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Patil VP, Tuazon H, Kaufman E, Chakrabortty T, Qin D, Dunkel J, Bhamla MS. Ultrafast reversible self-assembly of living tangled matter. Science 2023; 380:392-398. [PMID: 37104611 DOI: 10.1126/science.ade7759] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Tangled active filaments are ubiquitous in nature, from chromosomal DNA and cilia carpets to root networks and worm collectives. How activity and elasticity facilitate collective topological transformations in living tangled matter is not well understood. We studied California blackworms (Lumbriculus variegatus), which slowly form tangles in minutes but can untangle in milliseconds. Combining ultrasound imaging, theoretical analysis, and simulations, we developed and validated a mechanistic model that explains how the kinematics of individual active filaments determines their emergent collective topological dynamics. The model reveals that resonantly alternating helical waves enable both tangle formation and ultrafast untangling. By identifying generic dynamical principles of topological self-transformations, our results can provide guidance for designing classes of topologically tunable active materials.
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Affiliation(s)
- Vishal P Patil
- Department of Bioengineering, Stanford University, 475 Via Ortega, Stanford, CA 94305, USA
| | - Harry Tuazon
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30318, USA
| | - Emily Kaufman
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30318, USA
| | - Tuhin Chakrabortty
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30318, USA
| | - David Qin
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Jörn Dunkel
- Department of Mathematics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - M Saad Bhamla
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30318, USA
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2
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Ebbesen CL, Froemke RC. Automatic mapping of multiplexed social receptive fields by deep learning and GPU-accelerated 3D videography. Nat Commun 2022; 13:593. [PMID: 35105858 PMCID: PMC8807631 DOI: 10.1038/s41467-022-28153-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 01/06/2022] [Indexed: 12/25/2022] Open
Abstract
Social interactions powerfully impact the brain and the body, but high-resolution descriptions of these important physical interactions and their neural correlates are lacking. Currently, most studies rely on labor-intensive methods such as manual annotation. Scalable and objective tracking methods are required to understand the neural circuits underlying social behavior. Here we describe a hardware/software system and analysis pipeline that combines 3D videography, deep learning, physical modeling, and GPU-accelerated robust optimization, with automatic analysis of neuronal receptive fields recorded in interacting mice. Our system ("3DDD Social Mouse Tracker") is capable of fully automatic multi-animal tracking with minimal errors (including in complete darkness) during complex, spontaneous social encounters, together with simultaneous electrophysiological recordings. We capture posture dynamics of multiple unmarked mice with high spatiotemporal precision (~2 mm, 60 frames/s). A statistical model that relates 3D behavior and neural activity reveals multiplexed 'social receptive fields' of neurons in barrel cortex. Our approach could be broadly useful for neurobehavioral studies of multiple animals interacting in complex low-light environments.
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Affiliation(s)
- Christian L Ebbesen
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, USA.
- Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA.
- Department of Otolaryngology, New York University School of Medicine, New York, NY, 10016, USA.
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, USA.
- Center for Neural Science, New York University, New York, NY, 10003, USA.
| | - Robert C Froemke
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, USA.
- Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA.
- Department of Otolaryngology, New York University School of Medicine, New York, NY, 10016, USA.
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, USA.
- Center for Neural Science, New York University, New York, NY, 10003, USA.
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Abstract
We report a possible solution for the long-standing problem of the biological function of swirling motion, when a group of animals orbits a common center of the group. We exploit the hypothesis that learning processes in the nervous system of animals may be modelled by reinforcement learning (RL) and apply it to explain the phenomenon. In contrast to hardly justified models of physical interactions between animals, we propose a small set of rules to be learned by the agents, which results in swirling. The rules are extremely simple and thus applicable to animals with very limited level of information processing. We demonstrate that swirling may be understood in terms of the escort behavior, when an individual animal tries to reside within a certain distance from the swarm center. Moreover, we reveal the biological function of swirling motion: a trained for swirling swarm is by orders of magnitude more resistant to external perturbations, than an untrained one. Using our approach we analyze another class of a coordinated motion of animals-a group locomotion in viscous fluid. On a model example we demonstrate that RL provides an optimal disposition of coherently moving animals with a minimal dissipation of energy.
