The Experts below are selected from a list of 726 Experts worldwide ranked by ideXlab platform
Sheryl Coombs - One of the best experts on this subject based on the ideXlab platform.
-
Rheotaxis revisited a multi behavioral and multisensory perspective on how fish orient to flow
The Journal of Experimental Biology, 2020Co-Authors: Sheryl Coombs, Joseph B Bakcoleman, John C MontgomeryAbstract:Here, we review fish Rheotaxis (orientation to flow) with the goal of placing it within a larger behavioral and multisensory context. Rheotaxis is a flexible behavior that is used by fish in a variety of circumstances: to search for upstream sources of current-borne odors, to intercept invertebrate drift and, in general, to conserve energy while preventing downstream displacement. Sensory information available for Rheotaxis includes water-motion cues to the lateral line and body-motion cues to visual, vestibular or tactile senses when fish are swept downstream. Although Rheotaxis can be mediated by a single sense, each sense has its own limitations. For example, lateral line cues are limited by the spatial characteristics of flow, visual cues by water visibility, and vestibular and other body-motion cues by the ability of fish to withstand downstream displacement. The ability of multiple senses to compensate for any single-sense limitation enables Rheotaxis to persist over a wide range of sensory and flow conditions. Here, we propose a mechanism of Rheotaxis that can be activated in parallel by one or more senses; a major component of this mechanism is directional selectivity of central neurons to broad patterns of water and/or body motions. A review of central mechanisms for vertebrate orienting behaviors and optomotor reflexes reveals several motorsensory integration sites in the CNS that could be involved in Rheotaxis. As such, Rheotaxis provides an excellent opportunity for understanding the multisensory control of a simple vertebrate behavior and how a simple motor act is integrated with others to form complex behaviors.
-
Rheotaxis performance increases with group size in a coupled phase model with sensory noise the effects of noise and group size on Rheotaxis
European Physical Journal-special Topics, 2015Co-Authors: Amanda Chicoli, Sheryl Coombs, Joseph B Bakcoleman, Derek A PaleyAbstract:Many fish exhibit Rheotaxis, a behavior in which fish orient themselves relative to flow. Rheotaxis confers many benefits, including energetic cost savings and interception of drifting prey. Despite the fact that most species of fish school during at least some portion of their life, little is known about the importance of rheotactic behavior to schooling fish and, conversely, how the presence of nearby conspecifics affects rheotactic behavior. Understanding how Rheotaxis is modified by social factors is thus of ecological importance. Here we present a mathematical model in the form of an all-to-all, coupled-oscillator framework over the non-Euclidean space of fish orientations to model group rheotactic behavior. Individuals in the model measure the orientation of their neighbors and the flow direction relative to their own orientation. These measures are corrupted by sensory noise. We study the effect of sensory noise and group size on internal (i.e., within the school) and external (i.e., with the flow) disagreement in orientation. We find that under noisy environmental conditions, increased group size improves Rheotaxis. Results of this study have implications for understanding animal behavior, as well as for potential applications in bio-inspired engineering.
-
going with then against the flow evidence against the optomotor hypothesis of fish Rheotaxis
Animal Behaviour, 2015Co-Authors: Joseph B Bakcoleman, Derek Smith, Sheryl CoombsAbstract:Movement through an environment provides sighted organisms with dynamic visual cues known as optic flow. In flying insects, optic flow is important for collision avoidance, flight speed control and landing manoeuvres. The function of optic flow is much less understood in other taxa, particularly in fish. Despite a lack of quantitative studies, optomotor responses (OMRs) to optic flow are presumed to be nearly ubiquitously important for Rheotaxis (orientation to currents), a widespread behaviour that confers a number of benefits, including energy conservation. Here we show that while very young larval zebrafish, Danio rerio, exhibit positive OMRs (swim in the direction of optic flow), thereby minimizing optic flow on the retina, older larvae and adults exhibit negative OMRs that increase optic flow. While the reason for this reversal remains unclear, negative OMRs are inconsistent with optically driven positive Rheotaxis (orienting upstream). Furthermore, when optic flow cues are placed in conflict with nonvisual (mechanical) cues generated by water currents, adult fish largely ignore the optic flow cues relying instead on nonvisual cues. These results challenge a century-old belief that optic flow and the resulting OMRs are a dominant sensorimotor mechanism in Rheotaxis, highlighting the importance of future work on life history changes in OMRs and the possible modulatory influence of learned, multisensory expectations.
