , Corvos/fisiologia , Animais , Reação de Fuga/fisiologia , Comportamento Animal/fisiologia , Masculino , Comportamento Alimentar/fisiologia , Feminino
4.
Biol Lett ; 20(5): 20240058, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38715463

RESUMO

Predation exerts a significant selection pressure on prey, shaping a multitude of traits that serve as antipredator defences. In turn, natural selection could favour combinations of antipredator defences with synergistic effects that enhance prey survival. An especially interesting antipredator defence is death feigning (DF), present in a wide variety of taxa and usually characterized by the prey lying motionless often along with defaecation, musking and autohaemorrhaging (AH). All these aspects of the DF display should work in conjunction with one another, intensifying the overall effect of the display and in turn facilitating quicker escape. To confirm this hypothesis, we tested 263 dice snakes (Natrix tessellata) directly in the field. We noted the occurrence of smearing faeces, musk and AH, and we measured the duration of DF, expecting to see a negative association between the occurrence of these behaviours and the duration of DF. Our results affirm our hypothesis: dice snakes that smeared themselves in musk and faeces prior to DF and had AH during DF spent significantly less time in DF. Our results highlight the functional integration of antipredator behaviours across different phases of predator-prey interactions, emphasizing the need for future research to prioritize studying the sequential display of behaviours.


Assuntos
Comportamento Predatório , Animais , Colubridae/fisiologia , Fezes , Reação de Fuga/fisiologia , Masculino
5.
J Exp Biol ; 227(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38690629

RESUMO

Identifying the kinematic and behavioral variables of prey that influence evasion from predator attacks remains challenging. To address this challenge, we have developed an automated escape system that responds quickly to an approaching predator and pulls the prey away from the predator rapidly, similar to real prey. Reaction distance, response latency, escape speed and other variables can be adjusted in the system. By repeatedly measuring the response latency and escape speed of the system, we demonstrated the system's ability to exhibit fast and rapid responses while maintaining consistency across successive trials. Using the live predatory fish species Coreoperca kawamebari, we show that escape speed and reaction distance significantly affect the outcome of predator-prey interactions. These findings indicate that the developed escape system is useful for identifying kinematic and behavioral features of prey that are critical for predator evasion, as well as for measuring the performance of predators.


Assuntos
Reação de Fuga , Comportamento Predatório , Animais , Reação de Fuga/fisiologia , Fenômenos Biomecânicos , Automação , Tempo de Reação/fisiologia
6.
Neuropharmacology ; 252: 109949, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38636726

RESUMO

Psychedelic compounds have potentially rapid, long-lasting anxiolytic, antidepressive and anti-inflammatory effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A receptor partial agonist, decreases stress-related behavior in male mice exposed to repeated social aggression. Additionally, we explored the likelihood that these behavioral changes are related to anti-inflammatory properties of [(R)-DOI]. Animals were subjected to the Stress Alternatives Model (SAM), an escapable social stress paradigm in which animals develop reactive coping strategies - remaining in the SAM arena (Stay) with a social aggressor, or dynamically initiated stress coping strategies that involve utilizing the escape holes (Escape) to avoid aggression. Mice expressing these behavioral phenotypes display behaviors like those in other social aggression models that separate animals into stress-vulnerable (as for Stay) or stress-resilient (as for Escape) groups, which have been shown to have distinct inflammatory responses to social stress. These results show that Stay animals have heightened cytokine gene expression, and both Stay and Escape mice exhibit plasma and neural concentrations of the inflammatory cytokine tumor necrosis factor-α (TNFα) compared to unstressed control mice. Additionally, these results suggest that a single administration of (R)-DOI to Stay animals in low doses, can increase stress coping strategies such as increasing attention to the escape route, promoting escape behavior, and reducing freezing during socially aggressive interaction in the SAM. Lower single doses of (R)-DOI, in addition to shifting behavior to suggest anxiolytic effects, also concomitantly reduce plasma and limbic brain levels of the inflammatory cytokine TNFα.


