Topic
Electric eel
About: Electric eel is a research topic. Over the lifetime, 137 publications have been published within this topic receiving 2860 citations.
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Papers
TL;DR: Experiments throw some light on the nature of the adaptation which has occurred in the electric organ by applying the type of internal microelectrode first developed by Graham & Gerard (1946) to investigate the membrane potentials in the individual electroplates of the electric eel.
Abstract: Ever since Walsh (1773) and Williamson (1775) suggested that the paralysing effect of touching certain fishes was due to an electric discharge, the properties of the electric organ have interested physicists and physiologists alike. It has long been recognized that in most species the electric organ is derived from muscle (Biedermann, 1898), but the exact way in which it has developed has remained in doubt. Several alternative theories have been put forward to explain the mechanism of the discharge (Fessard, 1946), but it has been difficult to decide between them, because the discharge has hitherto been recorded only with externally applied electrodes. Even when fragments of electric organ are used, such experiments cannot reveal the precise site of origin-at the cellular level-of the potential changes. We have therefore applied the type of internal microelectrode first developed by Graham & Gerard (1946), with modifications described by Nastuk & Hodgkin (1950), to investigate the membrane potentials in the individual electroplates of the electric eel, Electrophorus electricus L. Our results, which have already been reported briefly (Keynes & MartinsFerreira, 1952), show that across both faces of the electroplate there is normally a resting potential of the same size and polarity as that observed in other excitable tissues. During activity a large reversed action potential develops across the innervated face, wbile the potential across the nonnervous face remains virtually unaltered. Preliminary studies of the effects of factors such as the external sodium concentration on the sizes of these potentials suggest that they are produced by mechanisms similar to those responsible for the propagated impulse in nerve and muscle fibres. Considered in conjunction with the recent work of Fatt & Katz (1951 a) on the motor endplate, our experiments throw some light on the nature of the adaptation which has occurred in the electric organ.
240 citations
Michigan State University1, University of Wisconsin-Madison2, Harvard University3, Broad Institute4, Rice University5, The Ohio State University Wexner Medical Center6, Texas A&M University7, New Mexico State University8, University of Louisiana at Lafayette9, Marine Biological Laboratory10, University of Texas at Austin11
TL;DR: The results indicate that, despite millions of years of evolution and large differences in the morphology of electric organ cells, independent lineages have leveraged similar transcription factors and developmental and cellular pathways in the evolution of electric organs.
Abstract: Little is known about the genetic basis of convergent traits that originate repeatedly over broad taxonomic scales. The myogenic electric organ has evolved six times in fishes to produce electric fields used in communication, navigation, predation, or defense. We have examined the genomic basis of the convergent anatomical and physiological origins of these organs by assembling the genome of the electric eel (Electrophorus electricus) and sequencing electric organ and skeletal muscle transcriptomes from three lineages that have independently evolved electric organs. Our results indicate that, despite millions of years of evolution and large differences in the morphology of electric organ cells, independent lineages have leveraged similar transcription factors and developmental and cellular pathways in the evolution of electric organs.
200 citations
National Museum of Natural History1, University of Central Florida2, Cornell University3, Federal University of Pará4, Academy of Natural Sciences of Drexel University5, National Institute of Amazonian Research6, Pontifícia Universidade Católica de Minas Gerais7, University of São Paulo8, Anton de Kom University of Suriname9, Universidade Federal de Rondônia10, Museu Paraense Emílio Goeldi11, Federal University of Western Pará12, Federal University of Maranhão13
TL;DR: It is shown that there are three major lineages of Electrophorus distributed across Greater Amazonia and described two new species, one with a much stronger electric discharge than was previously known, making it the strongest living bioelectricity generator.
Abstract: Is there only one electric eel species? For two and a half centuries since its description by Linnaeus, Electrophorus electricus has captivated humankind by its capacity to generate strong electric discharges. Despite the importance of Electrophorus in multiple fields of science, the possibility of additional species-level diversity in the genus, which could also reveal a hidden variety of substances and bioelectrogenic functions, has hitherto not been explored. Here, based on overwhelming patterns of genetic, morphological, and ecological data, we reject the hypothesis of a single species broadly distributed throughout Greater Amazonia. Our analyses readily identify three major lineages that diverged during the Miocene and Pliocene—two of which warrant recognition as new species. For one of the new species, we recorded a discharge of 860 V, well above 650 V previously cited for Electrophorus, making it the strongest living bioelectricity generator. A single species of electric eel, Electrophorus electricus, has been described. Here, de Santana et al. show that there are three major lineages of Electrophorus distributed across Greater Amazonia and describe two new species, one with a much stronger electric discharge than was previously known.
139 citations
TL;DR: Ageing and dealkylation of Soman-inactivated electric eel cholinesterase occur at essentially identical rates and are catalyzed by an acidic group in the enzyme with a pKa′ of 6.4.
129 citations
TL;DR: ACh, ATP, and proteoglycan are common molecular constituents of motor nerve terminal‐derived synaptic vesicles from Torpedo to rat and may play a specific role in the process of cholinergic signal transmission.
Abstract: Cholinergic synaptic vesicles were isolated from the electric organs of the electric eel (Electrophorus electricus) and the electric catfish (Malapterurus electricus) as well as from the diaphragm of the rat by density gradient centrifugation followed by column chromatography on Sephacryl-1000 This was verified by both biochemical and electron microscopic criteria Differences in size between synaptic vesicles from the various tissue sources were reflected by their elution pattern from the Sephacryl column Specific activities of acetylcholine (ACh; in nmol/mg of protein) of chromatography-purified vesicle fractions were 36 (electric eel), 2 (electric catfish), and 1 (rat diaphragm) Synaptic vesicles from all three sources contained ATP in addition to ACh (molar ratios of ACh/ATP, 9-12) as well as binding activity for an antibody raised against Torpedo cholinergic synaptic vesicle proteoglycan Synaptic vesicles from rat diaphragm contained binding activity for the monoclonal antibody asv 48 raised against a rat brain 65-kilodalton synaptic vesicle protein Antibody asv 48 binding was absent from electric eel and electric catfish synaptic vesicles These antibody binding results, which were obtained by a dot blot assay on isolated vesicles, directly correspond to the immunocytochemical results demonstrating fluorescein isothiocyanate staining in the respective nerve terminals Our results imply that ACh, ATP, and proteoglycan are common molecular constituents of motor nerve terminal-derived synaptic vesicles from Torpedo to rat In addition to ACh, both ATP and proteoglycan may play a specific role in the process of cholinergic signal transmission
106 citations
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Performance Metrics
| Year | Papers |
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| 2021 | 2 |
| 2020 | 2 |
| 2019 | 2 |
| 2018 | 2 |
| 2017 | 3 |
| 2015 | 2 |