-
The influence of turbulence on the sensory basis of Rheotaxis
Journal of Comparative Physiology A, 2015Co-Authors: John Elder, Sheryl CoombsAbstract:Rheotaxis is a widespread behavior with many potential benefits for fish and other aquatic animals, yet the sensory basis of Rheotaxis under different fluvial conditions is still poorly understood. Here, we examine the role that vision and the lateral line play in the rheotactic behavior of a stream-dwelling species (Mexican tetra, Astyanax mexicanus ) under both rectilinear and turbulent flow conditions. Turbulence lowered the flow speed at which threshold levels of rheotactic performance were elicited, an effect that was independent of sensory condition. Compared to fish with access to visual information, fish without access exhibited cross-stream casting behaviors and a decrease in the accuracy with which they oriented upstream. Visual deprivation effects were independent of availability of lateral line information and whether flow was rectilinear or turbulent. Fish deprived of lateral line information exhibited no measureable deficits under any of the conditions of this study. This study indicates that rheotactic abilities persist in the absence of both vision and lateral line under both turbulent and non-turbulent conditions, but that turbulence enhances either the motivation or ability of fish to orient to slow currents.
-
the lateral line is necessary for blind cavefish Rheotaxis in non uniform flow
The Journal of Experimental Biology, 2015Co-Authors: Matthew Kulpa, Joseph B Bakcoleman, Sheryl CoombsAbstract:When encountering a unidirectional flow, many fish exhibit an unconditioned orienting response known as Rheotaxis. This multisensory behavior can reportedly involve visual, vestibular, tactile and lateral line cues. However, the precise circumstances under which different senses contribute are still unclear and there is considerable debate, in particular, about the contributions of the lateral line. In this study, we investigate the rheotactic behavior of blind cavefish under conditions of spatially non-uniform flow (a jet stream), which in theory, should promote relianceonlateral linecues.The behaviorof individual lateral line enabled and disabled fish was videorecorded under IR light inasquarearenathatpreventedstreamwisebiasesandthatcontained anarrowjetstreaminthecenterofthetank.Whereasthestream’speak velocity (8 cm s −1 ) declined very little in the streamwise direction, it declined steeply in the cross-stream direction (∼3–4.5 cm s −1 cm −1 ). Lateral line enabled fish showed higher levels of orientation to the stream and its source (a 1-cm-wide nozzle) when in the central (jet stream)regionofthetankcomparedwithsurroundingregions,whereas laterallinedisabledfishshowedrandomorientationsinallregionsofthe tank. The results of this study indicate that the spatial characteristics of flow play a role in determining the sensory basis of Rheotaxis.
Waseem Asghar - One of the best experts on this subject based on the ideXlab platform.
-
Rheotaxis based microfluidic device for selecting sperm from samples infected with a virus
F&S Science, 2021Co-Authors: Afrouz Ataei, Alamgir Kabir, A W C Lau, Waseem AsgharAbstract:ABSTRACT Objective To investigate whether the presented Rheotaxis-based microfluidic device could be used to separate spermatozoa from viruses (i.e., zika) in the infected semen sample during the selection and washing process. Design Quantitative and experimental study of the sperm washing/selection process through the microfluidic platform exploiting the positive Rheotaxis of sperm. Setting None. Patient(s) None. Intervention(s) None. Main outcome measure(s) Human sperm were purchased from a sperm bank. The raw semen sample was mixed with viruses and loaded into a microfluidic device. Experiments were carried out with two different flow rates (0 and 25 μl/min) to investigate the washing efficiency of the device in the sperm selection process. The sperm sample was collected after 45 minutes and analyzed to check whether the collected sample is free of any infections (viruses) after isolation. Result(s) Fluorescent microscopy and quantitative Polymerase Chain Reaction (qPCR) based analysis showed that the sperm selected with presented Rheotaxis-based microfluidic device at the optimal flow rate (25 μl/min) was free of any viruses. Conclusion(s) We have developed a simple, cost-effective microfluidic device that mimics the conditions of the female genital tract while washing out the raw semen efficiently during the selection process for assisted reproductive technology (ART).