Assuntos
Adaptação Psicológica , Agressão , Anfetaminas , Alucinógenos , Estresse Psicológico , Animais , Masculino , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Alucinógenos/administração & dosagem , Alucinógenos/farmacologia , Adaptação Psicológica/efeitos dos fármacos , Adaptação Psicológica/fisiologia , Camundongos , Agressão/efeitos dos fármacos , Agressão/fisiologia , Anfetaminas/farmacologia , Anfetaminas/administração & dosagem , Camundongos Endogâmicos C57BL , Fator de Necrose Tumoral alfa/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Agonistas do Receptor 5-HT2 de Serotonina/administração & dosagem , Reação de Fuga/efeitos dos fármacos , Capacidades de Enfrentamento
7.
J Exp Biol ; 227(9)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38634142

RESUMO

The ability of predators to adopt hunting tactics that minimise escape reactions from prey is crucial for efficient foraging, and depends on detection capabilities and locomotor performance of both predators and prey. Here, we investigated the efficiency of a small pinniped, the Antarctic fur seal (Arctocephalus gazella) at exploiting their small prey by describing for the first time their fine-scale predator-prey interactions. We compared these with those from another diving predator, the southern elephant seal (Mirounga leonina) that forage on the same prey type. We used data recorded by a newly developed sonar tag that combines active acoustics with ultrahigh-resolution movement sensors to study simultaneously the fine-scale behaviour of both Antarctic fur seals and prey during predator-prey interactions in more than 1200 prey capture events for eight female Antarctic fur seals. Our results showed that Antarctic fur seals and their prey detect each other at the same time, i.e. 1-2 s before the strike, forcing Antarctic fur seals to display reactive fast-moving chases to capture their prey. In contrast, southern elephant seals detect their prey up to 10 s before the strike, allowing them to approach their prey stealthily without triggering an escape reaction. The active hunting tactics used by Antarctic fur seals is probably very energy consuming compared with the stalking tactics used by southern elephant seals but might be compensated for by the consumption of faster-moving larger prey. We suggest that differences in manoeuvrability, locomotor performance and detection capacities and in pace of life between Antarctic fur seals and southern elephant seals might explain these differences in hunting styles.


Assuntos
Otárias , Comportamento Predatório , Focas Verdadeiras , Animais , Otárias/fisiologia , Feminino , Focas Verdadeiras/fisiologia , Regiões Antárticas , Acústica , Reação de Fuga/fisiologia
8.
Curr Opin Insect Sci ; 63: 101180, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38432555

RESUMO

Detecting looming motion directly towards the insect is vital to its survival. Looming detection in two insects, flies and locusts, is described and contrasted. Pathways using looming detectors to trigger action and their topographical layout in the brain is explored in relation to facilitating behavioural selection. Similar visual stimuli, such as looming motion, are processed by nearby glomeruli in the brain. Insect-inspired looming motion detectors are combined to detect and avoid collision in different scenarios by robots, vehicles and unmanned aerial vehicle (UAV)s.


Assuntos
Reação de Fuga , Animais , Percepção de Movimento , Dípteros/fisiologia , Gafanhotos/fisiologia , Insetos/fisiologia , Visão Ocular
9.
J Neurosci Methods ; 405: 110099, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38417713

RESUMO

BACKGROUND: Escape is one of the most essential behaviors for an animal's survival because it could be a matter of life and death. Much of our current understanding of the neural mechanisms underlying escape is derived from the looming paradigm, which mimics a diving aerial predator. Yet, the idea of the looming paradigm does not account for all types of threats like lions hunting antelopes or cats stalking mice. Escape responses to such terrestrial threats may require different strategies and neural mechanisms. NEW METHODS: Here, we developed a real-time interactive platform to study escape behavior to terrestrial threats in mice. A closed-loop controlled robot was magnetically pulled to mimic a terrestrial threat that chases a mouse. By using strong magnets and high-precision servo motors, the robot is capable of moving precisely with a high spatial-temporal resolution. Different algorithms can be used to achieve single approach or persistent approach. RESULTS: Animal experiments showed that mice exhibited consistent escape behavior when exposed to an approaching robotic predator. When presented with a persistently approaching predator, the mice were able to rapidly adapt their behavior, as evidenced by a decrease in startle responses and changes in movement patterns. COMPARISON WITH EXISTING METHODS: In comparison to existing methods for studying escape behavior, such as the looming paradigm, this approach is more suitable for investigating animal behavior in response to sustained threats. CONCLUSION: In conclusion, we have developed a flexible platform to study escape behavior to terrestrial threats in mice.


