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Bray SR, Wyss LS, Chai C, Lozada ME, Wang B. Adaptive robustness through incoherent signaling mechanisms in a regenerative brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.523817. [PMID: 36711454 PMCID: PMC9882340 DOI: 10.1101/2023.01.20.523817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Animal behavior emerges from collective dynamics of interconnected neurons, making it vulnerable to connectome damage. Paradoxically, many organisms maintain significant behavioral output after large-scale neural injury. Molecular underpinnings of this extreme robustness remain largely unknown. Here, we develop a quantitative behavioral analysis pipeline to measure previously uncharacterized long-lasting latent memory states in planarian flatworms during whole-brain regeneration. By combining >20,000 animal trials with neural population dynamic modeling, we show that long-range volumetric peptidergic signals allow the planarian to rapidly reestablish latent states and restore coarse behavior after large structural perturbations to the nervous system, while small-molecule neuromodulators gradually refine the precision. The different time and length scales of neuropeptide and small-molecule transmission generate incoherent patterns of neural activity which competitively regulate behavior and memory. Controlling behavior through opposing communication mechanisms creates a more robust system than either alone and may serve as a generic approach to construct robust neural networks.
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Affiliation(s)
- Samuel R. Bray
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Livia S. Wyss
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Maria E. Lozada
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA
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2
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Tran TA, Gentile L. A lineage CLOUD for neoblasts. Semin Cell Dev Biol 2018; 87:22-29. [PMID: 29727726 DOI: 10.1016/j.semcdb.2018.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/10/2018] [Accepted: 04/25/2018] [Indexed: 12/18/2022]
Abstract
In planarians, pluripotency can be studied in vivo in the adult animal, making these animals a unique model system where pluripotency-based regeneration (PBR)-and its therapeutic potential-can be investigated. This review focuses on recent findings to build a cloud model of fate restriction likelihood for planarian stem and progenitor cells. Recently, a computational approach based on functional and molecular profiling at the single cell level was proposed for human hematopoietic stem cells. Based on data generated both in vivo and ex vivo, we hypothesized that planarian stem cells could acquire multiple direction lineage biases, following a "badlands" landscape. Instead of a discrete tree-like hierarchy, where the potency of stem/progenitor cells reduces stepwise, we propose a Continuum of LOw-primed UnDifferentiated Planarian Stem/Progenitor Cells (CLOUD-PSPCs). Every subclass of neoblast/progenitor cells is a cloud of likelihood, as the single cell transcriptomics data indicate. The CLOUD-HSPCs concept was substantiated by in vitro data from cell culture; therefore, to confirm the CLOUD-PSPCs model, the planarian community needs to develop new tools, like live cell tracking. Future studies will allow a deeper understanding of PBR in planarian, and the possible implications for regenerative therapies in human.
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Affiliation(s)
- Thao Anh Tran
- Pluripotency and Regeneration Group, Fraunhofer Institute for Biomedical Engineering, Joseph-von-Fraunhofer-Weg, 1, 66280, Sulzbach, Germany
| | - Luca Gentile
- Pluripotency and Regeneration Group, Fraunhofer Institute for Biomedical Engineering, Joseph-von-Fraunhofer-Weg, 1, 66280, Sulzbach, Germany; Planarian Stem Cell Laboratory, Max Planck Institute for Molecular Biomedicine, von-Esmarch-str. 54, 48149, Münster, Germany; Hasselt University - Campus Diepenbeek, Agoralaan building D, 3590, Diepenbeek, Belgium.
