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Escuer P, Guirao-Rico S, Arnedo MA, Sánchez-Gracia A, Rozas J. Population Genomics of Adaptive Radiations: Exceptionally High Levels of Genetic Diversity and Recombination in an Endemic Spider From the Canary Islands. Mol Ecol 2024:e17547. [PMID: 39400446 DOI: 10.1111/mec.17547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 08/26/2024] [Accepted: 09/24/2024] [Indexed: 10/15/2024]
Abstract
The spider genus Dysdera has undergone a remarkable diversification in the oceanic archipelago of the Canary Islands, with ~60 endemic species having originated during the 20 million years since the origin of the archipelago. This evolutionary radiation has been accompanied by substantial dietary shifts, often characterised by phenotypic modifications encompassing morphological, metabolic and behavioural changes. Hence, these endemic spiders represent an excellent model for understanding the evolutionary drivers and to pinpoint the genomic determinants underlying adaptive radiations. Recently, we achieved the first chromosome-level genome assembly of one of the endemic species, D. silvatica, providing a high-quality reference sequence for evolutionary genomics studies. Here, we conducted a low coverage-based resequencing study of a natural population of D. silvatica from La Gomera island. Taking advantage of the new high-quality genome, we characterised genome-wide levels of nucleotide polymorphism, divergence and linkage disequilibrium, and inferred the demographic history of this population. We also performed comprehensive genome-wide scans for recent positive selection. Our findings uncovered exceptionally high levels of nucleotide diversity and recombination in this geographically restricted endemic species, indicative of large historical effective population sizes. We also identified several candidate genomic regions that are potentially under positive selection, highlighting relevant biological processes, such as vision and nitrogen extraction as potential adaptation targets. These processes may ultimately drive species diversification in this genus. This pioneering study of spiders that are endemic to an oceanic archipelago lays the groundwork for broader population genomics analyses aimed at understanding the genetic mechanisms driving adaptive radiation in island ecosystems.
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Affiliation(s)
- Paula Escuer
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Sara Guirao-Rico
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Miquel A Arnedo
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
- Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Barcelona, Spain
| | - Alejandro Sánchez-Gracia
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Julio Rozas
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
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Liu H, Jang J, French AS, Torkkeli PH. Sequence analysis, homology modeling, tissue expression, and potential functions of seven putative acetylcholinesterases in the spider Cupiennius salei. Eur J Neurosci 2024; 60:5785-5811. [PMID: 39230060 DOI: 10.1111/ejn.16524] [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: 06/06/2024] [Revised: 07/30/2024] [Accepted: 08/15/2024] [Indexed: 09/05/2024]
Abstract
Acetylcholine esterases (AChEs) are essential enzymes in cholinergic synapses, terminating neurotransmission by hydrolysing acetylcholine. While membrane bound AChEs at synaptic clefts efficiently perform this task, soluble AChEs are less stable and effective, but function over broader areas. In vertebrates, a single gene produces alternatively spliced forms of AChE, whereas invertebrates often have multiple genes, producing both enzyme types. Despite their significance as pesticide targets, the physiological roles of invertebrate AChEs remain unclear. Here, we characterized seven putative AChEs in the wandering spider, Cupiennius salei, a model species for neurophysiological studies. Sequence analyses and homology modeling predicted CsAChE7 as the sole stable, membrane-bound enzyme functioning at synaptic clefts, while the others are likely soluble enzymes. In situ hybridization of sections from the spider's nervous system revealed CsAChE7 transcripts co-localizing with choline acetyltransferase in cells that also exhibited AChE activity. CsAChE7 transcripts were also found in rapidly adapting mechanosensory neurons, suggesting a role in precise and transient activation of postsynaptic cells, contrasting with slowly adapting, also cholinergic, neurons expressing only soluble AChEs, which allow prolonged activation of postsynaptic cells. These findings suggest that cholinergic transmission is influenced not only by postsynaptic receptors but also by the enzymatic properties regulating acetylcholine clearance. We also show that acetylcholine is a crucial neurotransmitter in the spider's visual system and sensory and motor pathways, but absent in excitatory motor neurons at neuromuscular junctions, consistent with other arthropods. Our findings on sequence structures may have implications for the development of neurological drugs and pesticides.
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Affiliation(s)
- Hongxia Liu
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Jinwon Jang
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Andrew S French
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Päivi H Torkkeli
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
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Artiushin G, Corver A, Gordus A. A three-dimensional immunofluorescence atlas of the brain of the hackled-orb weaver spider, Uloborus diversus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.05.611298. [PMID: 39314479 PMCID: PMC11418967 DOI: 10.1101/2024.09.05.611298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Spider orb-web building is a captivating, rare example of animal construction, whose neural underpinnings remain undiscovered. An essential step in understanding the basis of this behavior is a foundational mapping of the spider's neuroanatomy, which has thus far been primarily studied using non-web building species. We created a three-dimensional atlas for the hackled orb-weaver, Uloborus diversus, based on immunostaining for the presynaptic component, synapsin, in whole-mounted spider synganglia. Aligned to this volume, we examined the expression patterns of neuronal populations representing many of the classical neurotransmitter and neuromodulators, as well as a subset of neuropeptides - detailing immunoreactivity in an unbiased fashion throughout the synganglion, revealing co-expression in known structures, as well as novel neuropils not evident in prior spider works. This optically-sliced, whole-mount atlas is the first of its kind for spiders, representing a substantive addition to knowledge of brain anatomy and neurotransmitter expression patterns for an orb-weaving species.
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Affiliation(s)
| | - Abel Corver
- Department of Biology, Lund University, Lund, Sweden
- Johns Hopkins Kavli Neuroscience Discovery Institute
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD
| | - Andrew Gordus
- Department of Biology, Johns Hopkins University, Baltimore, MD
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD
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De Agrò M, Rößler DC, Shamble PS. Eye-specific detection and a multi-eye integration model of biological motion perception. J Exp Biol 2024; 227:jeb247061. [PMID: 38752337 PMCID: PMC11418026 DOI: 10.1242/jeb.247061] [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: 11/21/2023] [Accepted: 05/07/2024] [Indexed: 06/27/2024]
Abstract
'Biological motion' refers to the distinctive kinematics observed in many living organisms, where visually perceivable points on the animal move at fixed distances from each other. Across the animal kingdom, many species have developed specialized visual circuitry to recognize such biological motion and to discriminate it from other patterns. Recently, this ability has been observed in the distributed visual system of jumping spiders. These eight-eyed animals use six eyes to perceive motion, while the remaining two (the principal anterior medial eyes) are shifted across the visual scene to further inspect detected objects. When presented with a biologically moving stimulus and a random one, jumping spiders turn to face the latter, clearly demonstrating the ability to discriminate between them. However, it remains unclear whether the principal eyes are necessary for this behavior, whether all secondary eyes can perform this discrimination, or whether a single eye-pair is specialized for this task. Here, we systematically tested the ability of jumping spiders to discriminate between biological and random visual stimuli by testing each eye-pair alone. Spiders were able to discriminate stimuli only when the anterior lateral eyes were unblocked, and performed at chance levels in other configurations. Interestingly, spiders showed a preference for biological motion over random stimuli - unlike in past work. We therefore propose a new model describing how specialization of the anterior lateral eyes for detecting biological motion contributes to multi-eye integration in this system. This integration generates more complex behavior through the combination of simple, single-eye responses. We posit that this in-built modularity may be a solution to the limited resources of these invertebrates' brains, constituting a novel approach to visual processing.
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Affiliation(s)
- Massimo De Agrò
- Faculty of Biology, University of Regensburg, 93053 Regensburg, Germany
- Department of Biology, University of Florence, 50121 Firenze, Italy
- The BioRobotics Institute, Sant'Anna School of Advanced Studies, 56127 Pisa, Italy
| | - Daniela C. Rößler
- Zukunftskolleg, Konstanz University, 78464 Konstanz, Germany
- Department of Biology, Konstanz University, 78464 Konstanz, Germany
- Department of Ecology of Animal Societies, Max Planck Institute of Animal Behavior, 78464 Konstanz, Germany
| | - Paul S. Shamble
- Kavli Institute for Neuroscience, Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
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Wang K, Wang J, Liang B, Chang J, Zhu Y, Chen J, Agnarsson I, Li D, Peng Y, Liu J. Eyeless cave-dwelling Leptonetela spiders still rely on light. SCIENCE ADVANCES 2023; 9:eadj0348. [PMID: 38117895 PMCID: PMC10732526 DOI: 10.1126/sciadv.adj0348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 11/17/2023] [Indexed: 12/22/2023]
Abstract
Subterranean animals living in perpetual darkness may maintain photoresponse. However, the evolutionary processes behind the conflict between eye loss and maintenance of the photoresponse remain largely unknown. We used Leptonetela spiders to investigate the driving forces behind the maintenance of the photoresponse in cave-dwelling spiders. Our behavioral experiments showed that all eyeless/reduced-eyed cave-dwelling species retained photophobic response and that they had substantially decreased survival at cave entrances due to weak drought resistance. The transcriptomic analysis demonstrated that nearly all phototransduction pathway genes were present and that all tested phototransduction pathway genes were subjected to strong functional constraints in cave-dwelling species. Our results suggest that cave-dwelling eyeless spiders still use light and that light detection likely plays a role in avoiding the cave entrance habitat. This study confirms that some eyeless subterranean animals have retained their photosensitivity due to natural selection and provides a case of mismatch between phenotype and genotype or physiological function in a long-term evolutionary process.