Assuntos
Reação de Fuga , Roedores , Animais , Camundongos , Reação de Fuga/fisiologia , Comportamento Animal , Comportamento Predatório/fisiologia
10.
Sci Rep ; 14(1): 1078, 2024 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-38212397

RESUMO

Escaping a predator is one of the keys to success for any living creature. The performance of adults (males, females, and ovigerous females) of the cyclopoid copepod Oithona davisae exposed to an electrical stimulus is analysed as a function of temperature by measuring characteristic parameters associated with the escape movement (distance covered, duration of the appendage movement, mean and maximum escape speeds, Reynolds number). In addition, as a proxy for the efficiency of the motion, the Strouhal number was calculated. The escape performance showed temperature-dependent relationships within each adult state, as well as differences between sexes; additionally, changes owing to the presence of the egg sac were recorded in females. In a broader perspective, the results collected reveal the occurrence of different behavioural adaptations in males and females, adding to the comprehension of the mechanisms by which O. davisae interacts with its environment and shedding new light on the in situ population dynamics of this species.


Assuntos
Copépodes , Reação de Fuga , Animais , Feminino , Masculino , Copépodes/fisiologia
11.
Proc Natl Acad Sci U S A ; 120(51): e2303641120, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38096410

RESUMO

When threatened by dangerous or harmful stimuli, animals engage in diverse forms of rapid escape behaviors. In Drosophila larvae, one type of escape response involves C-shaped bending and lateral rolling followed by rapid forward crawling. The sensory circuitry that promotes larval escape has been extensively characterized; however, the motor programs underlying rolling are unknown. Here, we characterize the neuromuscular basis of rolling escape behavior. We used high-speed, volumetric, Swept Confocally Aligned Planar Excitation (SCAPE) microscopy to image muscle activity during larval rolling. Unlike sequential peristaltic muscle contractions that progress from segment to segment during forward and backward crawling, muscle activity progresses circumferentially during bending and rolling escape behavior. We propose that progression of muscular contraction around the larva's circumference results in a transient misalignment between weight and the ground support forces, which generates a torque that induces stabilizing body rotation. Therefore, successive cycles of slight misalignment followed by reactive aligning rotation lead to continuous rolling motion. Supporting our biomechanical model, we found that disrupting the activity of muscle groups undergoing circumferential contraction progression leads to rolling defects. We use EM connectome data to identify premotor to motor connectivity patterns that could drive rolling behavior and perform neural silencing approaches to demonstrate the crucial role of a group of glutamatergic premotor neurons in rolling. Our data reveal body-wide muscle activity patterns and putative premotor circuit organization for execution of the rolling escape response.


Assuntos
Drosophila , Neurônios , Animais , Drosophila/fisiologia , Neurônios/fisiologia , Larva/fisiologia , Reação de Fuga/fisiologia , Contração Muscular , Drosophila melanogaster/fisiologia
12.
PeerJ ; 11: e15812, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37671364

RESUMO

Captive breeding programs are an important pillar in biodiversity conservation, aiming to prevent the extinction of threatened species. However, the establishment of self-sustaining populations in the wild through the release of captive-bred animals is often hampered by a high mortality upon release. In this study, we investigated how a 2-week confinement period within a large field enclosure affected the anti-predator behaviour of 'naive' captive-bred hamsters and how potential modifications persisted over time. During three consecutive tests, hamsters were confronted with a moving predator model (a red fox mount, Vulpes vulpes) and their behaviour was filmed. After the initial round of confrontation with the predator model, one group of hamsters (field group) was released into a field enclosure protected from predators, while the other group (control) remained in their individual laboratory cages. After 2 weeks, hamsters from the field group were recaptured and individuals of both groups underwent a second confrontation test. A total of 1 month after their return from the field enclosure, field hamsters were subjected to a last confrontation test. Video analysis, investigating four behavioural variables, revealed that field hamsters significantly modified their behavioural response following the 2 weeks confinement in the enclosure, while this was not the case for control hamsters. In addition, most behavioural modifications in field hamsters persisted over 1 month, while others started to revert. We suggest that an appropriate pre-release period inside a field enclosure will enable naive (captive-bred) hamsters to develop an adequate anti-predator behaviour that will increase their immediate survival probability upon release into the wild. We believe that such measure will be of great importance for hamster conservation programs.


