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Amplatz K, Zieger E, Abed-Navandi D, Weissenbacher A, Wanninger A. Neuromuscular development in the emerging scyphozoan model system, Cassiopea xamachana: implications for the evolution of cnidarian nervous systems. Front Neurosci 2024; 17:1324980. [PMID: 38274504 PMCID: PMC10808518 DOI: 10.3389/fnins.2023.1324980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024] Open
Abstract
The scyphozoan Cassiopea xamachana is an emerging cnidarian model system for studying regeneration, animal-algae symbiotic relationships, and various aspects of evolutionary biology including the early emergence of animal nervous systems. Cassiopea has a life cycle similar to other scyphozoans, which includes the alternation between a sessile, asexual form (polyp) and a sexually reproducing stage, the medusa. The transition between the two forms is called strobilation, where the polyp releases a miniature medusa, the iconic ephyra, that subsequently develops into the adult medusa. In addition, Cassiopea polyps may reproduce asexually by budding off free-swimming so-called planuloid buds. While the development of planuloid buds and polyps has been studied in some detail, little is known about the ontogeny of the sexually produced planula larva. Using immunofluorescence labeling and confocal microscopy, we examined neuromuscular development during metamorphosis of the planula larva into the juvenile polyp in C. xamachana. For this purpose, we used tyrosinated α-tubulin-, FMRFamide- and serotonin-like immunoreactivity together with phalloidin labeling. Our results show a planula nervous system that consists of a basiectodermal neural plexus with mostly longitudinally oriented neurites. This neural meshwork is connected to sensory neurons in the superficial stratum of the ectoderm, which are exclusively localized in the aboral half of the larva. During settlement, this aborally concentrated nervous system of the planula is replaced completely by the orally concentrated nervous system of the polyp. Adult polyps show an extensive nerve net with a loose concentration around the oral disc. These findings are consistent with data from other scyphozoans and most likely constitute a conserved feature of scyphozoan discomedusae. Taken together, the data currently available suggest an aborally concentrated nervous system including sensory cells as part of the neural ground pattern of cnidarian planula larvae. The reorganization of the nervous system from anterior to posterior in planula-to-polyp metamorphosis most likely also constitutes an ancestral trait in cnidarian evolution.
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Affiliation(s)
- Klara Amplatz
- Department of Evolutionary Biology, University of Vienna, Vienna, Austria
| | - Elisabeth Zieger
- Department of Evolutionary Biology, University of Vienna, Vienna, Austria
| | - Daniel Abed-Navandi
- Department of Evolutionary Biology, University of Vienna, Vienna, Austria
- Haus des Meeres, Vienna, Austria
| | | | - Andreas Wanninger
- Department of Evolutionary Biology, University of Vienna, Vienna, Austria
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2
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Durieux DM, Scrogham GD, Fender C, Lewis DB, Deban SM, Gemmell BJ. Benthic jellyfish act as suction pumps to facilitate release of interstitial porewater. Sci Rep 2023; 13:3770. [PMID: 36882452 PMCID: PMC9992524 DOI: 10.1038/s41598-023-30101-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 02/15/2023] [Indexed: 03/09/2023] Open
Abstract
Upside-down jellyfish, genus Cassiopea (Péron and Lesueur, 1809), are found in shallow coastal habitats in tropical and subtropical regions circumglobally. These animals have previously been demonstrated to produce flow both in the water column as a feeding current, and in the interstitial porewater, where they liberate porewater at rates averaging 2.46 mL h-1. Since porewater in Cassiopea habitat can be nutrient-rich, this is a potential source of nutrient enrichment in these ecosystems. This study experimentally determines that porewater release by Cassiopea sp. jellyfish is due to suction pumping, and not the Bernoulli effect. This suggests porewater release is directly coupled to bell pulsation rate, and unlike vertical jet flux, should be unaffected by population density. In addition, we show that bell pulsation rate is positively correlated with temperature, and negatively correlated with animal size. As such, we would predict an increase in the release of nutrient-rich porewater during the warm summer months. Furthermore, we show that, at our field site in Lido Key, Florida, at the northernmost limit of Cassiopea range, population densities decline during the winter, increasing seasonal differences in porewater release.
