1
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El-Mansi AA, Rady AM, Ibrahim EH, ElBealy E. Cellular patterning and cyto-architectural organization of the skin of electric catfish (Malapterurus electricus, Siluriformes) with a particular emphasis on its ampullary electroreceptor. ZOOLOGY 2024; 163:126159. [PMID: 38471427 DOI: 10.1016/j.zool.2024.126159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 02/04/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024]
Abstract
The functional morphology of the skin of Malapteruridae is presumably evolved to cope with a diversified range of ambient physiological, environmental, and behavioral conditions. Herein, we firstly characterized the microstructures and intriguing patterning of the skin of twelve adult electric catfish (Malapterurus electricus, Malapteruridae) using histological, histochemical, immunofluorescent, and ELISA standard methodology. The skin comprises three sequentially-oriented layers: the epidermis, dermis, and hypodermis with a significantly increased thickness of the former. The epidermis contains four types of cells: the surface epithelial cells, mucous cells, granular cells, and club cells. We defined distinctive ampullary electroreceptors in the outer epidermis that possess flask-shaped sensory crypt containing electroreceptor cells together with vertical collagen rods. Dermis and hypodermis are composed of connective tissue; however, the former is much more coarse and dense with comparable reactivity for Masson-Goldner trichrome (MT). Placing our data in the context of the limited body of previous work, we showed subtle changes in the expression of mucin subunits together with cytoskeletal fractions of collagens, myosin, F-actin, keratins, and tubulins. Taken as a whole, our results convincingly showed that the skin of M. electricus shares some structural similarities to other Siluriformes, however, it has some functional modifications that are implicated in protection, defense, and foraging behavior.
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Affiliation(s)
- Ahmed A El-Mansi
- Biology Dept., Faculty of Science, King Khalid University, Abha, 61421, Saudi Arabia.
| | - Ahmed M Rady
- Biology Dept., Faculty of Science, King Saud University, Riyadh, Saudi Arabia
| | - Esam H Ibrahim
- Biology Dept., Faculty of Science, King Khalid University, Abha, 61421, Saudi Arabia
| | - Eman ElBealy
- Biology Dept., Faculty of Science, King Khalid University, Abha, 61421, Saudi Arabia
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2
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Muller SZ, Abbott LF, Sawtell NB. A mechanism for differential control of axonal and dendritic spiking underlying learning in a cerebellum-like circuit. Curr Biol 2023; 33:2657-2667.e4. [PMID: 37311457 PMCID: PMC10524478 DOI: 10.1016/j.cub.2023.05.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/06/2023] [Accepted: 05/17/2023] [Indexed: 06/15/2023]
Abstract
In addition to the action potentials used for axonal signaling, many neurons generate dendritic "spikes" associated with synaptic plasticity. However, in order to control both plasticity and signaling, synaptic inputs must be able to differentially modulate the firing of these two spike types. Here, we investigate this issue in the electrosensory lobe (ELL) of weakly electric mormyrid fish, where separate control over axonal and dendritic spikes is essential for the transmission of learned predictive signals from inhibitory interneurons to the output stage of the circuit. Through a combination of experimental and modeling studies, we uncover a novel mechanism by which sensory input selectively modulates the rate of dendritic spiking by adjusting the amplitude of backpropagating axonal action potentials. Interestingly, this mechanism does not require spatially segregated synaptic inputs or dendritic compartmentalization but relies instead on an electrotonically distant spike initiation site in the axon-a common biophysical feature of neurons.
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Affiliation(s)
- Salomon Z Muller
- Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - L F Abbott
- Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY 10027, USA; Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10027, USA
| | - Nathaniel B Sawtell
- Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY 10027, USA.