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Affiliation(s)
- Kai Wang
- The State Key Laboratory of Biocatalysis and Enzyme Engineering of China, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Jinhui Wang
- The State Key Laboratory of Biocatalysis and Enzyme Engineering of China, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Bing Liang
- The State Key Laboratory of Biocatalysis and Enzyme Engineering of China, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Jian Chang
- The State Key Laboratory of Biocatalysis and Enzyme Engineering of China, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Yang Zhu
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Jian Chen
- The State Key Laboratory of Biocatalysis and Enzyme Engineering of China, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Ingi Agnarsson
- Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 102 Reykjavik, Iceland
| | - Daiqin Li
- The State Key Laboratory of Biocatalysis and Enzyme Engineering of China, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Yu Peng
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Jie Liu
- The State Key Laboratory of Biocatalysis and Enzyme Engineering of China, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, Hubei 430062, China
- School of Nuclear Technology and Chemistry and Biology, Hubei University of Science and Technology, Xianning, Hubei 437100, China
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Steinhoff POM, Harzsch S, Uhl G. Comparative neuroanatomy of the central nervous system in web-building and cursorial hunting spiders. J Comp Neurol 2023; 532:e25554. [PMID: 37948052 DOI: 10.1002/cne.25554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 09/01/2023] [Accepted: 10/17/2023] [Indexed: 11/12/2023]
Abstract
Spiders (Araneae) include cursorial species that stalk their prey and more stationary species that use webs for prey capture. While many cursorial hunting spiders rely on visual cues, web-building spiders use vibratory cues (mechanosensation) for prey capture. We predicted that the differences in primary sensory input between the species are mirrored by differences in the morphology/architecture of the central nervous system (CNS). Here, we investigated the CNS anatomy of four spider species, two cursorial hunters Pardosa amentata (Lycosidae) and Marpissa muscosa (Salticidae), and two web-building hunters Argiope bruennichi (Araneidae) and Parasteatoda tepidariorum (Theridiidae). Their CNS was analyzed using Bodian silver impregnations, immunohistochemistry, and microCT analysis. We found that there are major differences between species in the secondary eye pathway of the brain that pertain to first-order, second-order, and higher order brain centers (mushroom bodies [MB]). While P. amentata and M. muscosa have prominent visual neuropils and MB, these are much reduced in the two web-building species. Argiope bruennichi lacks second-order visual neuropils but has specialized photoreceptors that project into two distinct visual neuropils, and P. tepidariorum lacks MB, suggesting that motion vision might be absent in this species. Interestingly, the differences in the ventral nerve cord are much less pronounced, but the web-building spiders have proportionally larger leg neuropils than the cursorial spiders. Our findings suggest that the importance of visual information is much reduced in web-building spiders, compared to cursorial spiders, while processing of mechanosensory information requires the same major circuits in both web-building and cursorial hunting spiders.
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Affiliation(s)
- Philip O M Steinhoff
- Zoological Institute and Museum, General and Systematic Zoology, University of Greifswald, Greifswald, Germany
| | - Steffen Harzsch
- Zoological Institute and Museum, Cytology and Evolutionary Biology, University of Greifswald, Greifswald, Germany
| | - Gabriele Uhl
- Zoological Institute and Museum, General and Systematic Zoology, University of Greifswald, Greifswald, Germany
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Ortega-Escobar J, Hebets EA, Bingman VP, Wiegmann DD, Gaffin DD. Comparative biology of spatial navigation in three arachnid orders (Amblypygi, Araneae, and Scorpiones). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023:10.1007/s00359-023-01612-2. [PMID: 36781447 DOI: 10.1007/s00359-023-01612-2] [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: 09/27/2022] [Revised: 01/07/2023] [Accepted: 01/10/2023] [Indexed: 02/15/2023]
Abstract
From both comparative biology and translational research perspectives, there is escalating interest in understanding how animals navigate their environments. Considerable work is being directed towards understanding the sensory transduction and neural processing of environmental stimuli that guide animals to, for example, food and shelter. While much has been learned about the spatial orientation behavior, sensory cues, and neurophysiology of champion navigators such as bees and ants, many other, often overlooked animal species possess extraordinary sensory and spatial capabilities that can broaden our understanding of the behavioral and neural mechanisms of animal navigation. For example, arachnids are predators that often return to retreats after hunting excursions. Many of these arachnid central-place foragers are large and highly conducive to scientific investigation. In this review we highlight research on three orders within the Class Arachnida: Amblypygi (whip spiders), Araneae (spiders), and Scorpiones (scorpions). For each, we describe (I) their natural history and spatial navigation, (II) how they sense the world, (III) what information they use to navigate, and (IV) how they process information for navigation. We discuss similarities and differences among the groups and highlight potential avenues for future research.
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Affiliation(s)
| | - Eileen A Hebets
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Verner P Bingman
- Department of Psychology and J. P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, OH, 43403, USA
| | - Daniel D Wiegmann
- Department of Biological Sciences and J. P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, OH, 43403, USA
| | - Douglas D Gaffin
- Department of Biology, University of Oklahoma, Norman, OK, 73019, USA
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Friedrich M. Coming into clear sight at last: Ancestral and derived events during chelicerate visual system development. Bioessays 2022; 44:e2200163. [DOI: 10.1002/bies.202200163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Markus Friedrich
- Department of Biological Sciences Wayne State University Detroit Michigan USA
- Department of Ophthalmological, Visual, and Anatomical Sciences, Wayne State University School of Medicine Detroit Michigan USA
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Brenneis G. The visual pathway in sea spiders (Pycnogonida) displays a simple serial layout with similarities to the median eye pathway in horseshoe crabs. BMC Biol 2022; 20:27. [PMID: 35086529 PMCID: PMC8796508 DOI: 10.1186/s12915-021-01212-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/14/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Phylogenomic studies over the past two decades have consolidated the major branches of the arthropod tree of life. However, especially within the Chelicerata (spiders, scorpions, and kin), interrelationships of the constituent taxa remain controversial. While sea spiders (Pycnogonida) are firmly established as sister group of all other extant representatives (Euchelicerata), euchelicerate phylogeny itself is still contested. One key issue concerns the marine horseshoe crabs (Xiphosura), which recent studies recover either as sister group of terrestrial Arachnida or nested within the latter, with significant impact on postulated terrestrialization scenarios and long-standing paradigms of ancestral chelicerate traits. In potential support of a nested placement, previous neuroanatomical studies highlighted similarities in the visual pathway of xiphosurans and some arachnopulmonates (scorpions, whip scorpions, whip spiders). However, contradictory descriptions of the pycnogonid visual system hamper outgroup comparison and thus character polarization. RESULTS To advance the understanding of the pycnogonid brain and its sense organs with the aim of elucidating chelicerate visual system evolution, a wide range of families were studied using a combination of micro-computed X-ray tomography, histology, dye tracing, and immunolabeling of tubulin, the neuropil marker synapsin, and several neuroactive substances (including histamine, serotonin, tyrosine hydroxylase, and orcokinin). Contrary to previous descriptions, the visual system displays a serial layout with only one first-order visual neuropil connected to a bilayered arcuate body by catecholaminergic interneurons. Fluorescent dye tracing reveals a previously reported second visual neuropil as the target of axons from the lateral sense organ instead of the eyes. CONCLUSIONS Ground pattern reconstruction reveals remarkable neuroanatomical stasis in the pycnogonid visual system since the Ordovician or even earlier. Its conserved layout exhibits similarities to the median eye pathway in euchelicerates, especially in xiphosurans, with which pycnogonids share two median eye pairs that differentiate consecutively during development and target one visual neuropil upstream of the arcuate body. Given multiple losses of median and/or lateral eyes in chelicerates, and the tightly linked reduction of visual processing centers, interconnections between median and lateral visual neuropils in xiphosurans and arachnopulmonates are critically discussed, representing a plausible ancestral condition of taxa that have retained both eye types.
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Affiliation(s)
- Georg Brenneis
- Universität Greifswald, Zoologisches Institut und Museum, AG Cytologie und Evolutionsbiologie, Soldmannstraße 23, 17489, Greifswald, Germany.
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Martin C, Jahn H, Klein M, Hammel JU, Stevenson PA, Homberg U, Mayer G. The velvet worm brain unveils homologies and evolutionary novelties across panarthropods. BMC Biol 2022; 20:26. [PMID: 35073910 PMCID: PMC9136957 DOI: 10.1186/s12915-021-01196-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 11/16/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The evolution of the brain and its major neuropils in Panarthropoda (comprising Arthropoda, Tardigrada and Onychophora) remains enigmatic. As one of the closest relatives of arthropods, onychophorans are regarded as indispensable for a broad understanding of the evolution of panarthropod organ systems, including the brain, whose anatomical and functional organisation is often used to gain insights into evolutionary relations. However, while numerous recent studies have clarified the organisation of many arthropod nervous systems, a detailed investigation of the onychophoran brain with current state-of-the-art approaches is lacking, and further inconsistencies in nomenclature and interpretation hamper its understanding. To clarify the origins and homology of cerebral structures across panarthropods, we analysed the brain architecture in the onychophoran Euperipatoides rowelli by combining X-ray micro-computed tomography, histology, immunohistochemistry, confocal microscopy, and three-dimensional reconstruction. RESULTS Here, we use this detailed information to generate a consistent glossary for neuroanatomical studies of Onychophora. In addition, we report novel cerebral structures, provide novel details on previously known brain areas, and characterise further structures and neuropils in order to improve the reproducibility of neuroanatomical observations. Our findings support homology of mushroom bodies and central bodies in onychophorans and arthropods. Their antennal nerve cords and olfactory lobes most likely evolved independently. In contrast to previous reports, we found no evidence for second-order visual neuropils, or a frontal ganglion in the velvet worm brain. CONCLUSION We imaged the velvet worm nervous system at an unprecedented level of detail and compiled a comprehensive glossary of known and previously uncharacterised neuroanatomical structures to provide an in-depth characterisation of the onychophoran brain architecture. We expect that our data will improve the reproducibility and comparability of future neuroanatomical studies.
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Affiliation(s)
- Christine Martin
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany.
| | - Henry Jahn
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany
| | - Mercedes Klein
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany
| | - Jörg U Hammel
- Institute of Materials Physics, Helmholtz-Zentrum hereon, 21502, Geesthacht, Germany
| | - Paul A Stevenson
- Physiology of Animals and Behaviour, Institute of Biology, University of Leipzig, 04103, Leipzig, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, 35043, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, 35032, Marburg, Germany
| | - Georg Mayer
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany.