-
a microfluidic sperm sorting device based on Rheotaxis effect
Microfluidics and Nanofluidics, 2021Co-Authors: Afrouz Ataei, A W C Lau, Waseem AsgharAbstract:The ultimate challenge for assisted reproductive technologies (ARTs) is to select the most competent sperm population from a semen sample in an efficient way. In this paper, we report on an effective sperm sorting microfluidic device that exploits the Rheotaxis of sperm and investigates the sperm quality sorted under various flow conditions. Rheotaxis is the ability of a sperm cell to orient itself in the direction of the flow and swim against it. A novel passively driven pumping system is reported that provides a steady flow rate while it requires no external power source. We demonstrate that sperm selected with this device at a specific flow rate have higher motility, normal morphology, and a fewer degree of DNA fragmentation compared to a control group
-
Quantitative analysis of sperm Rheotaxis using a microfluidic device
Microfluidics and Nanofluidics, 2018Co-Authors: Kari Rappa, Jacob Samargia, Mazhar Sher, Javier S. Pino, Harold F. Rodriguez, Waseem AsgharAbstract:Quite puzzling issue in biology is how sperm cells are selected naturally where human sperm has to maintain a correct swimming behavior during the various stages of reproduction process. In nature, sperm has to compete a long journey from cervix to oocyte to stand a chance for fertilization. Although various guidance mechanisms such as chemical and thermal gradients are proposed previously, these mechanisms may only be relevant as sperm reaches very close to the oocyte. Rheotaxis, a phenomenon where sperm cells swim against the flow direction, is possibly the long-range sperm guidance mechanism for successful fertilization. A little is known quantitatively about how flow shear effects may help guide human sperm cells over long distances. Here, we have developed microfluidic devices to quantitatively investigate sperm Rheotaxis at various physiological flow conditions. We observed that at certain flow rates sperm actively orient and swim against the flow. Sperm that exhibit positive Rheotaxis show better motility and velocity than the control (no-flow condition), however, Rheotaxis does not select sperm based on hyaluronic acid (HA) binding potential and morphology. Morphology and HA binding potential may not be a significant factor in sperm transport in natural sperm selection.
Raymond E Goldstein - One of the best experts on this subject based on the ideXlab platform.
-
of mammalian sperm cells
2016Co-Authors: Vasily Kantsler, Jörn Dunkel, Martyn Blayney, Raymond E GoldsteinAbstract:Rheotaxis facilitates upstream navigatio
-
Rheotaxis facilitates upstream navigation of mammalian sperm cells
eLife, 2014Co-Authors: Vasily Kantsler, Jörn Dunkel, Martyn Blayney, Raymond E GoldsteinAbstract:A major puzzle in biology is how mammalian sperm maintain the correct swimming direction during various phases of the sexual reproduction process. Whilst chemotaxis may dominate near the ovum, it is unclear which cues guide spermatozoa on their long journey towards the egg. Hypothesized mechanisms range from peristaltic pumping to temperature sensing and response to fluid flow variations (Rheotaxis), but little is known quantitatively about them. We report the first quantitative study of mammalian sperm Rheotaxis, using microfluidic devices to investigate systematically swimming of human and bull sperm over a range of physiologically relevant shear rates and viscosities. Our measurements show that the interplay of fluid shear, steric surface-interactions, and chirality of the flagellar beat leads to stable upstream spiralling motion of sperm cells, thus providing a generic and robust rectification mechanism to support mammalian fertilisation. A minimal mathematical model is presented that accounts quantitatively for the experimental observations. DOI: http://dx.doi.org/10.7554/eLife.02403.001
-
Rheotaxis facilitates upstream navigation of mammalian sperm cells