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Affiliation(s)
- David M Durieux
- University of South Florida, 4202 E Fowler Ave, Tampa, FL, 33620, USA
| | | | - Christian Fender
- University of South Florida, 4202 E Fowler Ave, Tampa, FL, 33620, USA
| | - David B Lewis
- University of South Florida, 4202 E Fowler Ave, Tampa, FL, 33620, USA
| | - Stephen M Deban
- University of South Florida, 4202 E Fowler Ave, Tampa, FL, 33620, USA
| | - Brad J Gemmell
- University of South Florida, 4202 E Fowler Ave, Tampa, FL, 33620, USA.
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Pallasdies F, Goedeke S, Braun W, Memmesheimer RM. From single neurons to behavior in the jellyfish Aurelia aurita. eLife 2019; 8:e50084. [PMID: 31868586 PMCID: PMC6999044 DOI: 10.7554/elife.50084] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 12/22/2019] [Indexed: 01/13/2023] Open
Abstract
Jellyfish nerve nets provide insight into the origins of nervous systems, as both their taxonomic position and their evolutionary age imply that jellyfish resemble some of the earliest neuron-bearing, actively-swimming animals. Here, we develop the first neuronal network model for the nerve nets of jellyfish. Specifically, we focus on the moon jelly Aurelia aurita and the control of its energy-efficient swimming motion. The proposed single neuron model disentangles the contributions of different currents to a spike. The network model identifies factors ensuring non-pathological activity and suggests an optimization for the transmission of signals. After modeling the jellyfish's muscle system and its bell in a hydrodynamic environment, we explore the swimming elicited by neural activity. We find that different delays between nerve net activations lead to well-controlled, differently directed movements. Our model bridges the scales from single neurons to behavior, allowing for a comprehensive understanding of jellyfish neural control of locomotion.
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Affiliation(s)
- Fabian Pallasdies
- Neural Network Dynamics and Computation, Institute of GeneticsUniversity of BonnBonnGermany
| | - Sven Goedeke
- Neural Network Dynamics and Computation, Institute of GeneticsUniversity of BonnBonnGermany
| | - Wilhelm Braun
- Neural Network Dynamics and Computation, Institute of GeneticsUniversity of BonnBonnGermany
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Norekian TP, Moroz LL. Atlas of the neuromuscular system in the Trachymedusa Aglantha digitale: Insights from the advanced hydrozoan. J Comp Neurol 2019; 528:1231-1254. [PMID: 31749185 DOI: 10.1002/cne.24821] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/17/2019] [Accepted: 11/18/2019] [Indexed: 01/26/2023]
Abstract
Cnidaria is the sister taxon to bilaterian animals, and therefore, represents a key reference lineage to understand early origins and evolution of the neural systems. The hydromedusa Aglantha digitale is arguably the best electrophysiologically studied jellyfish because of its system of giant axons and unique fast swimming/escape behaviors. Here, using a combination of scanning electron microscopy and immunohistochemistry together with phalloidin labeling, we systematically characterize both neural and muscular systems in Aglantha, summarizing and expanding further the previous knowledge on the microscopic neuroanatomy of this crucial reference species. We found that the majority, if not all (~2,500) neurons, that are labeled by FMRFamide antibody are different from those revealed by anti-α-tubulin immunostaining, making these two neuronal markers complementary to each other and, therefore, expanding the diversity of neural elements in Aglantha with two distinct neural subsystems. Our data uncovered the complex organization of neural networks forming a functional "annulus-type" central nervous system with three subsets of giant axons, dozen subtypes of neurons, muscles, and a variety of receptors fully integrated with epithelial conductive pathways supporting swimming, escape and feeding behaviors. The observed unique adaptations within the Aglantha lineage (including giant axons innervating striated muscles) strongly support an extensive and wide-spread parallel evolution of integrative and effector systems across Metazoa.