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Anatomy of the Nervous System in Chelifer cancroides (Arachnida: Pseudoscorpiones) with a Distinct Sensory Pathway Associated with the Pedipalps. INSECTS 2021; 13:insects13010025. [PMID: 35055868 PMCID: PMC8780800 DOI: 10.3390/insects13010025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary Most arthropods (uniting animals such as the chelicerates, e.g., spiders and their kin, as well as millipedes, centipedes, crustaceans, and insects) have distinct sensory appendages at the second head segment, the so-called antennae. The Arachnida (e.g., spiders and scorpions) do not possess antennae, but have evolved highly specialized sensory organs on different body regions. However, very limited information is available concerning pseudoscorpions (false scorpions). These animals do not seem to possess such specialized structures, but show dominant, multifunctional appendages prior to the first walking leg, called pedipalps. Here, we investigate the neuronal pathway of these structures as well as general aspects of the nervous system. We describe new details of typical arthropod brain compartments, such as the arcuate body and a comparatively small mushroom body. Neurons associated with the pedipalps terminate in two regions in the central nervous system of characteristic arrangement: a glomerular and a layered center, which we interpret as a chemo- and a mechanosensory center, respectively. The centers, which fulfill the same function in other animals, show a similar arrangement. These similarities in the sensory systems of different evolutionary origin have to be interpreted as functional prerequisites. Identifying these similarities helps to understand the general functionality of sensory systems, not only within arthropods. Abstract Many arachnid taxa have evolved unique, highly specialized sensory structures such as antenniform legs in Amblypygi (whip spiders), for instance, or mesosomal pectines in scorpions. Knowledge of the neuroanatomy as well as functional aspects of these sensory organs is rather scarce, especially in comparison to other arthropod clades. In pseudoscorpions, no special sensory structures have been discovered so far. Nevertheless, these animals possess dominant, multifunctional pedipalps, which are good candidates for being the primary sensory appendages. However, only little is known about the anatomy of the nervous system and the projection pattern of pedipalpal afferents in this taxon. By using immunofluorescent labeling of neuronal structures as well as lipophilic dye labeling of pedipalpal pathways, we identified the arcuate body, as well as a comparatively small mushroom body, the latter showing some similarities to that of Solifugae (sun spiders and camel spiders). Furthermore, afferents from the pedipalps terminate in a glomerular and a layered neuropil. Due to the innervation pattern and structural appearance, we conclude that these neuropils are the first integration centers of the chemosensory and mechanosensory afferents. Within Arthropoda, but also other invertebrates or even vertebrates, sensory structures show rather similar neuronal arrangement. Thus, these similarities in the sensory systems of different evolutionary origin have to be interpreted as functional prerequisites of the respective modality.
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Sinakevitch I, Long SM, Gronenberg W. The central nervous system of whip spiders (Amblypygi): Large mushroom bodies receive olfactory and visual input. J Comp Neurol 2021; 529:1642-1658. [PMID: 32978799 DOI: 10.1002/cne.25045] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 12/30/2022]
Abstract
Whip spiders (Amblypygi) are known for their nocturnal navigational abilities, which rely on chemosensory and tactile cues and, to a lesser degree, on vision. Unlike true spiders, the first pair of legs in whip spiders is modified into extraordinarily long sensory organs (antenniform legs) covered with thousands of mechanosensory, olfactory, and gustatory sensilla. Olfactory neurons send their axons through the leg nerve into the corresponding neuromere of the central nervous system, where they terminate on a particularly large number (about 460) of primary olfactory glomeruli, suggesting an advanced sense of smell. From the primary glomeruli, olfactory projection neurons ascend to the brain and terminate in the mushroom body calyx on a set of secondary olfactory glomeruli, a feature that is not known from olfactory pathways of other animals. Another part of the calyx receives visual input from the secondary visual neuropil (the medulla). This calyx region is composed of much smaller glomeruli ("microglomeruli"). The bimodal input and the exceptional size of their mushroom bodies may support the navigational capabilities of whip spiders. In addition to input to the mushroom body, we describe other general anatomical features of the whip spiders' central nervous system.
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Affiliation(s)
- Irina Sinakevitch
- Department of Neuroscience, University of Arizona, Tucson, Arizona, USA
| | - Skye M Long
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, USA
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Lehmann T, Melzer RR. Outsourcing a visual neuropil - The central visual system of the median eyes of Galeodes granti Pocock, 1903 (Arachnida: Solifugae). ARTHROPOD STRUCTURE & DEVELOPMENT 2021; 60:101024. [PMID: 33383276 DOI: 10.1016/j.asd.2020.101024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Only a few studies have examined the central visual system of Solifugae until now. To get new insights suitable for phylogenetic analysis we studied the R-cell (or retinula cell) projections and visual neuropils of Galeodes granti using various methods. G. granti possesses large median eyes and rudimentary lateral eyes. In this study, only the R-cells and neuropils of the median eyes were successfully stained. The R-cells terminate in two distinct visual neuropils. The first neuropil is located externally to the protocerebrum directly below the retina, the second neuropil lies in the cell body rind of the protocerebrum, and immediately adjacent is the arcuate body. This layout of the median eye visual system differs from Arachnopulmonata (Scorpiones + Tetrapulmonata). However, there are several similarities with Opiliones. In both, (1) the R-cells are connected to a first and second visual neuropil and not to any other region of the brain, (2) the first neuropil is not embedded in the cell body rind of the protocerebrum, it is rather external to the protocerebrum, (3) the second visual neuropil is embedded in the cell body rind, and (4) the second neuropil abuts the arcuate body. These findings may provide important new characters for the discussion on arachnid phylogeny.
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Affiliation(s)
- Tobias Lehmann
- Bavarian State Collection of Zoology - SNSB, Münchhausenstraße 21, 81247, Munich, Germany.
| | - Roland R Melzer
- Bavarian State Collection of Zoology - SNSB, Münchhausenstraße 21, 81247, Munich, Germany; Ludwig-Maximilians-Universität München, Department Biologie II, Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany; GeoBioCenter(LMU), Richard -Wagner-Str. 10, 80333 Munich, Germany
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Abstract
For centuries, the eye has fascinated scientists and philosophers alike, and as a result the visual system has always been at the forefront of integrating cutting-edge technology in research. We are again at a turning point at which technical advances have expanded the range of organisms we can study developmentally and deepened what we can learn. In this new era, we are finally able to understand eye development in animals across the phylogenetic tree. In this Review, we highlight six areas in comparative visual system development that address questions that are important for understanding the developmental basis of evolutionary change. We focus on the opportunities now available to biologists to study the developmental genetics, cell biology and morphogenesis that underlie the incredible variation of visual organs found across the Metazoa. Although decades of important work focused on gene expression has suggested homologies and potential evolutionary relationships between the eyes of diverse animals, it is time for developmental biologists to move away from this reductive approach. We now have the opportunity to celebrate the differences and diversity in visual organs found across animal development, and to learn what it can teach us about the fundamental principles of biological systems and how they are built.
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Affiliation(s)
- Kristen M Koenig
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA
| | - Jeffrey M Gross
- Departments of Ophthalmology and Developmental Biology, Louis J. Fox Center for Vision Restoration, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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Homing in the arachnid taxa Araneae and Amblypygi. Anim Cogn 2020; 23:1189-1204. [PMID: 32894371 DOI: 10.1007/s10071-020-01424-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 08/19/2020] [Accepted: 08/28/2020] [Indexed: 01/06/2023]
Abstract
Adequate homing is essential for the survival of any animal when it leaves its home to find prey or a mate. There are several strategies by which homing can be carried out: (a) retrace the outbound path; (b) use a 'cognitive map'; or (c) use path integration (PI). Here, I review the state of the art of research on spiders (Araneae) and whip spiders (Amblypygi) homing behaviour. The main strategy described in the literature as being used by these arachnids is PI. Behavioural and neural substrates of PI are described in a small group of spider families (Agelenidae, Lycosidae, Gnaphosidae, Ctenidae and Theraphosidae) and a whip spider family (Phrynidae). In spiders, the cues used to detect the position of the animal relative to its home are the position of the sun, polarized light patterns, web elasticity and landmarks. In whip spiders, the cues used are olfactory, tactile and, with a more minor role, visual. The use of a magnetic field in whip spiders has been rejected both with field and laboratory studies. Concerning the distance walked in PI, the possibility of using optic flow and idiothetic information in spiders is considered. The studies about outbound and inbound paths in whip spiders seem to suggest they do not follow the PI rules. As a conclusion, these arachnids' navigation relies on multimodal cues. We have detailed knowledge about the sensory origin (visual, olfactory, mechanosensory receptors) of neural information, but we are far from knowing the central neural structures where sensory information is integrated.
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Long SM. Variations on a theme: Morphological variation in the secondary eye visual pathway across the order of Araneae. J Comp Neurol 2020; 529:259-280. [DOI: 10.1002/cne.24945] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 01/10/2023]
Affiliation(s)
- Skye M. Long
- Biology Department University Massachusetts Amherst Amherst Massachusetts USA
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Steinhoff POM, Uhl G, Harzsch S, Sombke A. Visual pathways in the brain of the jumping spider Marpissa muscosa. J Comp Neurol 2020; 528:1883-1902. [PMID: 31960432 DOI: 10.1002/cne.24861] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 01/29/2023]
Abstract
Some animals have evolved task differentiation among their eyes. A particular example is spiders, where most species have eight eyes, of which two (the principal eyes) are used for object discrimination, whereas the other three pairs (secondary eyes) detect movement. In the ctenid spider Cupiennius salei, these two eye types correspond to two visual pathways in the brain. Each eye is associated with its own first- and second-order visual neuropil. The second-order neuropils of the principal eyes are connected to the arcuate body, whereas the second-order neuropils of the secondary eyes are linked to the mushroom body. We explored the principal- and secondary eye visual pathways of the jumping spider Marpissa muscosa, in which size and visual fields of the two eye types are considerably different. We found that the connectivity of the principal eye pathway is the same as in C. salei, while there are differences in the secondary eye pathways. In M. muscosa, all secondary eyes are connected to their own first-order visual neuropils. The first-order visual neuropils of the anterior lateral and posterior lateral eyes are connected with a second-order visual neuropil each and an additional shared one (L2). In the posterior median eyes, the axons of their first-order visual neuropils project directly to the arcuate body, suggesting that the posterior median eyes do not detect movement. The L2 might function as an upstream integration center enabling faster movement decisions.