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3
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Kumar V, Yu C, McGinn CK, Perks KE, Thompson SM, Sawtell NB, Kymissis I. A Dense Conformal Electrode Array for High Spatial Resolution Stimulation of Electrosensory Systems. ADVANCED MATERIALS TECHNOLOGIES 2023; 8:2200354. [PMID: 37007916 PMCID: PMC10062704 DOI: 10.1002/admt.202200354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Indexed: 06/19/2023]
Abstract
Studies of electrosensory systems have led to insights into to a number of general issues in biology. However, investigations of these systems have been limited by the inability to precisely control spatial patterns of electrosensory input. In this paper, an electrode array and a system to selectively stimulate spatially restricted regions of an electroreceptor array is presented. The array has 96 channels consisting of chrome/gold electrodes patterned on a flexible parylene-C substrate and encapsulated with another parylene-C layer. The conformability of the electrode array allows for optimal current driving and surface interface conditions. Recordings of neural activity at the first central processing stage in weakly electric mormyrid fish support the potential of this system for high spatial resolution stimulation and mapping of electrosensory systems.
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Affiliation(s)
- Vikrant Kumar
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Caroline Yu
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Christine K McGinn
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Krista E Perks
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Sarah M Thompson
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Nathaniel B Sawtell
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Ioannis Kymissis
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
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4
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Welzel G, Schuster S. Electric catfish hearts are not intrinsically immune to electric shocks. J Exp Biol 2022; 225:276258. [PMID: 35946177 DOI: 10.1242/jeb.244307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 07/19/2022] [Indexed: 10/15/2022]
Abstract
High voltage electric shocks cause life threatening cardiac injuries such as sudden cardiac standstill or severe myocardial injury. Here, we analysed the physiology of the heart of the strongly electric catfish (Malapterurus beninensis) that stuns prey with high-voltage shocks but is immune to its own, as well as external, high-voltage shocks. Neither a detailed analysis of the electrocardiogram nor the structure of the heart indicated a specialized cardiac conduction system. Using a suitable perfusion system, we discovered that, despite its immunity in vivo, the explanted heart of electric catfish can readily be activated by external electrical currents and is equally sensitive to electric shock-induced arrhythmias as similar-sized goldfish hearts. The surprise thus is that the electric catfish has a vulnerable heart that requires to be protected by highly efficient but presently unknown means.
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Affiliation(s)
- Georg Welzel
- Department of Animal Physiology, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| | - Stefan Schuster
- Department of Animal Physiology, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
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5
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Neurobiology: The power of pauses in electrocommunication. Curr Biol 2021; 31:R900-R901. [PMID: 34314716 DOI: 10.1016/j.cub.2021.06.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new study of social communication behavior in weakly electric fish identifies neural mechanisms that may account for the significance of silent pauses in communication.
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6
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Wang Y, Yang L. Genomic Evidence for Convergent Molecular Adaptation in Electric Fishes. Genome Biol Evol 2021; 13:6151746. [PMID: 33638979 PMCID: PMC7952227 DOI: 10.1093/gbe/evab038] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2021] [Indexed: 12/13/2022] Open
Abstract
Fishes have independently evolved electric organs (EOs) at least six times, and the electric fields are used for communication, defense, and predation. However, the genetic basis of convergent evolution of EOs remains unclear. In this study, we conducted comparative genomic analyses to detect genes showing signatures of positive selection and convergent substitutions in electric fishes from three independent lineages (Mormyroidea, Siluriformes, and Gymnotiformes). Analysis of 4,657 orthologs between electric fishes and their corresponding control groups identified consistent evidence for accelerated evolution in electric fish lineages. A total of 702 positively selected genes (PSGs) were identified in electric fishes, and many of these genes corresponded to cell membrane structure, ion channels, and transmembrane transporter activity. Comparative genomic analyses revealed that widespread convergent amino acid substitutions occurred along the electric fish lineages. The overlap of convergent genes and PSGs was identified as adaptive convergence, and a subset of genes was putatively associated with electrical and muscular activities, especially scn4aa (a voltage-gated sodium channel gene). Our results provide hints to the genetic basis for the independent evolution of EOs during millions of years of evolution.