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Affiliation(s)
- Tigran P Norekian
- Whitney Laboratory for Marine Biosciences, University of Florida, St. Augustine, Florida.,Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington.,Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - Leonid L Moroz
- Whitney Laboratory for Marine Biosciences, University of Florida, St. Augustine, Florida.,Department of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, Florida
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Bouchard C, Boudko DY, Jiang RHY. A SLC6 transporter cloned from the lion's mane jellyfish (Cnidaria, Scyphozoa) is expressed in neurons. PLoS One 2019; 14:e0218806. [PMID: 31233570 PMCID: PMC6590891 DOI: 10.1371/journal.pone.0218806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/10/2019] [Indexed: 11/18/2022] Open
Abstract
In the course of recent comparative genomic studies conducted on nervous systems across the phylogeny, current thinking is leaning in favor of more heterogeneity among nervous systems than what was initially expected. The isolation and characterization of molecular components that constitute the cnidarian neuron is not only of interest to the physiologist but also, on a larger scale, to those who study the evolution of nervous systems. Understanding the function of those ancient neurons involves the identification of neurotransmitters and their precursors, the description of nutrients used by neurons for metabolic purposes and the identification of integral membrane proteins that bind to those compounds. Using a molecular cloning strategy targeting membrane proteins that are known to be present in all forms of life, we isolated a member of the solute carrier family 6 from the scyphozoan jellyfish Cyanea capillata. The phylogenetic analysis suggested that the new transporter sequence belongs to an ancestral group of the nutrient amino acid transporter subfamily and is part of a cluster of cnidarian sequences which may translocate the same substrate. We found that the jellyfish transporter is expressed in neurons of the motor nerve net of the animal. To this end, we established an in situ hybridization protocol for the tissues of C. capillata and developed a specific antibody to the jellyfish transporter. Finally, we showed that the gene that codes for the jellyfish transporter also expresses a long non-coding RNA. We hope that this research will contribute to studies that seek to understand what constitutes a neuron in species that belong to an ancient phylum.
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Affiliation(s)
- Christelle Bouchard
- College of Science and Mathematics, University of South Florida, Sarasota, Florida, United States of America
| | - Dmitri Y. Boudko
- Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science, Chicago Medical School, North Chicago, Illinois, United States of America
| | - Rays H. Y. Jiang
- Global and Planetary Health, College of Public Health, University of South Florida USF Genomics Program, Tampa, Florida, United States of America
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6
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Helm RR. Evolution and development of scyphozoan jellyfish. Biol Rev Camb Philos Soc 2018; 93:1228-1250. [DOI: 10.1111/brv.12393] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/08/2017] [Accepted: 12/18/2017] [Indexed: 12/01/2022]
Affiliation(s)
- Rebecca R. Helm
- Woods Hole Oceanographic Institution – Biology, Mailstop 33, 45 Water Street Woods Hole MA 01543 U.S.A
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Bosch TCG, Klimovich A, Domazet-Lošo T, Gründer S, Holstein TW, Jékely G, Miller DJ, Murillo-Rincon AP, Rentzsch F, Richards GS, Schröder K, Technau U, Yuste R. Back to the Basics: Cnidarians Start to Fire. Trends Neurosci 2016; 40:92-105. [PMID: 28041633 DOI: 10.1016/j.tins.2016.11.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 12/15/2022]
Abstract
The nervous systems of cnidarians, pre-bilaterian animals that diverged close to the base of the metazoan radiation, are structurally simple and thus have great potential to reveal fundamental principles of neural circuits. Unfortunately, cnidarians have thus far been relatively intractable to electrophysiological and genetic techniques and consequently have been largely passed over by neurobiologists. However, recent advances in molecular and imaging methods are fueling a renaissance of interest in and research into cnidarians nervous systems. Here, we review current knowledge on the nervous systems of cnidarian species and propose that researchers should seize this opportunity and undertake the study of members of this phylum as strategic experimental systems with great basic and translational relevance for neuroscience.