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Morokuma J, Durant F, Williams KB, Finkelstein JM, Blackiston DJ, Clements T, Reed DW, Roberts M, Jain M, Kimel K, Trauger SA, Wolfe BE, Levin M. Planarian regeneration in space: Persistent anatomical, behavioral, and bacteriological changes induced by space travel. ACTA ACUST UNITED AC 2017; 4:85-102. [PMID: 28616247 PMCID: PMC5469732 DOI: 10.1002/reg2.79] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/27/2017] [Accepted: 04/21/2017] [Indexed: 12/14/2022]
Abstract
Regeneration is regulated not only by chemical signals but also by physical processes, such as bioelectric gradients. How these may change in the absence of the normal gravitational and geomagnetic fields is largely unknown. Planarian flatworms were moved to the International Space Station for 5 weeks, immediately after removing their heads and tails. A control group in spring water remained on Earth. No manipulation of the planaria occurred while they were in orbit, and space‐exposed worms were returned to our laboratory for analysis. One animal out of 15 regenerated into a double‐headed phenotype—normally an extremely rare event. Remarkably, amputating this double‐headed worm again, in plain water, resulted again in the double‐headed phenotype. Moreover, even when tested 20 months after return to Earth, the space‐exposed worms displayed significant quantitative differences in behavior and microbiome composition. These observations may have implications for human and animal space travelers, but could also elucidate how microgravity and hypomagnetic environments could be used to trigger desired morphological, neurological, physiological, and bacteriomic changes for various regenerative and bioengineering applications.
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Affiliation(s)
- Junji Morokuma
- Allen Discovery Center at Tufts University Biology Department Tufts University 200 Boston Ave., Suite 4600 Medford MA 02155-4243 USA
| | - Fallon Durant
- Allen Discovery Center at Tufts University Biology Department Tufts University 200 Boston Ave., Suite 4600 Medford MA 02155-4243 USA
| | - Katherine B Williams
- Allen Discovery Center at Tufts University Biology Department Tufts University 200 Boston Ave., Suite 4600 Medford MA 02155-4243 USA
| | - Joshua M Finkelstein
- Allen Discovery Center at Tufts University Biology Department Tufts University 200 Boston Ave., Suite 4600 Medford MA 02155-4243 USA
| | - Douglas J Blackiston
- Allen Discovery Center at Tufts University Biology Department Tufts University 200 Boston Ave., Suite 4600 Medford MA 02155-4243 USA
| | - Twyman Clements
- Kentucky Space LLC, 200 West Vine St., Suite 420 Lexington KY 40507 USA
| | - David W Reed
- NASA Kennedy Space Center Space Station Processing Facility Building M7-0360, Kennedy Space Center FL 32899 USA
| | - Michael Roberts
- Center for the Advancement of Science in Space (CASIS) 6905 N. Wickham Rd., Suite 500 Melbourne FL 32940 USA
| | - Mahendra Jain
- Kentucky Space LLC, 200 West Vine St., Suite 420 Lexington KY 40507 USA
| | - Kris Kimel
- Exomedicine Institute 200 West Vine St. Lexington KY 40507 USA
| | - Sunia A Trauger
- Harvard University Small Molecule Mass Spectrometry Facility 52 Oxford St. Cambridge MA 02138 USA
| | - Benjamin E Wolfe
- Allen Discovery Center at Tufts University Biology Department Tufts University 200 Boston Ave., Suite 4600 Medford MA 02155-4243 USA
| | - Michael Levin
- Allen Discovery Center at Tufts University Biology Department Tufts University 200 Boston Ave., Suite 4600 Medford MA 02155-4243 USA
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DONG Z, YUWEN Y, SIMA Y, DONG Y, ZHAN H, CHEN G, LIU D. Photokinesis andDjopsingene expression analysis during the regeneration of planarian eyes. Integr Zool 2017; 12:157-164. [DOI: 10.1111/1749-4877.12234] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Zimei DONG
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Yanqing YUWEN
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Yingxu SIMA
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Yanping DONG
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Huina ZHAN
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Guangwen CHEN
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Dezeng LIU
- College of Life Science; Henan Normal University; Xinxiang Henan China
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Inoue T, Hoshino H, Yamashita T, Shimoyama S, Agata K. Planarian shows decision-making behavior in response to multiple stimuli by integrative brain function. ZOOLOGICAL LETTERS 2015; 1:7. [PMID: 26605052 PMCID: PMC4657317 DOI: 10.1186/s40851-014-0010-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/27/2014] [Indexed: 05/03/2023]
Abstract