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Brilliantov NV, Abutuqayqah H, Tyukin IY, Matveev SA. Swirlonic state of active matter. Sci Rep 2020; 10:16783. [PMID: 33033334 PMCID: PMC7546729 DOI: 10.1038/s41598-020-73824-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/15/2020] [Indexed: 11/13/2022] Open
Abstract
We report a novel state of active matter—a swirlonic state. It is comprised of swirlons, formed by groups of active particles orbiting their common center of mass. These quasi-particles demonstrate a surprising behavior: In response to an external load they move with a constant velocity proportional to the applied force, just as objects in viscous media. The swirlons attract each other and coalesce forming a larger, joint swirlon. The coalescence is extremely slow, decelerating process, resulting in a rarified state of immobile quasi-particles. In addition to the swirlonic state, we observe gaseous, liquid and solid states, depending on the inter-particle and self-driving forces. Interestingly, in contrast to molecular systems, liquid and gaseous states of active matter do not coexist. We explain this unusual phenomenon by the lack of fast particles in active matter. We perform extensive numerical simulations and theoretical analysis. The predictions of the theory agree qualitatively and quantitatively with the simulation results.
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Affiliation(s)
- Nikolai V Brilliantov
- Skolkovo Institute of Science and Technology, Moscow, Russia.,Department of Mathematics, University of Leicester, Leicester, LE1 7RH, UK
| | - Hajar Abutuqayqah
- Department of Mathematics, University of Leicester, Leicester, LE1 7RH, UK
| | - Ivan Yu Tyukin
- Department of Mathematics, University of Leicester, Leicester, LE1 7RH, UK.,Saint Petersburg Electrotechnical University "LETI", Professora Popova 5, St. Petersburg, Russia
| | - Sergey A Matveev
- Skolkovo Institute of Science and Technology, Moscow, Russia. .,Marchuk Institute of Numerical Mathematics, RAS, Gubkin st. 8, Moscow, Russia.
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5
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Martinez P, Sprecher SG. Of Circuits and Brains: The Origin and Diversification of Neural Architectures. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00082] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Worley A, Sendova-Franks AB, Franks NR. Social flocculation in plant-animal worms. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181626. [PMID: 31032020 PMCID: PMC6458428 DOI: 10.1098/rsos.181626] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/25/2019] [Indexed: 05/13/2023]
Abstract
Individual animals can often move more safely or more efficiently as members of a group. This can be as simple as safety in numbers or as sophisticated as aerodynamic or hydrodynamic cooperation. Here, we show that individual plant-animal worms (Symsagittifera roscoffensis) can move to safety more quickly through flocculation. Flocs form in response to turbulence that might otherwise carry these beach-dwelling worms out to sea. They allow the worms to descend much more quickly to the safety of the substrate than single worms could swim. Descent speed increases with floc size such that larger flocs can catch up with smaller ones and engulf them to become even larger and faster. To our knowledge, this is the first demonstration of social flocculation in a wild, multicellular organism. It is also remarkable that such effective flocculation occurs where the components are comparatively large multicellular organisms organized as entangled ensembles.
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Affiliation(s)
- Alan Worley
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Ana B. Sendova-Franks
- Department of Engineering Design and Mathematics, UWE Bristol, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY, UK
| | - Nigel R. Franks
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
- Author for correspondence: Nigel R. Franks e-mail:
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Arboleda E, Hartenstein V, Martinez P, Reichert H, Sen S, Sprecher S, Bailly X. An Emerging System to Study Photosymbiosis, Brain Regeneration, Chronobiology, and Behavior: The Marine Acoel Symsagittifera roscoffensis. Bioessays 2018; 40:e1800107. [PMID: 30151860 DOI: 10.1002/bies.201800107] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/23/2018] [Indexed: 01/23/2023]
Abstract
The acoel worm Symsagittifera roscoffensis, an early offshoot of the Bilateria and the only well-studied marine acoel that lives in a photosymbiotic relationship, exhibits a centralized nervous system, brain regeneration, and a wide repertoire of complex behaviors such as circatidal rhythmicity, photo/geotaxis, and social interactions. While this animal can be collected by the thousands and is studied historically, significant progress is made over the last decade to develop it as an emerging marine model. The authors here present the feasibility of culturing it in the laboratory and describe the progress made on different areas, including genomic and tissue architectures, highlighting the associated challenges. In light of these developments, and on the ability to access abundant synchronized embryos, the authors put forward S. roscoffensis as a marine system to revisit questions in the areas of photosymbiosis, regeneration, chronobiology, and the study of complex behaviors from a molecular and evolutionary perspective.
