Atlas of the Neuromuscular System in the Trachymedusa Aglantha digitale: Insights from the advanced hydrozoan

Mapping Intimacies ◽

10.1101/772418 ◽

2019 ◽

Author(s):

Tigran P. Norekian ◽

Leonid L. Moroz

Keyword(s):

Parallel Evolution ◽

Neural Systems ◽

Striated Muscles ◽

Reference Species ◽

Feeding Behaviors ◽

Fully Integrated ◽

Neuronal Markers ◽

Giant Axons ◽

Complex Organization ◽

Escape Behaviors

ABSTRACTCnidaria is the sister taxon to bilaterian animals, and therefore, represents a key reference lineage to understand early origins and evolution of the neural systems. The hydromedusa Aglantha digitale is arguably the best electrophysiologically studied jellyfish because of its system of giant axons and unique fast swimming/escape behaviors. Here, using a combination of scanning electron microscopy and immunohistochemistry together with phalloidin labeling, we systematically characterize both neural and muscular systems in Aglantha, summarizing and expanding further the previous knowledge on the microscopic neuroanatomy of this crucial reference species. We found that the majority, if not all (∼2500) neurons, that are labeled by FMRFamide antibody are different from those revealed by anti-α-tubulin immunostaining, making these two neuronal markers complementary to each other and, therefore, expanding the diversity of neural elements in Aglantha with two distinct neural subsystems. Our data uncovered the complex organization of neural networks forming a functional ‘annulus-type’ central nervous system with three subsets of giant axons, dozen subtypes of neurons, muscles and a variety of receptors fully integrated with epithelial conductive pathways supporting swimming, escape and feeding behaviors. The observed unique adaptations within the Aglantha lineage (including giant axons innervating striated muscles) strongly support an extensive and wide-spread parallel evolution of integrative and effector systems across Metazoa.

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Hybrid Neural Architecture for Intelligent Recommender System Classification Unit Design

Intelligent Techniques in Recommendation Systems ◽

10.4018/978-1-4666-2542-6.ch010 ◽

2013 ◽

pp. 192-213

Author(s):

Emmanuel Buabin

Keyword(s):

Recommender System ◽

Document Classification ◽

Research Field ◽

Neural Systems ◽

Fully Integrated ◽

Text Document ◽

Unit Design ◽

Boosting Algorithms ◽

New Research ◽

Text Document Classification

The objective is intelligent recommender system classification unit design using hybrid neural techniques. In particular, a neuroscience-based hybrid neural by Buabin (2011a) is introduced, explained, and examined for its potential in real world text document classification on the modapte version of the Reuters news text corpus. The so described neuroscience model (termed Hy-RNC) is fully integrated with a novel boosting algorithm to augment text document classification purposes. Hy-RNC outperforms existing works and opens up an entirely new research field in the area of machine learning. The main contribution of this book chapter is the provision of a step-by-step approach to modeling the hybrid system using underlying concepts such as boosting algorithms, recurrent neural networks, and hybrid neural systems. Results attained in the experiments show impressive performance by the hybrid neural classifier even with a minimal number of neurons in constituting structures.

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The Neural Basis of Escape Behavior in Vertebrates

Annual Review of Neuroscience ◽

10.1146/annurev-neuro-100219-122527 ◽

2020 ◽

Vol 43 (1) ◽

pp. 417-439 ◽

Cited By ~ 3

Author(s):

Tiago Branco ◽

Peter Redgrave

Keyword(s):

Neural Circuits ◽

Escape Behavior ◽

Building Blocks ◽

Normative Theory ◽

Neural Systems ◽

Adaptive Behaviors ◽

Neural Basis ◽

Sensory Stimuli ◽

Evolutionarily Conserved ◽

Escape Behaviors

Escape is one of the most studied animal behaviors, and there is a rich normative theory that links threat properties to evasive actions and their timing. The behavioral principles of escape are evolutionarily conserved and rely on elementary computational steps such as classifying sensory stimuli and executing appropriate movements. These are common building blocks of general adaptive behaviors. Here we consider the computational challenges required for escape behaviors to be implemented, discuss possible algorithmic solutions, and review some of the underlying neural circuits and mechanisms. We outline shared neural principles that can be implemented by evolutionarily ancient neural systems to generate escape behavior, to which cortical encephalization has been added to allow for increased sophistication and flexibility in responding to threat.

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Biodiversity Meets Neuroscience: From the Sequencing Ship (Ship-Seq) to Deciphering Parallel Evolution of Neural Systems in Omic’s Era

Integrative and Comparative Biology ◽

10.1093/icb/icv084 ◽

2015 ◽

pp. icv084 ◽

Cited By ~ 3

Author(s):

Leonid L. Moroz

Keyword(s):

Parallel Evolution ◽

Neural Systems

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Independent origins of neurons and synapses: insights from ctenophores

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2015.0041 ◽

2016 ◽

Vol 371 (1685) ◽

pp. 20150041 ◽

Cited By ~ 80

Author(s):

Leonid L. Moroz ◽

Andrea B. Kohn

Keyword(s):