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Affiliation(s)
- Philip O M Steinhoff
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
| | - Gabriele Uhl
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
| | - Steffen Harzsch
- Cytology and Evolutionary Biology, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
| | - Andy Sombke
- Department of Integrative Zoology, University of Vienna, Vienna, Austria
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Sombke A, Klann AE, Lipke E, Wolf H. Primary processing neuropils associated with the malleoli of camel spiders (Arachnida, Solifugae): a re-evaluation of axonal pathways. ZOOLOGICAL LETTERS 2019; 5:26. [PMID: 31388441 PMCID: PMC6679463 DOI: 10.1186/s40851-019-0137-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/19/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Arachnids possess highly specialized and unorthodox sense organs, such as the unique pectines of Scorpiones and the malleoli of Solifugae. While the external morphology, numbers, and shapes of sensory organs are widely used in taxonomic studies, little is known about the internal anatomy of these organs and their associated processing neuropils in the central nervous system. Camel spiders (Solifugae) possess pedipalps and first walking legs heavily endowed with sensory structures, as well as conspicuous malleoli located ventrally on the proximal fourth walking legs. Malleoli are fan-shaped organs that contain tens of thousands of presumptive chemoreceptor neurons, but mechanoreceptive structures are absent. RESULTS Here, we examine the organization of the synganglion based on microCT analysis, 3D reconstruction of serial paraffin sections, and backfill preparations to trace the malleolar pathway. The projection area of malleolar afferents is intriguingly located in the most anterior ventral nerve cord, located in between the pedipalpal neuromere hemispheres. However, malleolar axon bundles are separated by a thin soma layer that points to an anteriad projection of the fourth walking leg neuromere. A conspicuous projection neuron tract that may receive additional input from pedipalpal sensory organs connects the malleolar neuropil with the mushroom bodies in the protocerebrum. CONCLUSION Arthropod chemosensory appendages or organs and primary processing neuropils are typically located in the same segment, which also holds true in Solifugae, although the malleolar neuropil is partially shifted towards the pedipalpal neuromere. A comparison of the malleoli in Solifugae and the pectines in Scorpiones, and of their primary processing neuropils, reveals certain similarities, while striking differences are also evident. Similarities include the ventral arrangement of peg-shaped sensory structures on the respective segmental appendage, exposing dense arrays of chemoreceptive sensilla, and projections to a primary processing neuropil with glomerular subdivision. Differences are, e.g., the lack of mechanoreceptive afferents and an associated processing neuropil.
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Affiliation(s)
- Andy Sombke
- University of Vienna, Department of Integrative Zoology, Althanstrasse 14, 1090 Vienna, Austria
| | - Anja E. Klann
- Department of Forensic Molecular Genetics, University Medicine Greifswald, Institute of Legal Medicine, 17489 Greifswald, Germany
| | - Elisabeth Lipke
- German Air Force Center of Aerospace Medicine, 82256 Fürstenfeldbruck, Germany
| | - Harald Wolf
- Wallenberg Research Centre, Stellenbosch Institute for Advanced Study, 10 Marais Street, Stellenbosch, 7600 South Africa
- Present address: Institut für Neurobiologie, Universität Ulm, 89069 Ulm, Germany
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Lehmann T, Melzer RR. The visual system of Thelyphonida (whip scorpions): Support for Arachnopulmonata. ARTHROPOD STRUCTURE & DEVELOPMENT 2019; 51:23-31. [PMID: 31176004 DOI: 10.1016/j.asd.2019.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/03/2019] [Accepted: 06/04/2019] [Indexed: 06/09/2023]
Abstract
Only a few studies have examined the central visual system of Thelyphonida (whip scorpions) until now. To obtain new insights suitable for phylogenetic analysis we studied the axonal trajectories and neuropil architecture of the central visual systems of two whip scorpion species (Mastigoproctus giganteus and Typopeltis dalyi) with different neuroanatomical techniques (Cobalt fills, Wigglesworth stains, and μCT). The central visual system of whip scorpion comprises one pair of median eyes and one pair of lateral eye triplets. The R-cells (or retinula cells) of both eye types each terminate in a first and a second visual neuropil. Furthermore, a few R-cell fibres from the median eyes leave the second median eye visual neuropil and terminate in the second and the first lateral eye neuropil. This means R-cell terminals from the lateral eyes and the median eyes overlap here. Additionally, the arcuate body and mushroom bodies are described. A detailed comparison of our findings with previously studied chelicerate central visual systems seems to support a monophyly of Arachnopulmonata, i.e. a clade comprising Tetrapulmonata (Thelyphonida, Schizomida, Amblypygi, and Araneae) and Scorpions. Furthermore, the architecture of the central visual systems hints at a close evolutionary relationship of Arachnopulmonata and Xiphosura.
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Affiliation(s)
- Tobias Lehmann
- Bavarian State Collection of Zoology - SNSB, Münchhausenstraße 21, 81247, Munich, Germany.
| | - Roland R Melzer
- Bavarian State Collection of Zoology - SNSB, Münchhausenstraße 21, 81247, Munich, Germany; Ludwig-Maximilians-Universität München, Department Biologie II, Großhaderner Straße 2, 82152, Planegg-Martinsried, Germany; GeoBioCenter(LMU), Richard -Wagner-Str. 10, 80333, Munich, Germany
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Nagata T, Arikawa K, Kinoshita M. Photoreceptor projection from a four‐tiered retina to four distinct regions of the first optic ganglion in a jumping spider. J Comp Neurol 2019; 527:1348-1361. [DOI: 10.1002/cne.24584] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 11/12/2018] [Accepted: 11/16/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Takashi Nagata
- Laboratory of NeuroethologySchool of Advanced Sciences, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village Hayama Japan
| | - Kentaro Arikawa
- Laboratory of NeuroethologySchool of Advanced Sciences, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village Hayama Japan
| | - Michiyo Kinoshita
- Laboratory of NeuroethologySchool of Advanced Sciences, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village Hayama Japan
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Lehmann T, Melzer RR. Also looking like Limulus? - retinula axons and visual neuropils of Amblypygi (whip spiders). Front Zool 2018; 15:52. [PMID: 30574172 PMCID: PMC6299927 DOI: 10.1186/s12983-018-0293-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/05/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Only a few studies have examined the visual systems of Amblypygi (whip spiders) until now. To get new insights suitable for phylogenetic analysis we studied the axonal trajectories and neuropil architecture of the visual systems of several whip spider species (Heterophrynus elaphus, Damon medius, Phrynus pseudoparvulus, and P. marginemaculatus) with different neuroanatomical techniques. The R-cell axon terminals were identified with Cobalt fills. To describe the morphology of the visual neuropils and of the protocerebrum generally we used Wigglesworth stains and μCT. RESULTS The visual system of whip spiders comprises one pair of median and three pairs of lateral eyes. The R-cells of both eye types terminate each in a first and a second visual neuropil. Furthermore, a few R-cell fibres from the median eyes leave the second median eye visual neuropil and terminate in the second lateral eye neuropil. This means R-cell terminals from the lateral eyes and the median eyes overlap. Additionally, the arcuate body and the mushroom bodies are described. CONCLUSIONS A detailed comparison of our findings with previously studied chelicerate visual systems (i.e., Xiphosura, Scorpiones, Pseudoscorpiones, Opiliones, and Araneae) seem to support the idea of close evolutionary relationships between Xiphosura, Scorpiones, and Amblypygi.
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Affiliation(s)
- Tobias Lehmann
- Bavarian State Collection of Zoology – SNSB, Münchhausenstraße 21, 81247 Munich, Germany
- Ludwig-Maximilians-Universität München, Department Biologie II, Großhaderner Straße 2, 82152, Planegg-Martinsried, Germany
| | - Roland R. Melzer
- Bavarian State Collection of Zoology – SNSB, Münchhausenstraße 21, 81247 Munich, Germany
- Ludwig-Maximilians-Universität München, Department Biologie II, Großhaderner Straße 2, 82152, Planegg-Martinsried, Germany
- GeoBioCenter LMU, Richard -Wagner-Str. 10, 80333 Munich, Germany
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Fine Structure of the Neuroganglia in the Central Nervous System of the Harvestman Leiobunum japonicum (Arachnida: Opiliones). Appl Microsc 2018. [DOI: 10.9729/am.2018.48.1.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Lehmann T, Melzer RR. A tiny visual system — retinula axons and visual neuropils of Neobisium carcinoides (Hermann, 1804) (Chelicerata, Arachnida, Pseudoscorpiones). ZOOL ANZ 2018. [DOI: 10.1016/j.jcz.2017.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The discovery of fossilized brains and ventral nerve cords in lower and mid-Cambrian arthropods has led to crucial insights about the evolution of their central nervous system, the segmental identity of head appendages and the early evolution of eyes and their underlying visual systems. Fundamental ground patterns of lower Cambrian arthropod brains and nervous systems correspond to the ground patterns of brains and nervous systems belonging to three of four major extant panarthropod lineages. These findings demonstrate the evolutionary stability of early neural arrangements over an immense time span. Here, we put these fossil discoveries in the context of evidence from cladistics, as well as developmental and comparative neuroanatomy, which together suggest that despite many evolved modifications of neuropil centers within arthropod brains and ganglia, highly conserved arrangements have been retained. Recent phylogenies of the arthropods, based on fossil and molecular evidence, and estimates of divergence dates, suggest that neural ground patterns characterizing onychophorans, chelicerates and mandibulates are likely to have diverged between the terminal Ediacaran and earliest Cambrian, heralding the exuberant diversification of body forms that account for the Cambrian Explosion.
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Affiliation(s)
- Nicholas J Strausfeld
- Department of Neuroscience and Center for Insect Science, University of Arizona, Tucson, AZ 85721, USA.
| | - Xiaoya Ma
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK; Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming 650091, People's Republic of China
| | - Gregory D Edgecombe
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK.