INTRODUCTION Planarians belong to an evolutionarily early group of organisms that possess a central nervous system including a well-organized brain with a simple architecture but many types of neurons. Planarians display a number of behaviors, such as phototaxis and thermotaxis, in response to external stimuli, and it has been shown that various molecules and neural pathways in the brain are involved in controlling these behaviors. However, due to the lack of combinatorial assay methods, it remains obscure whether planarians possess higher brain functions, including integration in the brain, in which multiple signals coming from outside are coordinated and used in determining behavioral strategies. RESULTS In the present study, we designed chemotaxis and thigmotaxis/kinesis tracking assays to measure several planarian behaviors in addition to those measured by phototaxis and thermotaxis assays previously established by our group, and used these tests to analyze planarian chemotactic and thigmotactic/kinetic behaviors. We found that headless planarian body fragments and planarians that had specifically lost neural activity following regeneration-dependent conditional gene knockdown (Readyknock) of synaptotagmin in the brain lost both chemotactic and thigmotactic behaviors, suggesting that neural activity in the brain is required for the planarian's chemotactic and thigmotactic behaviors. Furthermore, we compared the strength of phototaxis, chemotaxis, thigmotaxis/kinesis, and thermotaxis by presenting simultaneous binary stimuli to planarians. We found that planarians showed a clear order of predominance of these behaviors. For example, when planarians were simultaneously exposed to 400 lux of light and a chemoattractant, they showed chemoattractive behavior irrespective of the direction of the light source, although exposure to light of this intensity alone induces evasive behavior away from the light source. In contrast, when the light intensity was increased to 800 or 1600 lux and the same dose of chemoattractant was presented, planarian behaviors were gradually shifted to negative phototaxis rather than chemoattraction. These results suggest that planarians may be capable of selecting behavioral strategies via the integration of discrete brain functions when exposed to multiple stimuli. CONCLUSIONS The planarian brain processes external signals received through the respective sensory neurons, thereby resulting in the production of appropriate behaviors. In addition, planarians can adjust behavioral features in response to stimulus conditions by integrating multiple external signals in the brain.
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Affiliation(s)
- Takeshi Inoue
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Hajime Hoshino
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Taiga Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Seira Shimoyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
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On-chip immobilization of planarians for in vivo imaging. Sci Rep 2014; 4:6388. [PMID: 25227263 PMCID: PMC4165980 DOI: 10.1038/srep06388] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 08/14/2014] [Indexed: 11/08/2022] Open
Abstract
Planarians are an important model organism for regeneration and stem cell research. A complete understanding of stem cell and regeneration dynamics in these animals requires time-lapse imaging in vivo, which has been difficult to achieve due to a lack of tissue-specific markers and the strong negative phototaxis of planarians. We have developed the Planarian Immobilization Chip (PIC) for rapid, stable immobilization of planarians for in vivo imaging without injury or biochemical alteration. The chip is easy and inexpensive to fabricate, and worms can be mounted for and removed after imaging within minutes. We show that the PIC enables significantly higher-stability immobilization than can be achieved with standard techniques, allowing for imaging of planarians at sub-cellular resolution in vivo using brightfield and fluorescence microscopy. We validate the performance of the PIC by performing time-lapse imaging of planarian wound closure and sequential imaging over days of head regeneration. We further show that the device can be used to immobilize Hydra, another photophobic regenerative model organism. The simple fabrication, low cost, ease of use, and enhanced specimen stability of the PIC should enable its broad application to in vivo studies of stem cell and regeneration dynamics in planarians and Hydra.
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Davidson C, Prados J, Gibson CL, Young AMJ, Barnes D, Sherlock R, Hutchinson CV. Shedding light on photosensitive behaviour in brown planaria (Dugesia Tigrina). Perception 2011; 40:743-6. [PMID: 21936302 DOI: 10.1068/p6949] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The planarian flatworm is one of the simplest animals to develop two eyecups that enable them to detect the presence and direction of light, which they typically avoid. In this study we assessed responses of planaria to different intensities of light. We found that they exhibited a graded, sigmoidal, photonegative response to light intensity. A two-octave increase in luminance (on the upward slope of the sigmoid) corresponded to a 9% increase in the speed planaria travelled to avoid light.