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Affiliation(s)
- Enrique Arboleda
- Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | | | - Pedro Martinez
- Institut Català de Recerca i EstudisAvancats (ICREA), Passeig de Lluís Companys, 23, 08010 Barcelona, Spain
| | - Heinrich Reichert
- Departement de Biologie Universite de Fribourg, 1700 Fribourg, Switzerland
| | - Sonia Sen
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, Eugene, OR 97403
| | | | - Xavier Bailly
- CNRS, Station Biologique de Roscoff, 29680 Roscoff, France
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Sendova-Franks AB, Franks NR, Worley A. Plant-animal worms round themselves up in circular mills on the beach. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180665. [PMID: 30109112 PMCID: PMC6083728 DOI: 10.1098/rsos.180665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/27/2018] [Indexed: 05/27/2023]
Abstract
Collective motion is a fascinating and intensely studied manifestation of collective behaviour. Circular milling is an impressive example. It occurs in fishes, processionary caterpillars and army ants, among others. Its adaptive significance, however, is not yet well understood. Recently, we demonstrated experimentally circular milling in the marine plant-animal worm Symsagittifera roscoffensis. We hypothesized that its function is to gather the worms and facilitate the dense films they form on the beach to promote the photosynthesis of their symbiotic algae. Here, we report for the first time, to our knowledge, the occurrence of S. roscoffensis circular mills in nature and show that it is by no means rare. The size and behaviour of circular mills in their natural environment is compatible with our earlier experimental results. This makes S. roscoffensis a good study system for understanding the proximate and ultimate mechanisms of circular milling.
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Affiliation(s)
- Ana B. Sendova-Franks
- Department of Engineering Design and Mathematics, UWE Bristol, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY, UK
| | - Nigel R. Franks
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Alan Worley
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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9
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Abstract
Moving animal groups display remarkable feats of coordination. This coordination is largely achieved when individuals adjust their movement in response to their neighbours' movements and positions. Recent advancements in automated tracking technologies, including computer vision and GPS, now allow researchers to gather large amounts of data on the movements and positions of individuals in groups. Furthermore, analytical techniques from fields such as statistical physics now allow us to identify the precise interaction rules used by animals on the move. These interaction rules differ not only between species, but also between individuals in the same group. These differences have wide-ranging implications, affecting how groups make collective decisions and driving the evolution of collective motion. Here, I describe how trajectory data can be used to infer how animals interact in moving groups. I give examples of the similarities and differences in the spatial and directional organisations of animal groups between species, and discuss the rules that animals use to achieve this organisation. I then explore how groups of the same species can exhibit different structures, and ask whether this results from individuals adapting their interaction rules. I then examine how the interaction rules between individuals in the same groups can also differ, and discuss how this can affect ecological and evolutionary processes. Finally, I suggest areas of future research.
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Affiliation(s)
- J E Herbert-Read
- Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden Department of Mathematics, Uppsala University, S-75106 Uppsala, Sweden
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10
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Hejnol A, Pang K. Xenacoelomorpha's significance for understanding bilaterian evolution. Curr Opin Genet Dev 2016; 39:48-54. [PMID: 27322587 DOI: 10.1016/j.gde.2016.05.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 04/02/2016] [Accepted: 05/30/2016] [Indexed: 12/25/2022]
Abstract
The Xenacoelomorpha, with its phylogenetic position as sister group of the Nephrozoa (Protostomia+Deuterostomia), plays a key-role in understanding the evolution of bilaterian cell types and organ systems. Current studies of the morphological and developmental diversity of this group allow us to trace the evolution of different organ systems within the group and to reconstruct characters of the most recent common ancestor of Xenacoelomorpha. The disparity of the clade shows that there cannot be a single xenacoelomorph 'model' species and strategic sampling is essential for understanding the evolution of major traits. With this strategy, fundamental insights into the evolution of molecular mechanisms and their role in shaping animal organ systems can be expected in the near future.
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Affiliation(s)
- Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway.
| | - Kevin Pang
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
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