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Affiliation(s)
- Ying Wang
- College of Life Sciences, Jianghan University, Wuhan, 430056, China
| | - Liandong Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
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7
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Welzel G, Schuster S. Efficient high-voltage protection in the electric catfish. J Exp Biol 2021; 224:jeb.239855. [PMID: 33462134 DOI: 10.1242/jeb.239855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/24/2020] [Indexed: 11/20/2022]
Abstract
For thousands of years, starting with detailed accounts from ancient Egypt, the African electric catfish (Malapteruridae) has been renowned for its ability to hunt and to defend itself with powerful electric shocks. Surprisingly, the degree to which electric catfish are protected against their own or external electric shocks, how specific any protection would be to the species-specific waveform and whether a discharging catfish has to actively prepare for the onset of its high-voltage discharges has never been analysed. Here, we used digital high-speed video to record catfish during their own discharges or as they were exposed to external discharges, employing goldfish to carefully calibrate the efficiency of all discharges. Electric catfish show a remarkable degree of protection against high voltages: both self-produced and external electric shocks that heavily affected control goldfish failed to evoke involuntary muscle contraction or to affect sensorimotor processing. Even a commercial electrofishing device, set to efficiently immobilise and narcotise fish, failed to have any effect on the electric catfish. Our findings rule out several protective mechanisms and demonstrate a highly efficient and versatile shielding whose nature is presently unclear.
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Affiliation(s)
- Georg Welzel
- Department of Animal Physiology, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| | - Stefan Schuster
- Department of Animal Physiology, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
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8
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Alshami IJJ, Ono Y, Correia A, Hacker C, Lange A, Scholpp S, Kawasaki M, Ingham PW, Kudoh T. Development of the electric organ in embryos and larvae of the knifefish, Brachyhypopomus gauderio. Dev Biol 2020; 466:99-108. [PMID: 32687892 PMCID: PMC7507958 DOI: 10.1016/j.ydbio.2020.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 06/04/2020] [Accepted: 06/23/2020] [Indexed: 11/05/2022]
Abstract
South American Gymnotiform knifefish possess electric organs that generate electric fields for electro-location and electro-communication. Electric organs in fish can be derived from either myogenic cells (myogenic electric organ/mEO) or neurogenic cells (neurogenic electric organ/nEO). To date, the embryonic development of EOs has remained obscure. Here we characterize the development of the mEO in the Gymnotiform bluntnose knifefish, Brachyhypopomus gauderio. We find that EO primordial cells arise during embryonic stages in the ventral edge of the tail myotome, translocate into the ventral fin and develop into syncytial electrocytes at early larval stages. We also describe a pair of thick nerve cords that flank the dorsal aorta, the location and characteristic morphology of which are reminiscent of the nEO in Apteronotid species, suggesting a common evolutionary origin of these tissues. Taken together, our findings reveal the embryonic origins of the mEO and provide a basis for elucidating the mechanisms of evolutionary diversification of electric charge generation by myogenic and neurogenic EOs. Developmental staging of the electric bluntnose knifefish, Brachyhypopomus gauderio embryos and larvae. The primordia of the myogenic electric organ originate in the ventral somite, migrate in the ventral fin and develop to the electric organ. Evolutionary conservation between the nerve codes in the B. gauderio and the neurogenic electric organs in the Apteronotidae.
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Affiliation(s)
- Ilham J J Alshami
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Yosuke Ono
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK; Living Systems Institute, University of Exeter, Exeter, EX4 4QD, UK
| | - Ana Correia
- Department of Physiology, Development and Neuroscience, University of Cambridge, CB2 3EG, UK
| | - Christian Hacker
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Anke Lange
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Steffen Scholpp
- Living Systems Institute, University of Exeter, Exeter, EX4 4QD, UK
| | - Masashi Kawasaki
- Department of Biology, University of Virginia, Charlottesville, VA, 22904, USA
| | - Philip W Ingham
- Living Systems Institute, University of Exeter, Exeter, EX4 4QD, UK; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Tetsuhiro Kudoh
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK.