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Affiliation(s)
| | | | - Tomislav Domazet-Lošo
- Ruđer Bošković Institute, Zagreb, Croatia; Catholic University of Croatia, Zagreb, Croatia
| | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Germany
| | | | - Gáspár Jékely
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - David J Miller
- ARC Centre of Excellence for Coral Reef Studies, Townsville, Australia
| | | | - Fabian Rentzsch
- Sars International Centre for Marine Molecular Biology, University of Bergen, Norway
| | - Gemma S Richards
- Sars International Centre for Marine Molecular Biology, University of Bergen, Norway; University of Queensland, Brisbane, Australia
| | | | | | - Rafael Yuste
- Neurotechnology Center, Columbia University, New York, NY, USA.
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Westlake HE, Page LR. Muscle and nerve net organization in stalked jellyfish (Medusozoa: Staurozoa). J Morphol 2016; 278:29-49. [PMID: 27696494 DOI: 10.1002/jmor.20617] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/21/2016] [Accepted: 09/16/2016] [Indexed: 12/23/2022]
Abstract
Staurozoan cnidarians display an unusual combination of polyp and medusa characteristics and their morphology may be informative about the evolutionary origin of medusae. We studied neuromuscular morphology of two staurozoans, Haliclystus 'sanjuanensis' and Manania handi, using whole mount immunohistochemistry with antibodies against FMRFamide and α-tubulin to label neurons and phalloidin to label muscles. All muscles appeared to lack striations. Longitudinal interradial muscles are probable homologues of stalk muscles in scyphopolyps, but in adult staurozoans they are elaborated to inwardly flex marginal lobes of the calyx during prey capture; these muscles are pennate in M. handi. Manubrial perradial muscles, like the manubrium itself, are an innovation shared with pelagic medusae and manubrial interradial muscles are shared with scyphozoan ephyra. Marginal muscles of M. handi displayed occasional synchronous contraction reminiscent of a medusa swim pulse, but contractions were not repetitive. The nerve net in both species showed regional variation in density and orientation of neurons. Some areas labeled predominantly by α-tubulin antibodies (exumbrellar epidermis), other areas labeled exclusively by FMRFamide antibodies (dense plexus of neurites surrounding the base of secondary tentacles, neuronal concentration at the base of transformed primary tentacles; gastrodermal nerve net), but most areas showed a mix of neurons labeled by these two antibodies and frequent co-labeling of neurons. Transformed primary tentacles had a concentration of FMRFamide-immunoreactive neurons at their base that was associated with a pigment spot in M. handi; this is consistent with their homology with rhopalia of medusae, which are also derived from primary tentacles. The muscular system of these staurozoans embodies characteristics of both scyphopolyps and pelagic medusae. However, their nerve net is more polyp-like, although marginal concentrations of the net associated with primary and secondary tentacles may facilitate the richer behavioral repertoire of staurozoans relative to polyps of other medusozoans. J. Morphol. 278:29-49, 2017. ©© 2016 Wiley Periodicals,Inc.
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Affiliation(s)
- Hannah E Westlake
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, British Columbia, V8W 2Y2, Canada
| | - Louise R Page
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, British Columbia, V8W 2Y2, Canada
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Raikova EV, Raikova OI. Nervous system immunohistochemistry of the parasitic cnidarian Polypodium hydriforme at its free-living stage. ZOOLOGY 2015; 119:143-152. [PMID: 26897553 DOI: 10.1016/j.zool.2015.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/09/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
Abstract
Polypodium hydriforme, the only species in Polypodiozoa, which is currently considered a class of Cnidaria, and likely a sister group to Medusozoa (together with Myxozoa), is a cnidarian adapted to intracellular parasitism inside sturgeon oocytes. Free-living P. hydriforme lives on river bottoms; it walks on supporting tentacles and uses sensory tentacles to capture food and bring it to the mouth. The nervous system of free-living P. hydriforme was studied by confocal microscopy and immunohistochemistry using antibodies to FMRF-amide and α-tubulin combined with phalloidin-staining of F-actin fibres. A sensory FMRF-amide immunoreactive (IR) nerve net and an α-tubulin IR nerve net have been identified. The FMRF-amide IR nerve net underlies the epidermis along the tentacles and around the mouth; it consists of neurites emanating from epidermal sensory cells and basiepidermal ganglion cells, and it connects with cnidocytes. A deeper-lying α-tubulin IR nerve net occurs only in tentacles and looks like chains of different-sized beads crossing the mesoglea and entwining muscles. Anti-α-tubulin staining also reveals microtubules in muscle cells following the longitudinal muscle fibres or the thin circular F-actin fibres of the tentacles. Cnidocytes in the tentacles are embedded in a regular hexagonal non-neural network formed by the tubulin IR cytoskeleton of epidermal cells. Cnidocils of the cnidocytes around the mouth and in walking tentacles are identical, but those in sensory tentacles differ in length and width. The possible homology of the tubulin IR nerve net with motor nerve nets of cnidarians is discussed. The absence of a classic nerve ring around the mouth and the lack of specialised sense organs are considered to be plesiomorphic characters for Cnidaria.