Assuntos
Comportamento Animal , Conservação dos Recursos Naturais , Cricetinae , Reação de Fuga , Abrigo para Animais , Reforço Psicológico , Animais , Raposas , Comportamento Animal/fisiologia , Reação de Fuga/fisiologia , Conservação dos Recursos Naturais/métodos
13.
Nature ; 620(7974): 595-599, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37558871

RESUMO

Migratory songbirds have the remarkable ability to extract directional information from the Earth's magnetic field1,2. The exact mechanism of this light-dependent magnetic compass sense, however, is not fully understood. The most promising hypothesis focuses on the quantum spin dynamics of transient radical pairs formed in cryptochrome proteins in the retina3-5. Frustratingly, much of the supporting evidence for this theory is circumstantial, largely because of the extreme challenges posed by genetic modification of wild birds. Drosophila has therefore been recruited as a model organism, and several influential reports of cryptochrome-mediated magnetic field effects on fly behaviour have been widely interpreted as support for a radical pair-based mechanism in birds6-23. Here we report the results of an extensive study testing magnetic field effects on 97,658 flies moving in a two-arm maze and on 10,960 flies performing the spontaneous escape behaviour known as negative geotaxis. Under meticulously controlled conditions and with vast sample sizes, we have been unable to find evidence for magnetically sensitive behaviour in Drosophila. Moreover, after reassessment of the statistical approaches and sample sizes used in the studies that we tried to replicate, we suggest that many-if not all-of the original results were false positives. Our findings therefore cast considerable doubt on the existence of magnetic sensing in Drosophila and thus strongly suggest that night-migratory songbirds remain the organism of choice for elucidating the mechanism of light-dependent magnetoreception.


Assuntos
Drosophila melanogaster , Campos Magnéticos , Resultados Negativos , Animais , Migração Animal , Criptocromos/metabolismo , Aves Canoras/fisiologia , Drosophila melanogaster/fisiologia , Modelos Animais , Reação de Fuga , Aprendizagem em Labirinto , Tamanho da Amostra , Luz
14.
J Exp Biol ; 226(14)2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37493068

RESUMO

Work carried out since the late 1970s has provided key insights into the comparative biomechanics, kinematics, behaviour and neurobiology of fish escape responses. An escape response is an ecologically important behaviour used by fishes to evade predation and aggression via rapid swimming movements. With environmental change expected to affect the physiology and biomechanics of aquatic ectotherms, there is a growing interest in understanding how environmental stressors affect the swimming performance and behaviour of fishes during escape responses, particularly in the context of predator-prey interactions. As the study of fish swimming continues to expand, there have been repeated calls to standardise experiments and reporting practices to facilitate integrative and comparative studies. Here, we provide a set of practical guidelines for conducting, analysing and reporting experiments on escape responses in fish, including a reporting checklist to assist authors undertaking these experiments. These resources will facilitate executing and reporting escape response experiments in a rigorous and transparent fashion, helping to advance the study of fish swimming in an era of rapid environmental change.


Assuntos
Peixes , Natação , Animais , Fenômenos Biomecânicos , Peixes/fisiologia , Natação/fisiologia , Comportamento Predatório , Agressão , Reação de Fuga/fisiologia
15.
PLoS One ; 18(6): e0274437, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37347773

RESUMO

We designed a behavioral task called One-Trial Trace Escape Reaction (OTTER), in which rats incidentally associate two temporally discontinuous stimuli: a neutral acoustic cue (CS) with an aversive stimulus (US) which occurs two seconds later (CS-2s-US sequence). Rats are first habituated to two similar environmental contexts (A and B), each consisting of an interconnected dark and light chamber. Next, rats experience the CS-2s-US sequence in the dark chamber of one of the contexts (either A or B); the US is terminated immediately after a rat escapes into the light chamber. The CS-2s-US sequence is presented only once to ensure the incidental acquisition of the association. The recall is tested 24 h later when rats are presented with only the CS in the alternate context (B or A), and their behavioral response is observed. Our results show that 59% of the rats responded to the CS by escaping to the light chamber, although they experienced only one CS-2s-US pairing. The OTTER task offers a flexible high throughput tool to study memory acquired incidentally after a single experience. Incidental one-trial acquisition of association between temporally discontinuous events may be one of the essential components of episodic memory formation.