eLife, 2014Co-Authors: Vasily Kantsler, Jörn Dunkel, Martyn Blayney, Raymond E GoldsteinAbstract:A sperm cell must complete a long and taxing journey to stand a chance of fertilising an egg cell. This quest covers a distance that is thousands of times longer than the length of a sperm cell. It also passes through the diverse environments of the cervix, the uterus and, finally, the oviduct, where there might be an egg to fertilise. How the sperm cells manage to stay on course over this distance is a mystery, although it has been suggested that many different factors, including chemical signals and fluid flow, are involved. The fluids that the sperm cells travel through are not static. Evidence suggests that contractions of the cervix and uterus help to pump sperm cells along the first part of their journey. However, mucus flows out of the oviduct in the opposite direction to way the sperm cells need to go. Sperm cells mostly move along the walls of the cervix, uterus, and oviduct. This means that sperm cells must contend with two properties of the fluids they travel through—the viscosity (or ‘thickness’) of the fluid, and the fact that different parts of the fluid will flow at different speeds, depending on how close it is to the wall (‘shear flow’). Kantsler et al. have now used a technique called microfluidics—which involves forcing tiny amounts of liquid to flow through very narrow channels—to study how the movement of human and bull sperm cells along a surface is affected by the viscosity and flow rate of the fluid they are swimming through. The sperm cells were found to swim upstream, moving along the walls of the channels in a spiral movement. This is likely to help the sperm cells to find the egg, because spiralling around the oviduct will increase the chances of meeting the egg. Kantsler et al. also built a mathematical model that describes how the sperm cells move. Although further work is needed to better understand the role played by chemical signals, understanding how fluid flow and viscosity influence sperm cells could lead to more effective artificial insemination techniques.
Raphael Candelier - One of the best experts on this subject based on the ideXlab platform.
-
Rheotaxis of larval zebrafish behavioral study of a multi sensory process
Frontiers in Systems Neuroscience, 2016Co-Authors: Raphael Olive, Sebastien Wolf, Alexis M Dubreuil, Volker Bormuth, Georges Debregeas, Raphael CandelierAbstract:Rheotaxis is the ability shared by most aquatic species to orient towards a current and swim to hold position. It is an innate and robust multi-sensory behavior that is known to involve the lateral line and visual systems. To facilitate the neuroethological study of rheotaxic behavior in larval zebrafish we developed an assay for freely swimming larvae that allows for high experimental throughput, large statistics and a detailed description of the behavior. We show that there exist a clear transition from exploration to counterflow swim, and by changing the sensory modalities accessible to the fishes (visual only, lateral line only or both) and comparing the swim patterns at different ages we characterized two different mechanisms for position holding, one mediated by the lateral line and one mediated by the visual system. We found that when both sensory modalities are accessible the lateral line dominates for triggering the transition while the visual system overshadows the lateral line for all aspect of swim patterns during the position holding phase. This suggests that at the larval stage the sensory inputs are not merged to finely tune the behavior but that one sensory modality dominates the behavioral response while redundant information pathways may be used as functional fallbacks.
-
Rheotaxis of larval zebrafish behavioral study of a multi sensory process
Frontiers in Systems Neuroscience, 2016Co-Authors: Raphael Olive, Sebastien Wolf, Volker Bormuth, Georges Debregeas, Alexis Dubreuil, Raphael CandelierAbstract:Awake animals unceasingly perceive sensory inputs with great variability of nature and intensity, and understanding how the nervous system manages this continuous flow of diverse information to get a coherent representation of the environment is arguably a central question in systems neuroscience. Rheotaxis, the ability shared by most aquatic species to orient toward a current and swim to hold position, is an innate and robust multi-sensory behavior that is known to involve the lateral line and visual systems. To facilitate the neuroethological study of rheotaxic behavior in larval zebrafish we developed an assay for freely swimming larvae that allows for high experimental throughtput, large statistic and a fine description of the behavior. We show that there exist a clear transition from exploration to counterflow swim, and by changing the sensory modalities accessible to the fishes (visual only, lateral line only or both) and comparing the swim patterns at different ages we were able to detect and characterize two different mechanisms for position holding, one mediated by the lateral line and one mediated by the visual system. We also found that when both sensory modalities are accessible the visual system overshadows the lateral line, suggesting that at the larval stage the sensory inputs are not merged to finely tune the behavior but that redundant information pathways may be used as functional fallbacks.