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9
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Elbassiouny AA, Lovejoy NR, Chang BSW. Convergent patterns of evolution of mitochondrial oxidative phosphorylation (OXPHOS) genes in electric fishes. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190179. [PMID: 31787042 PMCID: PMC6939368 DOI: 10.1098/rstb.2019.0179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2019] [Indexed: 12/26/2022] Open
Abstract
The ability to generate and detect electric fields has evolved in several groups of fishes as a means of communication, navigation and, occasionally, predation. The energetic burden required can account for up to 20% of electric fishes' daily energy expenditure. Despite this, molecular adaptations that enable electric fishes to meet the metabolic demands of bioelectrogenesis remain unknown. Here, we investigate the molecular evolution of the mitochondrial oxidative phosphorylation (OXPHOS) complexes in the two most diverse clades of weakly electric fishes-South American Gymnotiformes and African Mormyroidea, using codon-based likelihood approaches. Our analyses reveal that although mitochondrial OXPHOS genes are generally subject to strong purifying selection, this constraint is significantly reduced in electric compared to non-electric fishes, particularly for complexes IV and V. Moreover, analyses of concatenated mitochondrial genes show strong evidence for positive selection in complex I genes on the two branches associated with the independent evolutionary origins of electrogenesis. These results suggest that adaptive evolution of proton translocation in the OXPHOS cellular machinery may be associated with the evolution of bioelectrogenesis. Overall, we find striking evidence for remarkably similar effects of electrogenesis on the molecular evolution of mitochondrial OXPHOS genes in two independently derived clades of electrogenic fishes. This article is part of the theme issue 'Linking the mitochondrial genotype to phenotype: a complex endeavour'.
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Affiliation(s)
- Ahmed A. Elbassiouny
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Scarborough, Ontario, Canada
| | - Nathan R. Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Scarborough, Ontario, Canada
| | - Belinda S. W. Chang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
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10
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O'Rourke DP, Baccanale CL, Stoskopf MK. Nontraditional Laboratory Animal Species (Cephalopods, Fish, Amphibians, Reptiles, and Birds). ILAR J 2019; 59:168-176. [PMID: 30462255 DOI: 10.1093/ilar/ily003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/18/2018] [Indexed: 12/27/2022] Open
Abstract
Aquatic vertebrates and cephalopods, amphibians, reptiles, and birds offer unique safety and occupational health challenges for laboratory animal personnel. This paper discusses environmental, handling, and zoonotic concerns associated with these species.
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Affiliation(s)
- Dorcas P O'Rourke
- Dorcas P. O'Rourke, DVM, MS, DACLAM, is Professor and Chair of the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Cecile L. Baccanale, DVM, is Associate Professor in the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Michael K. Stoskopf, DVM, PhD, DACZM, is Professor in the Department of Clinical Sciences, at the College of Veterinary Medicine as well as the Colleges of Natural Resources, Science, and Engineering at North Carolina State University in Raleigh, North Carolina
| | - Cecile L Baccanale
- Dorcas P. O'Rourke, DVM, MS, DACLAM, is Professor and Chair of the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Cecile L. Baccanale, DVM, is Associate Professor in the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Michael K. Stoskopf, DVM, PhD, DACZM, is Professor in the Department of Clinical Sciences, at the College of Veterinary Medicine as well as the Colleges of Natural Resources, Science, and Engineering at North Carolina State University in Raleigh, North Carolina
| | - Michael K Stoskopf
- Dorcas P. O'Rourke, DVM, MS, DACLAM, is Professor and Chair of the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Cecile L. Baccanale, DVM, is Associate Professor in the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Michael K. Stoskopf, DVM, PhD, DACZM, is Professor in the Department of Clinical Sciences, at the College of Veterinary Medicine as well as the Colleges of Natural Resources, Science, and Engineering at North Carolina State University in Raleigh, North Carolina
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11
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Huang CG, Metzen MG, Chacron MJ. Descending pathways mediate adaptive optimized coding of natural stimuli in weakly electric fish. SCIENCE ADVANCES 2019; 5:eaax2211. [PMID: 31693006 PMCID: PMC6821470 DOI: 10.1126/sciadv.aax2211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Biological systems must be flexible to environmental changes to survive. This is exemplified by the fact that sensory systems continuously adapt to changes in the environment to optimize coding and behavioral responses. However, the nature of the underlying mechanisms remains poorly understood in general. Here, we investigated the mechanisms mediating adaptive optimized coding of naturalistic stimuli with varying statistics depending on the animal's velocity during movement. We found that central neurons adapted their responses to stimuli with different power spectral densities such as to optimally encode them, thereby ensuring that behavioral responses are, in turn, better matched to the new stimulus statistics. Sensory adaptation further required descending inputs from the forebrain as well as the raphe nuclei. Our findings thus reveal a previously unknown functional role for descending pathways in mediating adaptive optimized coding of natural stimuli that is likely generally applicable across sensory systems and species.