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Napiórkowska T, Kobak J. The allometry of the central nervous system during the postembryonic development of the spider Eratigena atrica. ARTHROPOD STRUCTURE & DEVELOPMENT 2017; 46:805-814. [PMID: 28864302 DOI: 10.1016/j.asd.2017.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/22/2017] [Accepted: 08/26/2017] [Indexed: 06/07/2023]
Abstract
During ontogenesis, the size of a spider body, tissues and organs increases dramatically. The aim of the study was to estimate changes in the central nervous system of postembryonic stages of Eratigena atrica and compare them with the literature data on species differing in behavioural traits. Allometric analysis involved evaluation of histological slides embedded in paraffin and stained with hematoxylin and eosin. The reduced major axis regression (RMA) was applied to find allometric relationships between the volumes of the particular parts of the body. All the measured parts of the central nervous system (CNS) were negatively allometrically related to the volume of the prosoma, showing that the increment of the CNS was lower than that of the entire body. The growth of the brain was negatively allometrically related to the growth of the CNS but the increment of the subesophageal ganglion was greater than that of the CNS, exhibiting a positive allometry. Within both these structures, the increase in neuropil volume was greater than the growth of the cortex (cell body rind). Thus, in postembryonic development, the share of the subesophageal ganglion and neuropil in the total volume of the CNS increased, whereas that of the brain and cortex decreased. The mode of the CNS development in E. atrica is similar to that observed in other arthropods, including Argiope aurantia, a spider of different ecology and behaviour.
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Affiliation(s)
- Teresa Napiórkowska
- Department of Invertebrate Zoology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, 87-100 Toruń, Lwowska 1, Poland.
| | - Jarosław Kobak
- Department of Invertebrate Zoology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, 87-100 Toruń, Lwowska 1, Poland.
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Steinhoff POM, Liedtke J, Sombke A, Schneider JM, Uhl G. Early environmental conditions affect the volume of higher-order brain centers in a jumping spider. J Zool (1987) 2017. [DOI: 10.1111/jzo.12512] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- P. O. M. Steinhoff
- General and Systematic Zoology; Zoological Institute and Museum; University of Greifswald; Greifswald Germany
| | - J. Liedtke
- Biocenter Grindel; Zoological Institute; University of Hamburg; Hamburg Germany
| | - A. Sombke
- Cytology and Evolutionary Biology; Zoological Institute and Museum; University of Greifswald; Greifswald Germany
| | - J. M. Schneider
- Biocenter Grindel; Zoological Institute; University of Hamburg; Hamburg Germany
| | - G. Uhl
- General and Systematic Zoology; Zoological Institute and Museum; University of Greifswald; Greifswald Germany
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Ortega-Escobar J, Ruiz MA. Role of the different eyes in the visual odometry in the wolf spider Lycosa tarantula (Araneae, Lycosidae). ACTA ACUST UNITED AC 2017; 220:259-265. [PMID: 28100804 DOI: 10.1242/jeb.145763] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/22/2016] [Indexed: 11/20/2022]
Abstract
The wolf spider Lycosa tarantula returns home by means of path integration. Previous studies demonstrated: (i) that the angular component of the outbound run is measured using a polarized-light compass associated with the anterior median eyes; (ii) changes in direction of the substratum are detected by the anterior lateral eyes (ALEs); and (iii) in relation to the linear component of the outbound run, an increase of optic flow, in either the lateral or ventral fields of view, caused spiders to search for the burrow at a point nearer to the goal. However, the role of the secondary eyes [ALEs, posterior lateral eyes (PLEs) and posterior median eyes (PMEs)] in the perception of this optic flow and the importance of them for gauging the distance walked is still unknown. In this study, lateral or ventral gratings of wavelength λ=1 cm were used, with two groups of spiders in each setup: (1) PLEs+PMEs covered and (2) ALEs covered. The largest reduction in the distance walked to return to the burrow was observed with the ventral grating/ALEs covered. These results show the importance of the previously neglected ALEs for the visual behavior of these spiders. The possibility of gathering information for locomotion from the three pairs of secondary eyes in the mushroom bodies is discussed.
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Affiliation(s)
| | - Miguel A Ruiz
- School of Psychology, University Autónoma of Madrid, Madrid 28049, Spain
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Morehouse NI, Buschbeck EK, Zurek DB, Steck M, Porter ML. Molecular Evolution of Spider Vision: New Opportunities, Familiar Players. THE BIOLOGICAL BULLETIN 2017; 233:21-38. [PMID: 29182503 DOI: 10.1086/693977] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Spiders are among the world's most species-rich animal lineages, and their visual systems are likewise highly diverse. These modular visual systems, composed of four pairs of image-forming "camera" eyes, have taken on a huge variety of forms, exhibiting variation in eye size, eye placement, image resolution, and field of view, as well as sensitivity to color, polarization, light levels, and motion cues. However, despite this conspicuous diversity, our understanding of the genetic underpinnings of these visual systems remains shallow. Here, we review the current literature, analyze publicly available transcriptomic data, and discuss hypotheses about the origins and development of spider eyes. Our efforts highlight that there are many new things to discover from spider eyes, and yet these opportunities are set against a backdrop of deep homology with other arthropod lineages. For example, many (but not all) of the genes that appear important for early eye development in spiders are familiar players known from the developmental networks of other model systems (e.g., Drosophila). Similarly, our analyses of opsins and related phototransduction genes suggest that spider photoreceptors employ many of the same genes and molecular mechanisms known from other arthropods, with a hypothesized ancestral spider set of four visual and four nonvisual opsins. This deep homology provides a number of useful footholds into new work on spider vision and the molecular basis of its extant variety. We therefore discuss what some of these first steps might be in the hopes of convincing others to join us in studying the vision of these fascinating creatures.
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Key Words
- AL, anterior lateral
- AM, anterior median
- BLAST, Basic Local Alignment Search Tool
- CNS, central nervous system
- KAAS, KEGG Automatic Annotation Server
- KEGG, Kyoto Encyclopedia of Genes and Genomes
- LWS, long wavelength sensitive
- MAFFT, Multiple Alignment using Fast Fourier Transform
- MWS, middle wavelength sensitive
- PL, posterior lateral
- PM, posterior median
- RAxML, Randomized Axelerated Maximum Likelihood
- UVS, ultraviolet sensitive
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Fabian-Fine R, Anderson CM, Roush MA, Johnson JAG, Liu H, French AS, Torkkeli PH. The distribution of cholinergic neurons and their co-localization with FMRFamide, in central and peripheral neurons of the spider Cupiennius salei. Cell Tissue Res 2017; 370:71-88. [PMID: 28687927 DOI: 10.1007/s00441-017-2652-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 05/23/2017] [Indexed: 12/21/2022]
Abstract
The spider Cupiennius salei is a well-established model for investigating information processing in arthropod sensory systems. Immunohistochemistry has shown that several neurotransmitters exist in the C. salei nervous system, including GABA, glutamate, histamine, octopamine and FMRFamide, while electrophysiology has found functional roles for some of these transmitters. There is also evidence that acetylcholine (ACh) is present in some C. salei neurons but information about the distribution of cholinergic neurons in spider nervous systems is limited. Here, we identify C. salei genes that encode enzymes essential for cholinergic transmission: choline ACh transferase (ChAT) and vesicular ACh transporter (VAChT). We used in-situ hybridization with an mRNA probe for C. salei ChAT gene to locate somata of cholinergic neurons in the central nervous system and immunohistochemistry with antisera against ChAT and VAChT to locate these proteins in cholinergic neurons. All three markers labeled similar, mostly small neurons, plus a few mid-sized neurons, in most ganglia. In the subesophageal ganglia, labeled neurons are putative efferent, motor or interneurons but the largest motor and interneurons were unlabeled. Groups of anti-ChAT labeled small neurons also connect the optic neuropils in the spider protocerebrum. Differences in individual cell labeling intensities were common, suggesting a range of ACh expression levels. Double-labeling found a subpopulation of anti-VAChT-labeled central and mechanosensory neurons that were also immunoreactive to antiserum against FMRFamide-like peptides. Our findings suggest that ACh is an important neurotransmitter in the C. salei central and peripheral nervous systems.
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Affiliation(s)
- Ruth Fabian-Fine
- Department of Biology, Saint Michael's College, One Winooski Park, Box 283, Colchester, VT, 05439, USA.
| | - Carly M Anderson
- Department of Biology, Saint Michael's College, One Winooski Park, Box 283, Colchester, VT, 05439, USA
| | - Molly A Roush
- Department of Biology, Saint Michael's College, One Winooski Park, Box 283, Colchester, VT, 05439, USA
| | - Jessica A G Johnson
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Hongxia Liu
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Andrew S French
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Päivi H Torkkeli
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
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Sensory system plasticity in a visually specialized, nocturnal spider. Sci Rep 2017; 7:46627. [PMID: 28429798 PMCID: PMC5399460 DOI: 10.1038/srep46627] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 03/22/2017] [Indexed: 01/01/2023] Open
Abstract
The interplay between an animal’s environmental niche and its behavior can influence the evolutionary form and function of its sensory systems. While intraspecific variation in sensory systems has been documented across distant taxa, fewer studies have investigated how changes in behavior might relate to plasticity in sensory systems across developmental time. To investigate the relationships among behavior, peripheral sensory structures, and central processing regions in the brain, we take advantage of a dramatic within-species shift of behavior in a nocturnal, net-casting spider (Deinopis spinosa), where males cease visually-mediated foraging upon maturation. We compared eye diameters and brain region volumes across sex and life stage, the latter through micro-computed X-ray tomography. We show that mature males possess altered peripheral visual morphology when compared to their juvenile counterparts, as well as juvenile and mature females. Matching peripheral sensory structure modifications, we uncovered differences in relative investment in both lower-order and higher-order processing regions in the brain responsible for visual processing. Our study provides evidence for sensory system plasticity when individuals dramatically change behavior across life stages, uncovering new avenues of inquiry focusing on altered reliance of specific sensory information when entering a new behavioral niche.