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Affiliation(s)
- Colin Davidson
- Division of Biomedical Sciences, St Georges, University of London, Cranmer Terrace, London SW17 0RE, UK
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Dong Z, Yuwen Y, Wang Q, Chen G, Liu D. Expression analysis of Djsix-1 gene during regeneration of planarian eyespots. Mol Biol Rep 2010; 38:3977-82. [DOI: 10.1007/s11033-010-0515-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 11/13/2010] [Indexed: 10/18/2022]
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Lopes KAR, Campos Velho NMR, Munin E. A study of low power laser on the regenerative process of Girardia tigrina (Girard,1850) (Turbellaria; Tricladida; Dugesiidae). BRAZ J BIOL 2009; 69:327-32. [DOI: 10.1590/s1519-69842009000200013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Accepted: 07/27/2007] [Indexed: 11/22/2022] Open
Abstract
The mechanism of regeneration does not start to restore the wound until its corresponding epimorphic phase. A bioestimulation of tissues and cells by laser radiation depends on the wavelength, on the dose, and on the intensity of the light. The goal of this work was to verify the effect of the low power laser at 660 nm on the regenerative process of Girardia tigrina. The specimens were maintained in the laboratory under a temperature ranging from 19° up to 24 °C for 21 days. The planarians were anesthetized by placing them on ice and then cut them with a scalpel. The three treatments were as following: animals individually irradiated with 14 sessions with 1 minute duration (treatment 1), 14 sessions with 3 minutes duration (treatment 2), and without irradiation (control). The planarians were amputated and divided in three study treatments: a control group (without radiation), and two other treatments: irradiated for 1 minute, and irradiated for 3 minutes. The animals were irradiated with diode laser (660 nm) with 3.3 ± 0.3 mW of power, using 0.94 mW.mm-2 power density for each irradiation procedure. During the experiment, 14 irradiation sessions were undertaken. The specimens were fixed in Bouin, and stained with hematoxyline and eosin. From observation and histological analysis, it was possible to assess the effects of interaction between laser and tissue. The head fragment after 1 minute of irradiation presented a better organized tissue scheme, when compared with the other treatments. Aspects of the body fragments submitted to 3 minutes of light treatment were very similar to fragments that had not been injured. It can be concluded that there are changes in the quality of regeneration when treated with low power laser under the conditions mentioned above.
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Affiliation(s)
| | | | - E. Munin
- Universidade Camilo Castelo Branco, Brazil
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Inoue T, Kumamoto H, Okamoto K, Umesono Y, Sakai M, Sánchez Alvarado A, Agata K. Morphological and Functional Recovery of the Planarian Photosensing System during Head Regeneration. Zoolog Sci 2004; 21:275-83. [PMID: 15056922 DOI: 10.2108/zsj.21.275] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
When exposed to light, planarians display a distinctive light avoidance behavior known as negative phototaxis. Such behavior is temporarily suppressed when animals are decapitated, and it is restored once the animals regenerate their heads. Head regeneration and the simple but reproducible phototactic response of planarians provides an opportunity to study the association between neuronal differentiation and the establishment of behavior in a simple, experimentally tractable metazoan. We have devised a phototaxis assay system to analyze light response recovery during head regeneration and determined that light evasion is markedly re-established 5 days after amputation. Immunohistological and in situ hybridization studies indicate that the photoreceptors and optic nerve connections to the brain begin by the fourth day of cephalic regeneration. To experimentally manipulate the light response recovery, we performed gene knockdown analysis using RNA interference (RNAi) on two genes (1020HH and eye53) previously reported to be expressed at 5 days after amputation and in the dorso-medial region of the brain (where the optic nerves project). Although RNAi failed to produce morphological defects in either the brain or the visual neurons, the recovery of the phototactic response normally observed in 5-day regenerates was significantly suppressed. The data suggest that 1020HH and eye53 may be involved in the functional recovery and maintenance of the visual system, and that the phototaxis assay presented here can be used to reliably quantify the negative phototactic behavior of planarians.
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Affiliation(s)
- Takeshi Inoue
- Faculty of Biomolecular Science, Okayama University Graduate School of Natural Science and Technology, Japan
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