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Ching B, Woo JM, Hiong KC, Boo MV, Wong WP, Chew SF, Ip YK. Voltage-Gated Na+ Channel Isoforms and Their mRNA Expression Levels and Protein Abundance in Three Electric Organs and the Skeletal Muscle of the Electric Eel Electrophorus electricus. PLoS One 2016; 11:e0167589. [PMID: 27907137 PMCID: PMC5132174 DOI: 10.1371/journal.pone.0167589] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/16/2016] [Indexed: 11/18/2022] Open
Abstract
This study aimed to obtain the coding cDNA sequences of voltage-gated Na+ channel (scn) α-subunit (scna) and β-subunit (scnb) isoforms from, and to quantify their transcript levels in, the main electric organ (EO), Hunter's EO, Sach's EO and the skeletal muscle (SM) of the electric eel, Electrophorus electricus, which can generate both high and low voltage electric organ discharges (EODs). The full coding sequences of two scna (scn4aa and scn4ab) and three scnb (scn1b, scn2b and scn4b) were identified for the first time (except scn4aa) in E. electricus. In adult fish, the scn4aa transcript level was the highest in the main EO and the lowest in the Sach's EO, indicating that it might play an important role in generating high voltage EODs. For scn4ab/Scn4ab, the transcript and protein levels were unexpectedly high in the EOs, with expression levels in the main EO and the Hunter's EO comparable to those of scn4aa. As the key domains affecting the properties of the channel were mostly conserved between Scn4aa and Scn4ab, Scn4ab might play a role in electrogenesis. Concerning scnb, the transcript level of scn4b was much higher than those of scn1b and scn2b in the EOs and the SM. While the transcript level of scn4b was the highest in the main EO, protein abundance of Scn4b was the highest in the SM. Taken together, it is unlikely that Scna could function independently to generate EODs in the EOs as previously suggested. It is probable that different combinations of Scn4aa/Scn4ab and various Scnb isoforms in the three EOs account for the differences in EODs produced in E. electricus. In general, the transcript levels of various scn isoforms in the EOs and the SM were much higher in adult than in juvenile, and the three EOs of the juvenile fish could be functionally indistinct.