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Steinhoff POM, Sombke A, Liedtke J, Schneider JM, Harzsch S, Uhl G. The synganglion of the jumping spider Marpissa muscosa (Arachnida: Salticidae): Insights from histology, immunohistochemistry and microCT analysis. ARTHROPOD STRUCTURE & DEVELOPMENT 2017; 46:156-170. [PMID: 27845202 DOI: 10.1016/j.asd.2016.11.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/30/2016] [Accepted: 11/04/2016] [Indexed: 06/06/2023]
Abstract
Jumping spiders are known for their extraordinary cognitive abilities. The underlying nervous system structures, however, are largely unknown. Here, we explore and describe the anatomy of the brain in the jumping spider Marpissa muscosa (Clerck, 1757) by means of paraffin histology, X-ray microCT analysis and immunohistochemistry as well as three-dimensional reconstruction. In the prosoma, the CNS is a clearly demarcated mass that surrounds the esophagus. The anteriormost neuromere, the protocerebrum, comprises nine bilaterally paired neuropils, including the mushroom bodies and one unpaired midline neuropil, the arcuate body. Further ventrally, the synganglion comprises the cheliceral (deutocerebrum) and pedipalpal neuropils (tritocerebrum). Synapsin-immunoreactivity in all neuropils is generally strong, while allatostatin-immunoreactivity is mostly present in association with the arcuate body and the stomodeal bridge. The most prominent neuropils in the spider brain, the mushroom bodies and the arcuate body, were suggested to be higher integrating centers of the arthropod brain. The mushroom body in M. muscosa is connected to first and second order visual neuropils of the lateral eyes, and the arcuate body to the second order neuropils of the anterior median eyes (primary eyes) through a visual tract. The connection of both, visual neuropils and eyes and arcuate body, as well as their large size corroborates the hypothesis that these neuropils play an important role in cognition and locomotion control of jumping spiders. In addition, we show that the architecture of the brain of M. muscosa and some previously investigated salticids differs significantly from that of the wandering spider Cupiennius salei, especially with regard to structure and arrangement of visual neuropils and mushroom body. Thus, we need to explore the anatomical conformities and specificities of the brains of different spider taxa in order to understand evolutionary transformations of the arthropod brain.
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Affiliation(s)
- Philip O M Steinhoff
- Zoological Institute and Museum, General and Systematic Zoology, University of Greifswald, Anklamer Straße 20, 17489 Greifswald, Germany.
| | - Andy Sombke
- Zoological Institute and Museum, Cytology and Evolutionary Biology, University of Greifswald, Soldmannstraße 23, 17487 Greifswald, Germany.
| | - Jannis Liedtke
- Zoological Institute, Biozentrum Grindel, University of Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Jutta M Schneider
- Zoological Institute, Biozentrum Grindel, University of Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Steffen Harzsch
- Zoological Institute and Museum, Cytology and Evolutionary Biology, University of Greifswald, Soldmannstraße 23, 17487 Greifswald, Germany
| | - Gabriele Uhl
- Zoological Institute and Museum, General and Systematic Zoology, University of Greifswald, Anklamer Straße 20, 17489 Greifswald, Germany.
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Petralia RS, Wang YX, Mattson MP, Yao PJ. The Diversity of Spine Synapses in Animals. Neuromolecular Med 2016; 18:497-539. [PMID: 27230661 PMCID: PMC5158183 DOI: 10.1007/s12017-016-8405-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/11/2016] [Indexed: 12/23/2022]
Abstract
Here we examine the structure of the various types of spine synapses throughout the animal kingdom. Based on available evidence, we suggest that there are two major categories of spine synapses: invaginating and non-invaginating, with distributions that vary among different groups of animals. In the simplest living animals with definitive nerve cells and synapses, the cnidarians and ctenophores, most chemical synapses do not form spine synapses. But some cnidarians have invaginating spine synapses, especially in photoreceptor terminals of motile cnidarians with highly complex visual organs, and also in some mainly sessile cnidarians with rapid prey capture reflexes. This association of invaginating spine synapses with complex sensory inputs is retained in the evolution of higher animals in photoreceptor terminals and some mechanoreceptor synapses. In contrast to invaginating spine synapse, non-invaginating spine synapses have been described only in animals with bilateral symmetry, heads and brains, associated with greater complexity in neural connections. This is apparent already in the simplest bilaterians, the flatworms, which can have well-developed non-invaginating spine synapses in some cases. Non-invaginating spine synapses diversify in higher animal groups. We also discuss the functional advantages of having synapses on spines and more specifically, on invaginating spines. And finally we discuss pathologies associated with spine synapses, concentrating on those systems and diseases where invaginating spine synapses are involved.
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Affiliation(s)
- Ronald S Petralia
- Advanced Imaging Core, NIDCD/NIH, 35A Center Drive, Room 1E614, Bethesda, MD, 20892-3729, USA.
| | - Ya-Xian Wang
- Advanced Imaging Core, NIDCD/NIH, 35A Center Drive, Room 1E614, Bethesda, MD, 20892-3729, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, 21224, USA
| | - Pamela J Yao
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, 21224, USA
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Lehmann T, Lodde-Bensch E, Melzer RR, Metz M. The visual system of harvestmen (Opiliones, Arachnida, Chelicerata) - a re-examination. Front Zool 2016; 13:50. [PMID: 27891163 PMCID: PMC5112708 DOI: 10.1186/s12983-016-0182-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/02/2016] [Indexed: 01/31/2023] Open
Abstract
Background The visual systems in chelicerates are poorly understood, even though they show strong variation in eye and visual neuropil architecture, thus may provide valuable insights for the understanding of chelicerate phylogeny and eye evolution. Comparable morphological characters are desperately sought for reconstructions of the phylogeny of Chelicerata, especially with respect to Arachnida. So far, reliable data exist only for Pycnogonida, Xiphosura, Scorpiones, and Araneae. The few earlier studies of the organisation of the visual system in harvestmen are contradictory concerning the number, morphology, and position of the visual neuropils. Results We undertook a descriptive and comparative analysis of the neuroanatomy of the visual system in several phalangid harvestmen species. Various traditional and modern methods were used that allow comparisons with previous results (cobalt fills, DiI/DiO labelling, osmium ethyl gallate procedure, and TEM). The R-cells (photoreceptor and arhabdomeric cells) in the eyes of Opiliones are linked to a first and a second visual neuropil. The first visual neuropil receives input from all R-cell axons, in the second only few R-cells terminate in the distal part. Hence, the second visual neuropil is subdivided in a part with direct R-cell input and a part without. The arcuate body is located in a subsequent position with direct contact to the second visual neuropil. Conclusions This re-examination comes to conclusions different from those of all previous studies. The visual system of phalangid Opiliones occupies an intermediate position between Pycnogonida, Xiphosura, and Scorpiones on the one side, and Araneae on the other side. The projection of the R-cells is similar to that in the former grouping, the general neuropil arrangement to that in the latter taxon. However, more research on the visual systems in other chelicerate orders is needed in order to draw inferences on phylogeny or eye evolution.
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Affiliation(s)
- Tobias Lehmann
- Bavarian State Collection of Zoology, SNSB, Münchhausenstraße 21, 81247 Munich, Germany ; Department Biologie II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany
| | - Eva Lodde-Bensch
- Bavarian State Collection of Zoology, SNSB, Münchhausenstraße 21, 81247 Munich, Germany
| | - Roland R Melzer
- Bavarian State Collection of Zoology, SNSB, Münchhausenstraße 21, 81247 Munich, Germany ; Department Biologie II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany ; GeoBioCenter, LMU, Richard -Wagner-Str. 10, 80333 Munich, Germany
| | - Martina Metz
- Bavarian State Collection of Zoology, SNSB, Münchhausenstraße 21, 81247 Munich, Germany
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Abstract
Large, complex brains have evolved independently in several lineages of protostomes and deuterostomes. Sensory centres in the brain increase in size and complexity in proportion to the importance of a particular sensory modality, yet often share circuit architecture because of constraints in processing sensory inputs. The selective pressures driving enlargement of higher, integrative brain centres has been more difficult to determine, and may differ across taxa. The capacity for flexible, innovative behaviours, including learning and memory and other cognitive abilities, is commonly observed in animals with large higher brain centres. Other factors, such as social grouping and interaction, appear to be important in a more limited range of taxa, while the importance of spatial learning may be a common feature in insects with large higher brain centres. Despite differences in the exact behaviours under selection, evolutionary increases in brain size tend to derive from common modifications in development and generate common architectural features, even when comparing widely divergent groups such as vertebrates and insects. These similarities may in part be influenced by the deep homology of the brains of all Bilateria, in which shared patterns of developmental gene expression give rise to positionally, and perhaps functionally, homologous domains. Other shared modifications of development appear to be the result of homoplasy, such as the repeated, independent expansion of neuroblast numbers through changes in genes regulating cell division. The common features of large brains in so many groups of animals suggest that given their common ancestry, a limited set of mechanisms exist for increasing structural and functional diversity, resulting in many instances of homoplasy in bilaterian nervous systems.
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Affiliation(s)
- Sarah M Farris
- Department of Biology, West Virginia University, 3139 Life Sciences Building, 53 Campus Drive, Morgantown, WV 26505, USA
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Wiegmann DD, Hebets EA, Gronenberg W, Graving JM, Bingman VP. Amblypygids: Model Organisms for the Study of Arthropod Navigation Mechanisms in Complex Environments? Front Behav Neurosci 2016; 10:47. [PMID: 27014008 PMCID: PMC4782058 DOI: 10.3389/fnbeh.2016.00047] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/26/2016] [Indexed: 11/26/2022] Open
Abstract
Navigation is an ideal behavioral model for the study of sensory system integration and the neural substrates associated with complex behavior. For this broader purpose, however, it may be profitable to develop new model systems that are both tractable and sufficiently complex to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement experiments under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, albeit on a smaller spatial scale, of true-navigating vertebrates. Specialized legs, called antenniform legs, which possess hundreds of olfactory and tactile sensory hairs, and vision appear to be involved. These animals also have enormous mushroom bodies, higher-order brain regions that, in insects, integrate contextual cues and may be involved in spatial memory. In amblypygids, the complexity of a nocturnal rainforest may impose navigational challenges that favor the integration of information derived from multimodal cues. Moreover, the movement of these animals is easily studied in the laboratory and putative neural integration sites of sensory information can be manipulated. Thus, amblypygids could serve as model organisms for the discovery of neural substrates associated with a unique and potentially sophisticated navigational capability. The diversity of habitats in which amblypygids are found also offers an opportunity for comparative studies of sensory integration and ecological selection pressures on navigation mechanisms.