Andreas Zottl - One of the best experts on this subject based on the ideXlab platform.
-
chirality induced bacterial Rheotaxis in bulk shear flows
arXiv: Soft Condensed Matter, 2020Co-Authors: E Clement, Andreas Zottl, Guangyin Jing, Anke LindnerAbstract:Interaction of swimming bacteria with flows controls their ability to explore complex environments, crucial to many societal and environmental challenges and relevant for microfluidic applications as cell sorting. Combining experimental, numerical and theoretical analysis, we present a comprehensive study of the transport of motile bacteria in shear flows. Experimentally, we obtain with high accuracy and for a large range of flow rates, the spatially resolved velocity and orientation distributions. They are in excellent agreement with the simulations of a kinematic model accounting for stochastic and microhydrodynamic properties and in particular the flagella chirality. Theoretical analysis reveals the scaling laws behind the average rheotactic velocity at moderate shear rates using a chirality parameter and explains the reorientation dynamics leading to a saturation at large shear rates from the marginal stability of a fixed point. Our findings constitute a full understanding of the physical mechanisms and relevant parameters of bacteria bulk Rheotaxis.
-
oscillatory surface Rheotaxis of swimming e coli bacteria
Nature Communications, 2019Co-Authors: Arnold J T M Mathijssen, Nuris Figueroamorales, Gaspard Junot, E Clement, Anke Lindner, Andreas ZottlAbstract:Bacterial contamination of biological channels, catheters or water resources is a major threat to public health, which can be amplified by the ability of bacteria to swim upstream. The mechanisms of this ‘Rheotaxis’, the reorientation with respect to flow gradients, are still poorly understood. Here, we follow individual E. coli bacteria swimming at surfaces under shear flow using 3D Lagrangian tracking and fluorescent flagellar labelling. Three transitions are identified with increasing shear rate: Above a first critical shear rate, bacteria shift to swimming upstream. After a second threshold, we report the discovery of an oscillatory Rheotaxis. Beyond a third transition, we further observe coexistence of Rheotaxis along the positive and negative vorticity directions. A theoretical analysis explains these Rheotaxis regimes and predicts the corresponding critical shear rates. Our results shed light on bacterial transport and reveal strategies for contamination prevention, rheotactic cell sorting, and microswimmer navigation in complex flow environments. Bacteria can swim upstream by reorienting with respect to fluid flows. Here, the authors observe an oscillatory motion and describe the mechanisms behind these reorientation dynamics, which could help designing strategies for bacterial contamination prevention.
-
oscillatory surface Rheotaxis of swimming e coli bacteria
arXiv: Soft Condensed Matter, 2018Co-Authors: Arnold J T M Mathijssen, Nuris Figueroamorales, Gaspard Junot, E Clement, Anke Lindner, Andreas ZottlAbstract:Bacterial contamination of biological conducts, catheters or water resources is a major threat to public health and can be amplified by the ability of bacteria to swim upstream. The mechanisms of this Rheotaxis, the reorientation with respect to flow gradients, often in complex and confined environments, are still poorly understood. Here, we follow individual E. coli bacteria swimming at surfaces under shear flow with two complementary experimental assays, based on 3D Lagrangian tracking and fluorescent flagellar labelling and we develop a theoretical model for their rheotactic motion. Three transitions are identified with increasing shear rate: Above a first critical shear rate, bacteria shift to swimming upstream. After a second threshold, we report the discovery of an oscillatory Rheotaxis. Beyond a third transition, we further observe coexistence of Rheotaxis along the positive and negative vorticity directions. A full theoretical analysis explains these regimes and predicts the corresponding critical shear rates. The predicted transitions as well as the oscillation dynamics are in good agreement with experimental observations. Our results shed new light on bacterial transport and reveal new strategies for contamination prevention.