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Affiliation(s)
- Biyun Ching
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Republic of Singapore
| | - Jia M. Woo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Republic of Singapore
| | - Kum C. Hiong
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Republic of Singapore
| | - Mel V. Boo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Republic of Singapore
| | - Wai P. Wong
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Republic of Singapore
| | - Shit F. Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Republic of Singapore
| | - Yuen K. Ip
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Republic of Singapore
- The Tropical Marine Science Institute, National University of Singapore, Kent Ridge, Republic of Singapore
- * E-mail:
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13
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Ching B, Woo JM, Hiong KC, Boo MV, Choo CYL, Wong WP, Chew SF, Ip YK. Na+/K+-ATPase α-subunit (nkaα) isoforms and their mRNA expression levels, overall Nkaα protein abundance, and kinetic properties of Nka in the skeletal muscle and three electric organs of the electric eel, Electrophorus electricus. PLoS One 2015; 10:e0118352. [PMID: 25793901 PMCID: PMC4368207 DOI: 10.1371/journal.pone.0118352] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/14/2015] [Indexed: 11/18/2022] Open
Abstract
This study aimed to obtain the coding cDNA sequences of Na+/K+-ATPase α (nkaα) isoforms from, and to quantify their mRNA expression in, the skeletal muscle (SM), the main electric organ (EO), the Hunter’s EO and the Sach’s EO of the electric eel, Electrophorus electricus. Four nkaα isoforms (nkaα1c1, nkaα1c2, nkaα2 and nkaα3) were obtained from the SM and the EOs of E. electricus. Based on mRNA expression levels, the major nkaα expressed in the SM and the three EOs of juvenile and adult E. electricus were nkaα1c1 and nkaα2, respectively. Molecular characterization of the deduced Nkaα1c1 and Nkaα2 sequences indicates that they probably have different affinities to Na+ and K+. Western blotting demonstrated that the protein abundance of Nkaα was barely detectable in the SM, but strongly detected in the main and Hunter’s EOs and weakly in the Sach’s EO of juvenile and adult E. electricus. These results corroborate the fact that the main EO and Hunter’s EO have high densities of Na+ channels and produce high voltage discharges while the Sach’s EO produces low voltage discharges. More importantly, there were significant differences in kinetic properties of Nka among the three EOs of juvenile E. electricus. The highest and lowest Vmax of Nka were detected in the main EO and the Sach’s EO, respectively, with the Hunter’s EO having a Vmax value intermediate between the two, indicating that the metabolic costs of EO discharge could be the highest in the main EO. Furthermore, the Nka from the main EO had the lowest Km (or highest affinity) for Na+ and K+ among the three EOs, suggesting that the Nka of the main EO was more effective than those of the other two EOs in maintaining intracellular Na+ and K+ homeostasis and in clearing extracellular K+ after EO discharge.
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Affiliation(s)
- Biyun Ching
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Jia M. Woo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Kum C. Hiong
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Mel V. Boo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Celine Y. L. Choo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Wai P. Wong
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Shit F. Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Republic of Singapore
| | - Yuen K. Ip
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
- The Tropical Marine Science Institute, National University of Singapore, Kent Ridge, Singapore, 119227, Republic of Singapore
- * E-mail:
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14
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Lewicki MS, Olshausen BA, Surlykke A, Moss CF. Scene analysis in the natural environment. Front Psychol 2014; 5:199. [PMID: 24744740 PMCID: PMC3978336 DOI: 10.3389/fpsyg.2014.00199] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 02/20/2014] [Indexed: 12/21/2022] Open
Abstract
The problem of scene analysis has been studied in a number of different fields over the past decades. These studies have led to important insights into problems of scene analysis, but not all of these insights are widely appreciated, and there remain critical shortcomings in current approaches that hinder further progress. Here we take the view that scene analysis is a universal problem solved by all animals, and that we can gain new insight by studying the problems that animals face in complex natural environments. In particular, the jumping spider, songbird, echolocating bat, and electric fish, all exhibit behaviors that require robust solutions to scene analysis problems encountered in the natural environment. By examining the behaviors of these seemingly disparate animals, we emerge with a framework for studying scene analysis comprising four essential properties: (1) the ability to solve ill-posed problems, (2) the ability to integrate and store information across time and modality, (3) efficient recovery and representation of 3D scene structure, and (4) the use of optimal motor actions for acquiring information to progress toward behavioral goals.
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Affiliation(s)
- Michael S Lewicki
- Department of Electrical Engineering and Computer Science, Case Western Reserve University Cleveland, OH, USA
| | - Bruno A Olshausen
- Helen Wills Neuroscience Institute, School of Optometry, Redwood Center for Theoretical Neuroscience, University of California at Berkeley Berkeley, CA, USA
| | | | - Cynthia F Moss
- Department of Psychology and Institute for Systems Research, University of Maryland College Park, MD, USA
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