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Affiliation(s)
- Daniel D Wiegmann
- Department of Biological Sciences, Bowling Green State UniversityBowling Green, OH, USA; J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State UniversityBowling Green, OH, USA
| | - Eileen A Hebets
- School of Biological Sciences, University of Nebraska Lincoln, NE, USA
| | | | - Jacob M Graving
- Department of Biological Sciences, Bowling Green State University Bowling Green, OH, USA
| | - Verner P Bingman
- J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State UniversityBowling Green, OH, USA; Department of Psychology, Bowling Green State UniversityBowling Green, OH, USA
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Samadi L, Schmid A, Eriksson BJ. Differential expression of retinal determination genes in the principal and secondary eyes of Cupiennius salei Keyserling (1877). EvoDevo 2015; 6:16. [PMID: 26034575 PMCID: PMC4450993 DOI: 10.1186/s13227-015-0010-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/10/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transcription factors that determine retinal development seem to be conserved in different phyla throughout the animal kingdom. In most representatives, however, only a few of the involved transcription factors have been sampled and many animal groups remain understudied. In order to fill in the gaps for the chelicerate group of arthropods, we tested the expression pattern of the candidate genes involved in the eye development in the embryo of the wandering spider Cupiennius salei. One main objective was to profile the molecular development of the eyes and to search for possible variation among eye subtype differentiation. A second aim was to form a basis for comparative studies in order to elucidate evolutionary pathways in eye development. RESULTS We screened the spider embryonic transcriptome for retina determination gene candidates and discovered that all except one of the retinal determination genes have been duplicated. Gene expression analysis shows that the two orthologs of all the genes have different expression patterns. The genes are mainly expressed in the developing optic neuropiles of the eyes (lateral furrow, mushroom body, arcuate body) in earlier stages of development (160 to 220 h after egg laying). Later in development (180 to 280 h after egg laying), there is differential expression of the genes in disparate eye vesicles; for example, Cs-otxa is expressed only in posterior-lateral eye vesicles, Cs-otxb, Cs-six1a, and Cs-six3b in all three secondary eye vesicles, Cs-pax6a only in principal eye vesicles, Cs-six1b in posterior-median, and posterior-lateral eye vesicles, and Cs-six3a in lateral and principal eye vesicles. CONCLUSIONS Principle eye development shows pax6a (ey) expression, suggesting pax6 dependence, although secondary eyes develop independently of pax6 genes and show differential expression of several retinal determination genes. Comparing this with the other arthropods suggests that pax6-dependent median eye development is a ground pattern of eye development in this group and that the ocelli of insects, the median eyes of chelicerates, and nauplius eyes can be homologised. The expression pattern of the investigated genes makes it possible to distinguish between secondary eyes and principal eyes. Differences of gene expression among the different lateral eyes indicate disparate function combined with genetic drift.
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Affiliation(s)
- Leyli Samadi
- Department of Neurobiology, Centre for Organismal Systems Biology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Axel Schmid
- Department of Neurobiology, Centre for Organismal Systems Biology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Bo Joakim Eriksson
- Department of Neurobiology, Centre for Organismal Systems Biology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
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Napiórkowska T, Napiórkowski P, Templin J. Morphological and anatomical changes related to leg anomalies in Tegenaria atrica. ZOOMORPHOLOGY 2015; 134:237-245. [PMID: 25995535 PMCID: PMC4430592 DOI: 10.1007/s00435-015-0260-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 02/12/2015] [Accepted: 02/18/2015] [Indexed: 11/30/2022]
Abstract
A range of leg anomalies was detected in embryos of the Tegenaria atrica spiders exposed to alternating temperatures of 14 and 32 °C. Multiple anomalies were observed in 13 individuals. This study is based on five individuals: two individuals affected by oligomely combined, respectively, with heterosymely and polymely, one affected by polymely with heterosymely, one by complicated polymely (accompanied by the reduction in length and malformations of the distal parts of the legs), and one individual with pure polymely. Changes in the central nervous system of these five individuals were described in detail on the basis of histological sections. The changes were mainly related to the number of neuromeres. Individuals affected by polymely had additional ganglia corresponding to the number of additional appendages, whereas the absence of a leg (oligomely) was associated with the absence of a ganglion. Histological analysis showed the fusion of ganglia in the three polymelic specimens, even though additional appendages were not fused.
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Affiliation(s)
- Teresa Napiórkowska
- Department of Invertebrate Zoology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, 87-100 Toruń, Lwowska 1, Poland
| | - Paweł Napiórkowski
- Department of Hydrobiology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, Toruń, Lwowska 1, Poland
| | - Julita Templin
- Department of Invertebrate Zoology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University, 87-100 Toruń, Lwowska 1, Poland
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Menda G, Shamble P, Nitzany E, Golden J, Hoy R. Visual Perception in the Brain of a Jumping Spider. Curr Biol 2014; 24:2580-5. [DOI: 10.1016/j.cub.2014.09.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 08/27/2014] [Accepted: 09/10/2014] [Indexed: 11/16/2022]
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Lehmann T, Melzer RR. Looking like Limulus? - Retinula axons and visual neuropils of the median and lateral eyes of scorpions. Front Zool 2013; 10:40. [PMID: 23842208 PMCID: PMC3717128 DOI: 10.1186/1742-9994-10-40] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 07/01/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950. RESULTS Scorpion median eye retinula cells are linked to a first and a second visual neuropil, while some fibres additionally connect the median eyes with the arcuate body. The lateral eye retinula cells are linked to a first and a second visual neuropil as well, with the second neuropil being partly shared by projections from both eyes. CONCLUSIONS Comparing these results to previous studies on the visual systems of scorpions and other chelicerates, we found striking similarities to the innervation pattern in Limulus polyphemus for both median and lateral eyes. This supports from a visual system point of view at least a phylogenetically basal position of Scorpiones in Arachnida, or even a close relationship to Xiphosura. In addition, we propose a ground pattern for the central projections of chelicerate median eyes.
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Affiliation(s)
- Tobias Lehmann
- SNSB – Bavarian State Collection of Zoology, Münchhausenstraße 21, Munich 81247, Germany
- Department Biology II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, Planegg-Martinsried 82152, Germany
| | - Roland R Melzer
- SNSB – Bavarian State Collection of Zoology, Münchhausenstraße 21, Munich 81247, Germany
- Department Biology II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, Planegg-Martinsried 82152, Germany
- GeoBio-Center at LMU, Richard-Wagner-Str. 10, 80333, Munich, Germany
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Microstructural Organization of the Central Nervous System in the Orb-Web Spider Araneus ventricosus (Araneae: Araneidae). Appl Microsc 2013. [DOI: 10.9729/am.2013.43.2.65] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Wolff G, Harzsch S, Hansson BS, Brown S, Strausfeld N. Neuronal organization of the hemiellipsoid body of the land hermit crab, Coenobita clypeatus: correspondence with the mushroom body ground pattern. J Comp Neurol 2012; 520:2824-46. [PMID: 22547177 DOI: 10.1002/cne.23059] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Malacostracan crustaceans and dicondylic insects possess large second-order olfactory neuropils called, respectively, hemiellipsoid bodies and mushroom bodies. Because these centers look very different in the two groups of arthropods, it has been debated whether these second-order sensory neuropils are homologous or whether they have evolved independently. Here we describe the results of neuroanatomical observations and experiments that resolve the neuronal organization of the hemiellipsoid body in the terrestrial Caribbean hermit crab, Coenobita clypeatus, and compare this organization with the mushroom body of an insect, the cockroach Periplaneta americana. Comparisons of the morphology, ultrastructure, and immunoreactivity of the hemiellipsoid body of C. clypeatus and the mushroom body of the cockroach P. americana reveal in both a layered motif provided by rectilinear arrangements of extrinsic and intrinsic neurons as well as a microglomerular organization. Furthermore, antibodies raised against DC0, the major catalytic subunit of protein kinase A, specifically label both the crustacean hemiellipsoid bodies and insect mushroom bodies. In crustaceans lacking eyestalks, where the entire brain is contained within the head, this antibody selectively labels hemiellipsoid bodies, the superior part of which approximates a mushroom body's calyx in having large numbers of microglomeruli. We propose that these multiple correspondences indicate homology of the crustacean hemiellipsoid body and insect mushroom body and discuss the implications of this with respect to the phylogenetic history of arthropods. We conclude that crustaceans, insects, and other groups of arthropods share an ancestral neuronal ground pattern that is specific to their second-order olfactory centers.
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Affiliation(s)
- Gabriella Wolff
- Department of Neuroscience, University of Arizona, Tucson, Arizona 85721, USA.
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Fenk LM, Schmid A. Flicker-induced eye movements and the behavioural temporal cut-off frequency in a nocturnal spider. ACTA ACUST UNITED AC 2012; 214:3658-63. [PMID: 21993795 DOI: 10.1242/jeb.060855] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We investigated changes in the eye muscle activity in the spider Cupiennius salei as a response to temporal intensity modulations. These spiders are known to enhance eye muscle activity in their principal eyes when moving stimuli are detected in the secondary eyes. We measured the activity of the dorsal eye muscle using a small telemetric unit attached to the spiders' prosoma and confronted the animals to flicker stimuli presented on a cathode ray tube monitor. We registered a significant increase in eye muscle activity as response to temporal light intensity modulations, which implies that no directed motion is required to trigger the spiders' response. This allowed the determination of the behavioural temporal cut-off frequency. None of the frequencies higher than 8.6 cycles s(-1) and all of the frequencies lower than 4.3 cycles s(-1) elicited a significant increase in eye muscle activity. A behavioural cut-off frequency of only a few cycles per second is well in line with the temporal properties of the photoreceptor cells determined using intracellular recordings. A relatively low temporal resolution and a relatively high spatial resolution suit well C. salei's lifestyle as a nocturnal sit-and-wait hunter.
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Affiliation(s)
- Lisa M Fenk
- Department of Neurobiology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Wien, Austria.