Assuntos
Lontras , Ratos , Animais , Medo/fisiologia , Rememoração Mental , Reação de Fuga
16.
Behav Brain Res ; 449: 114462, 2023 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-37121276

RESUMO

Previously we showed that Deep Brain Stimulation (DBS) of the dorsal region (DRD) and of the lateral wings of the dorsal raphe (lwDR) respectively decreases anxiety and panic-like responses in the elevated T-maze (ETM). This study investigates neurobiological alterations which might respond for these behavioral effects. Male Wistar rats were submitted to high-frequency stimulation (100 µA, 100 Hz) of the DRD or of the lwDR for 1 h, and subsequently tested in the avoidance or escape tasks of the ETM. Since serotonin (5-HT) reuptake inhibitors are first line pharmacological treatment for anxiety disorders, we also tested the effects of chronic fluoxetine administration (10 mg/kg, IP, 21 days) on a separate group of rats. An open field was used for locomotor activity assessment. Additionally, we evaluated c-Fos immunoreactivity (Fos-ir) in serotonergic cells of the dorsal raphe (DR). Results showed that DBS of the DRD decreases avoidance reactions, an anxiolytic-like effect, without altering escape or locomotor activity. Both fluoxetine and DBS of the lwDR decreased escape responses in the ETM, a panicolytic-like effect, without altering avoidance measurements or locomotor activity. While DBS of the DRD decreased double immunostaining in the DRD, DBS of the lwDR increased Fos-ir and double immunostaining in the DRD and lwDR. Fluoxetine also increased double immunostaining in the lwDR and in the DRV but decreased it in the DRD. These results suggest that both the anxiolytic and panicolytic-like effects of DBS and fluoxetine are related to 5-HT modulation in different subnuclei of the DR.


Assuntos
Ansiolíticos , Estimulação Encefálica Profunda , Ratos , Masculino , Animais , Ansiolíticos/farmacologia , Núcleo Dorsal da Rafe , Serotonina/farmacologia , Fluoxetina/farmacologia , Ratos Wistar , Reação de Fuga/fisiologia , Ansiedade/tratamento farmacológico
17.
J Exp Biol ; 226(8)2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-37066993

RESUMO

Spatially invariant feature detection is a property of many visual systems that rely on visual information provided by two eyes. However, how information across both eyes is integrated for invariant feature detection is not fully understood. Here, we investigated spatial invariance of looming responses in descending neurons (DNs) of Drosophila melanogaster. We found that multiple looming responsive DNs integrate looming information across both eyes, even though their dendrites are restricted to a single visual hemisphere. One DN, the giant fiber (GF), responds invariantly to looming stimuli across tested azimuthal locations. We confirmed visual information propagates to the GF from the contralateral eye, through an unidentified pathway, and demonstrated that the absence of this pathway alters GF responses to looming stimuli presented to the ipsilateral eye. Our data highlight a role for bilateral visual integration in generating consistent, looming-evoked escape responses that are robust across different stimulus locations and parameters.


Assuntos
Drosophila melanogaster , Drosophila , Animais , Drosophila melanogaster/fisiologia , Neurônios/fisiologia , Estimulação Luminosa , Reação de Fuga/fisiologia
18.
Elife ; 122023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36916795

RESUMO

Larval zebrafish that are exposed repeatedly to dark looming stimuli will quickly habituate to these aversive signals and cease to respond with their stereotypical escape swims. A dark looming stimulus can be separated into two independent components: one that is characterized by an overall spatial expansion, where overall luminance is maintained at the same level, and a second, that represents an overall dimming within the whole visual field in the absence of any motion energy. Using specific stimulation patterns that isolate these independent components, we first extracted the behavioral algorithms that dictate how these separate information channels interact with each other and across the two eyes during the habituation process. Concurrent brain wide imaging experiments then permitted the construction of circuit models that suggest the existence of two separate neural pathways. The first is a looming channel which responds specifically to expanding edges presented to the contralateral eye and relays that information to the brain stem escape network to generate directed escapes. The second is a dimming-specific channel that could be either monocular or binocularly responsive, and that appears to specifically inhibit escape response when activated. We propose that this second channel is under strong contextual modulation and that it is primarily responsible for the incremental silencing of successive dark looming-evoked escapes.