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Affiliation(s)
- Ekaterina V Raikova
- Institute of Cytology, Russian Academy of Sciences, 4, Tikhoretsky ave., 194064 St. Petersburg, Russia
| | - Olga I Raikova
- Zoological Institute, Russian Academy of Sciences, 1, Universitetskaya nab., 199034 St. Petersburg, Russia; Biological Faculty, Saint Petersburg State University, 7-9, Universitetskaya nab., 199034 St. Petersburg, Russia.
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10
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Satterlie RA. The search for ancestral nervous systems: an integrative and comparative approach. ACTA ACUST UNITED AC 2015; 218:612-7. [PMID: 25696824 DOI: 10.1242/jeb.110387] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Even the most basal multicellular nervous systems are capable of producing complex behavioral acts that involve the integration and combination of simple responses, and decision-making when presented with conflicting stimuli. This requires an understanding beyond that available from genomic investigations, and calls for a integrative and comparative approach, where the power of genomic/transcriptomic techniques is coupled with morphological, physiological and developmental experimentation to identify common and species-specific nervous system properties for the development and elaboration of phylogenomic reconstructions. With careful selection of genes and gene products, we can continue to make significant progress in our search for ancestral nervous system organizations.
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Affiliation(s)
- Richard A Satterlie
- Department of Biology and Marine Biology and Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA
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Gold DA, Nakanishi N, Hensley NM, Cozzolino K, Tabatabaee M, Martin M, Hartenstein V, Jacobs DK. Structural and Developmental Disparity in the Tentacles of the Moon Jellyfish Aurelia sp.1. PLoS One 2015; 10:e0134741. [PMID: 26241309 PMCID: PMC4524682 DOI: 10.1371/journal.pone.0134741] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 07/13/2015] [Indexed: 01/13/2023] Open
Abstract
Tentacles armed with stinging cells (cnidocytes) are a defining trait of the cnidarians, a phylum that includes sea anemones, corals, jellyfish, and hydras. While cnidarian tentacles are generally characterized as structures evolved for feeding and defense, significant variation exists between the tentacles of different species, and within the same species across different life stages and/or body regions. Such diversity suggests cryptic distinctions exist in tentacle function. In this paper, we use confocal and transmission electron microscopy to contrast the structure and development of tentacles in the moon jellyfish, Aurelia species 1. We show that polyp oral tentacles and medusa marginal tentacles display markedly different cellular and muscular architecture, as well as distinct patterns of cellular proliferation during growth. Many structural differences between these tentacle types may reflect biomechanical solutions to different feeding strategies, although further work would be required for a precise mechanistic understanding. However, differences in cell proliferation dynamics suggests that the two tentacle forms lack a conserved mechanism of development, challenging the textbook-notion that cnidarian tentacles can be homologized into a conserved bauplan.