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Lehmann T, Hess M, Melzer RR. Wiring a periscope--ocelli, retinula axons, visual neuropils and the ancestrality of sea spiders. PLoS One 2012; 7:e30474. [PMID: 22279594 PMCID: PMC3261207 DOI: 10.1371/journal.pone.0030474] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 12/19/2011] [Indexed: 11/19/2022] Open
Abstract
The Pycnogonida or sea spiders are cryptic, eight-legged arthropods with four median ocelli in a 'periscope' or eye tubercle. In older attempts at reconstructing phylogeny they were Arthropoda incertae sedis, but recent molecular trees placed them as the sister group either to all other euchelicerates or even to all euarthropods. Thus, pycnogonids are among the oldest extant arthropods and hold a key position for the understanding of arthropod evolution. This has stimulated studies of new sets of characters conductive to cladistic analyses, e.g. of the chelifores and of the hox gene expression pattern. In contrast knowledge of the architecture of the visual system is cursory. A few studies have analysed the ocelli and the uncommon "pseudoinverted" retinula cells. Moreover, analyses of visual neuropils are still at the stage of Hanström's early comprehensive works. We have therefore used various techniques to analyse the visual fibre pathways and the structure of their interrelated neuropils in several species. We found that pycnogonid ocelli are innervated to first and second visual neuropils in close vicinity to an unpaired midline neuropil, i.e. possibly the arcuate body, in a way very similar to ancestral euarthropods like Euperipatoides rowelli (Onychophora) and Limulus polyphemus (Xiphosura). This supports the ancestrality of pycnogonids and sheds light on what eyes in the pycnogonid ground plan might have 'looked' like. Recently it was suggested that arthropod eyes originated from simple ocelli similar to larval eyes. Hence, pycnogonid eyes would be one of the early offshoots among the wealth of more sophisticated arthropod eyes.
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Stegner MEJ, Richter S. Morphology of the brain in Hutchinsoniella macracantha (Cephalocarida, Crustacea). ARTHROPOD STRUCTURE & DEVELOPMENT 2011; 40:221-243. [PMID: 21679884 DOI: 10.1016/j.asd.2011.04.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 04/18/2011] [Accepted: 04/18/2011] [Indexed: 05/30/2023]
Abstract
External morphological features of Cephalocarida have long been interpreted as plesiomorphic with regard to those of other crustaceans. Based on transmission electron microscopy and light microscopy, however, the brain in the cephalocarid Hutchinsoniella macracantha has been shown to contain a number of structures that are more difficult to interpret in an evolutionary context. These include the multi-lobed complex, a unique cluster of neuropils associated with the olfactory lobes. To establish a well-founded comparison of phylogenetically relevant, neuroanatomical data from Cephalocarida to other arthropods, we investigated the brain in H. macracantha using immunolabeling (acetylated α-tubulin, serotonin, RFamide, histamine) and nuclear counter stains of whole mounts and vibratome sections analyzing specimens with confocal laser scanning microscopy and computer-aided 3D-reconstruction. Other 3D-reconstructions were based on serial 1 μm semi-thin sections. The multi-lobed complex features a pedunculus and shows detailed homologies with the mushroom bodies of certain Insecta and Lithobiomorpha (Chilopoda), suggesting that the hemiellipsoid bodies in Remipedia and Malacostraca have derived from a cephalocarid-like pattern. Like the corresponding tracts in Insecta, the olfactory globular tracts linking the multi-lobed complex to the olfactory lobes are ipsilateral, probably constituting the plesiomorphic pattern from which the decussating tracts in Remipedia and Malacostraca have evolved. The olfactory lobes in H. macracantha are uniquely organized into vertical stacks of olfactory glomeruli whose exact shape could not be identified. Similarly to Malacostraca and Insecta, the olfactory glomeruli in H. macracantha are innervated by serotonin-like, RFamide-like, and histamine-like immunoreactive interneurons. This suggests homology of the olfactory lobes across Tetraconata, despite the different morphological organization. Although H. macracantha lacks elongated, unpaired midline neuropils known from the protocerebrum of other Arthropoda, the possible rudiment of a central-body-like neuropil that receives decussating fibers from anterior somata was revealed by the serotonin-like immunoreactive pattern.
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Affiliation(s)
- Martin E J Stegner
- Institut für Biowissenschaften, Abteilung Allgemeine und Spezielle Zoologie, Universität Rostock, Universitätsplatz 2, 18055 Rostock, Germany.
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Loesel R, Seyfarth EA, Bräunig P, Agricola HJ. Neuroarchitecture of the arcuate body in the brain of the spider Cupiennius salei (Araneae, Chelicerata) revealed by allatostatin-, proctolin-, and CCAP-immunocytochemistry and its evolutionary implications. ARTHROPOD STRUCTURE & DEVELOPMENT 2011; 40:210-220. [PMID: 21256976 DOI: 10.1016/j.asd.2011.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 01/03/2011] [Accepted: 01/06/2011] [Indexed: 05/30/2023]
Abstract
Here we describe the neuronal organization of the arcuate body in the brain of the wandering spider Cupiennius salei. The internal anatomy of this major brain center is analyzed in detail based on allatostatin-, proctolin-, and crustacean cardioactive peptide (CCAP)-immunohistochemistry. Prominent neuronal features are demonstrated in graphic reconstructions. The stainings revealed that the neuroarchitecture of the arcuate body is characterized by several distinct layers some of which comprise nerve terminals that are organized in columnar, palisade-like arrays. The anatomy of the spider's arcuate body exhibits similarities as well as differences when compared to the central complex in the protocerebrum of the Tetraconata. Arguments for and against a possible homology of the arcuate body of the Chelicerata and the central complex of the Tetraconata and their consequences for the understanding of arthropod brain evolution are discussed.
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Affiliation(s)
- Rudi Loesel
- Institut für Biologie II (Zoologie) der Rheinisch-Westfaelischen Technischen Hochschule, D-52074 Aachen, Germany.
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Schmid A, Trischler C. Active sensing in a freely walking spider: look where to go. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:494-500. [PMID: 21281645 DOI: 10.1016/j.jinsphys.2011.01.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 01/21/2011] [Accepted: 01/24/2011] [Indexed: 05/30/2023]
Abstract
The Central American hunting spider Cupiennius salei, like most other spiders, has eight eyes, one pair of principal eyes and three pairs of secondary eyes. The principal eyes and one pair of the secondary eyes have almost completely overlapping visual fields, and presumably differ in function. The retinae of the principal eyes can be moved independently by two pairs of eye muscles each, whereas the secondary eyes do not have such eye muscles. The behavioural relevance of retinal movements of freely moving spiders was investigated by a novel dual-channel telemetric registration of the eye muscle activities. Walking spiders shifted the ipsilateral retina with respect to the walking direction before, during and after a turning movement. The change in the direction of vision in the ipsilateral anterior median eye was highly correlated with the walking direction, regardless of the actual light conditions. The contralateral retina remained in its resting position. This indicates that Cupiennius salei shifts it visual field in the walking direction not only during but sometimes previous to an intended turn, and therefore "peers" actively into the direction it wants to turn.
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Affiliation(s)
- A Schmid
- Department of Neurobiology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Wien, Austria.
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Fenk LM, Schmid A. The orientation-dependent visual spatial cut-off frequency in a spider. J Exp Biol 2010; 213:3111-7. [DOI: 10.1242/jeb.041939] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Cupiennius salei (Araneae, Ctenidae) has, like most spiders, eight camera-type eyes. The anterior median eyes are called principal eyes and have a movable retina; all of the other eyes are referred to as secondary eyes and are equipped with a reflecting tapetum. The photoreceptors in the secondary eyes are arranged in rows on the tapetum and the inter-receptor angle along such a row is smaller than normal to it. In this study, the vertical and horizontal spatial cut-off frequencies of moving gratings were measured for the posterior median (PM) eyes, and the data were then compared with the anatomical data reported in the literature. Detection of moving objects in the secondary eyes enhances the eye muscle potential frequency in the principal eyes. We thus recorded the eye muscle activity with a telemetric unit as a monitor for motion detection while moving stimuli – sinusoidally modulated bright and dark stripes – were presented to the PM eyes on a computer screen. A significant increase in the eye muscle activity was measured for gratings at an angular wavelength of 2.0 deg in the vertical orientation and of 2.7 deg in the horizontal direction. In the vertical orientation the critical wavelength is twice the inter-receptor angle; in the horizontal orientation the spiders responded to wavelengths that are smaller than twice the corresponding inter-receptor angle. The cut-off frequency seems thus to be limited by the visual field of the photoreceptors rather than the inter-receptor angle. The relative intensity modulations modelled for the two different grating orientations in single photoreceptor cells were in line with our data.
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Affiliation(s)
- Lisa M. Fenk
- Department of Neurobiology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Wien, Austria
| | - Axel Schmid
- Department of Neurobiology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Wien, Austria
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Fenk LM, Hoinkes T, Schmid A. Vision as a third sensory modality to elicit attack behavior in a nocturnal spider. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2010; 196:957-61. [PMID: 20820788 DOI: 10.1007/s00359-010-0575-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 08/16/2010] [Accepted: 08/16/2010] [Indexed: 11/28/2022]
Abstract
Cupiennius salei (Ctenidae) has been extensively studied for many years and is probably the only spider that presently can be considered a model organism for neuro-ethology. The night-active spiders have been shown to predominantly rely on their excellent mechano-sensory systems for courtship and prey capture, whereas vision was assumed to play a minor role, if any, in these behavioral contexts. Using slowly moving discs presented on a computer screen it could be shown for the first time that visual stimuli alone can elicit attack behavior (abrupt approaching reactions) in these spiders as well. These observations suggest that visual information could be used by the spiders to elicit and guide predatory behavior. Attack behavior in Cupiennius salei can thus be triggered independently by three sensory modalities--substrate vibrations, airflow stimuli, and visual cues--and offers an interesting model system to study the interactions of multimodal sensory channels in complex behavior.
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Affiliation(s)
- L M Fenk
- Department of Neurobiology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
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Tomer R, Denes AS, Tessmar-Raible K, Arendt D. Profiling by Image Registration Reveals Common Origin of Annelid Mushroom Bodies and Vertebrate Pallium. Cell 2010; 142:800-9. [DOI: 10.1016/j.cell.2010.07.043] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 05/22/2010] [Accepted: 07/14/2010] [Indexed: 01/08/2023]
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Loesel R, Heuer CM. The mushroom bodies â prominent brain centres of arthropods and annelids with enigmatic evolutionary origin. ACTA ZOOL-STOCKHOLM 2010. [DOI: 10.1111/j.1463-6395.2009.00422.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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