Assuntos
Reação de Fuga , Peixe-Zebra , Animais , Peixe-Zebra/fisiologia , Reação de Fuga/fisiologia , Larva/fisiologia , Habituação Psicofisiológica , Encéfalo/fisiologia
19.
Elife ; 122023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36790147

RESUMO

The escape trajectory (ET) of prey - measured as the angle relative to the predator's approach path - plays a major role in avoiding predation. Previous geometric models predict a single ET; however, many species show highly variable ETs with multiple preferred directions. Although such a high ET variability may confer unpredictability to avoid predation, the reasons why animals prefer specific multiple ETs remain unclear. Here, we constructed a novel geometric model that incorporates the time required for prey to turn and the predator's position at the end of its attack. The optimal ET was determined by maximizing the time difference of arrival at the edge of the safety zone between the prey and predator. By fitting the model to the experimental data of fish Pagrus major, we show that the model can clearly explain the observed multiple preferred ETs. By changing the parameters of the same model within a realistic range, we were able to produce various patterns of ETs empirically observed in other species (e.g., insects and frogs): a single preferred ET and multiple preferred ETs at small (20-50°) and large (150-180°) angles from the predator. Our results open new avenues of investigation for understanding how animals choose their ETs from behavioral and neurosensory perspectives.


When a prey spots a predator about to pounce, it turns swiftly and accelerates away to avoid being captured. The initial direction the prey chooses to take ­ known as its escape trajectory ­ can greatly impact their chance of survival. Previous models were able to predict the optimal direction an animal should take to maximize its chances of evading the predator. However, experimental data suggest that prey actually tend to escape via multiple specific directions, although why animals use this approach has not been clarified. To investigate this puzzle, Kawabata et al. built a new mathematical model that better represents how prey and predators interact with one another in the real world. Unlike past models, Kawabata et al. incorporated the time required for prey to change direction and only allowed the predators to move toward the prey for a limited distance. By including these two factors, they were able to reproduce the escape trajectories of real animals, including a species of fish, as well as species from other taxa such as frogs and insects. The new model suggests that prey escape along one of two directions: either by moving directly away from the predator in order to outrun its attack, or by dodging sideways to avoid being captured. Which strategy the prey chooses has some elements of unpredictability, which makes it more difficult for predators to adjust their capturing method. These findings shed light on why escaping in multiple specific directions makes prey harder to catch. The model could also be extended to test the escape trajectories of a wider variety of predator and prey species, which may avoid capture via different routes. This could help researchers better understand how predators and prey interact with one another. The findings could also reveal how sensory information (such as sound and sight) associated with the threat of an approaching predator is processed and stimulates the muscle activity required to escape in multiple different directions.


Assuntos
Reação de Fuga , Comportamento Predatório , Animais , Anuros
20.
Proc Natl Acad Sci U S A ; 120(7): e2218909120, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36757892

RESUMO

An effective evasion strategy allows prey to survive encounters with predators. Prey are generally thought to escape in a direction that is either random or serves to maximize the minimum distance from the predator. Here, we introduce a comprehensive approach to determine the most likely evasion strategy among multiple hypotheses and the role of biomechanical constraints on the escape response of prey fish. Through a consideration of six strategies with sensorimotor noise and previous kinematic measurements, our analysis shows that zebrafish larvae generally escape in a direction orthogonal to the predator's heading. By sensing only the predator's heading, this orthogonal strategy maximizes the distance from fast-moving predators, and, when operating within the biomechanical constraints of the escape response, it provides the best predictions of prey behavior among all alternatives. This work demonstrates a framework for resolving the strategic basis of evasion in predator-prey interactions, which could be applied to a broad diversity of animals.


Assuntos
Comportamento Predatório , Peixe-Zebra , Animais , Peixe-Zebra/fisiologia , Larva/fisiologia , Comportamento Predatório/fisiologia , Reação de Fuga , Fenômenos Biomecânicos
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