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Affiliation(s)
- David A. Gold
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Nagayasu Nakanishi
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Nicholai M. Hensley
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Kira Cozzolino
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Mariam Tabatabaee
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Michelle Martin
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
| | - Volker Hartenstein
- Department of Molecular, Cell, and Developmental Biology. University of California Los Angeles, Los Angeles, California, United States of America
| | - David K. Jacobs
- Department of Ecology and Evolutionary Biolology. University of California Los Angeles, Los Angeles, California, United States of America
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Abstract
The foundation of the diverse metazoan nervous systems is laid by embryonic patterning mechanisms, involving the generation and movement of neural progenitors and their progeny. Here we divide early neurogenesis into discrete elements, including origin, pattern, proliferation, and movement of neuronal progenitors, which are controlled by conserved gene cassettes. We review these neurogenetic mechanisms in representatives of the different metazoan clades, with the goal to build a conceptual framework in which one can ask specific questions, such as which of these mechanisms potentially formed part of the developmental "toolkit" of the bilaterian ancestor and which evolved later.
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Affiliation(s)
- Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Angelika Stollewerk
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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Satterlie RA. Multiple conducting systems in the cubomedusa Carybdea marsupialis. THE BIOLOGICAL BULLETIN 2014; 227:274-284. [PMID: 25572215 DOI: 10.1086/bblv227n3p274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Acute responses to mechanical, electrical, and photic stimuli were used to describe neural conducting systems in the cubomedusan jellyfish Carybdea marsupialis underlying three behaviors: contractile responses of single tentacles, protective crumple responses, and alterations of swimming activity by the visual system. Responses of single tentacles consisted of tentacular shortening and inward pedalial bending, and were accompanied by bursts of extracellularly recorded spike activity that were restricted to the stimulated tentacle. With nociceptive stimuli delivered to the subumbrella or margin, all four tentacles produced similar responses in a crumple response. The spike bursts in all four tentacles showed coordinated firing as long as the nerve ring was intact. Crumples were still produced following cuts through the nerve ring, but the activity in individual tentacles was no longer coordinated. Responses to light-on stimulation of a rhopalium, as recorded from the pacemaker region, were weak and inconsistent, but when present, resulted in a stimulation of swimming activity. In comparison, light-off responses were robust and resulted in temporary inhibition of swimming activity. Light-off responses were conducted in the nerve ring to unstimulated rhopalia. In conclusion, three conducting systems have been described as components of the rhopalia-nerve ring centralized system in Carybdea: the swim motor system, the crumple coordination system, and the light-off response system.
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Affiliation(s)
- Richard A Satterlie
- Department of Biology and Marine Biology and Center for Marine Science, University of North Carolina Wilmington, Wilmington, North Carolina 28403
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14
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Eichinger JM, Satterlie RA. Organization of the ectodermal nervous structures in medusae: cubomedusae. THE BIOLOGICAL BULLETIN 2014; 226:41-55. [PMID: 24648206 DOI: 10.1086/bblv226n1p41] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
At least two conducting systems are well documented in cubomedusae. A variably diffuse network of large neurons innervates the swim musculature and can be visualized immunohistochemically using antibodies against α- or β-tubulin. Despite the non-specificity of these antibodies, multiple lines of evidence suggest that staining highlights the primary motor networks. These networks exhibit unique neurite distributions among the muscle sheets in that network density is greatest in the perradial frenula, where neurites are oriented in parallel with radial muscle fibers. This highly innervated, buttress-like muscle sheet may serve a critical role in the cubomedusan mechanism of turning. In scyphomedusae, a second subumbrellar network immunoreactive to antibodies against the neuropeptide FMRFamide innervates the swim musculature, but it is absent in cubomedusae. Immunoreactivity to FMRFamide in cubomedusae is mostly limited to a small network of neurons in the pacemaker region of the rhopalia, the pedalial apex at the nerve ring junction, and a few neuron tracts in the nerve ring. However, FMRFamide-immunoreactive networks, as well as tubulin-immunoreactive networks, are nearly ubiquitous outside of the swim muscle sheets in the perradial smooth muscle bands, manubrium, pedalia, and tentacles. Here we describe in detail the peripheral nerve nets of box jellyfish on the basis of immunoreactivity to the antibodies above. Our results offer insight into how the peripheral nerve nets are organized to produce the complex swimming, feeding, and defensive behaviors observed in cubomedusae.
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Affiliation(s)
- Justin M Eichinger
- Department of Biology and Marine Biology and Center for Marine Science, University of North Carolina Wilmington, Wilmington, North Carolina 28409
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