Parallel Evolution ◽

Neural System ◽

Neural Systems ◽

Gamma Aminobutyric Acid ◽

Metabolomics Data ◽

Cell Lineages ◽

Signalling Molecules ◽

Single Character ◽

Chemical Synapses ◽

Intercellular Messenger

There is more than one way to develop neuronal complexity, and animals frequently use different molecular toolkits to achieve similar functional outcomes. Genomics and metabolomics data from basal metazoans suggest that neural signalling evolved independently in ctenophores and cnidarians/bilaterians. This polygenesis hypothesis explains the lack of pan-neuronal and pan-synaptic genes across metazoans, including remarkable examples of lineage-specific evolution of neurogenic and signalling molecules as well as synaptic components. Sponges and placozoans are two lineages without neural and muscular systems. The possibility of secondary loss of neurons and synapses in the Porifera/Placozoa clades is a highly unlikely and less parsimonious scenario. We conclude that acetylcholine, serotonin, histamine, dopamine, octopamine and gamma-aminobutyric acid (GABA) were recruited as transmitters in the neural systems in cnidarian and bilaterian lineages. By contrast, ctenophores independently evolved numerous secretory peptides, indicating extensive adaptations within the clade and suggesting that early neural systems might be peptidergic. Comparative analysis of glutamate signalling also shows numerous lineage-specific innovations, implying the extensive use of this ubiquitous metabolite and intercellular messenger over the course of convergent and parallel evolution of mechanisms of intercellular communication. Therefore: (i) we view a neuron as a functional character but not a genetic character, and (ii) any given neural system cannot be considered as a single character because it is composed of different cell lineages with distinct genealogies, origins and evolutionary histories. Thus, when reconstructing the evolution of nervous systems, we ought to start with the identification of particular cell lineages by establishing distant neural homologies or examples of convergent evolution. In a corollary of the hypothesis of the independent origins of neurons, our analyses suggest that both electrical and chemical synapses evolved more than once.

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An immunohistochemical study of ovarian innervation in the emu (Dromaius novaehollandiae)

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v75i1.89 ◽

2008 ◽

Vol 75 (1) ◽

Cited By ~ 8

Author(s):

M–.C. Madekurozwa

Keyword(s):

Neuron Specific Enolase ◽

Neuronal Cell ◽

Neural System ◽

Neural Systems ◽

Neurofilament Protein ◽

Neuronal Markers ◽

Protein Gene Product ◽

Neuronal Cell Bodies ◽

Dromaius Novaehollandiae ◽

Nerve Bundles

The present study investigated the distribution of nerves in the ovary of the emu. The neuronal markers, protein gene product 9.5, neurofilament protein and neuron specific enolase demonstrated the constituents of the extrinsic and intrinsic ovarian neural systems. The extrinsic neural system was composed of ganglia in the ovarian stalk, as well as nerve bundles, which were distributed throughout the ovary. Isolated neuronal cell bodies, in the medulla and cortex, formed the intrinsic neural system. An interesting finding of the study was the presence of nerve bundles, circumscribed by lymphocytes, in the ovarian stalk. The findings of the study indicate that the distribution of nerve fibres and neuronal cell bodies in the emu ovary is similar, but not identical to that of the domestic fowl and ostrich.

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Parallel evolution of direct development in frogs – Skin and thyroid gland development in African Squeaker Frogs (Anura: Arthroleptidae: Arthroleptis)

10.1101/2020.09.07.286476 ◽

2020 ◽

Author(s):

Benjamin Naumann ◽

Susan Schweiger ◽

Jörg U. Hammel ◽

Hendrik Müller

Keyword(s):

Thyroid Hormone ◽

Thyroid Gland ◽

Parallel Evolution ◽

Direct Development ◽

Feeding Behaviors ◽

Developmental Constraints ◽

Organ Systems ◽

Evolutionary Trajectories ◽

Gland Development ◽

Thyroid Gland Activity

AbstractCases of parallel evolution offer the possibility to identify adaptive traits and to uncover developmental constraints on the evolutionary trajectories of these traits. The independent evolution of direct development, from the ancestral biphasic life history in frogs is such a case of parallel evolution. In frogs, aquatic larvae (tadpoles) differ profoundly from their adult forms and exhibit a stunning diversity regarding their habitats, morphology and feeding behaviors. The transition from the tadpole to the adult is a climactic, thyroid hormone (TH)-dependent process of profound and fast morphological rearrangement called metamorphosis. One of the organ systems that experiences the most comprehensive metamorphic rearrangements is the skin. Direct-developing frogs lack a free-swimming tadpole and hatch from terrestrial eggs as fully formed froglets. In the few species examined, development is characterized by the condensed and transient formation of some tadpole-specific features and the early formation of adult-specific features during a “cryptic” metamorphosis. In this study we show that skin in direct-developing African squeaker frogs (Arthroleptis) is also repatterned from a tadpole-like to an adult-like histology during a cryptic metamorphosis. This repatterning correlates with an increase of thyroid gland activity. A comparison with data from the Puerto Rican coqui (Eleutherodactylus coqui) reveals that direct development might have evolved in parallel in these frogs by a comparable heterochronic shift of thyroid gland activity. This suggests that the development of many adult-features is still constrained by the ancestral dependency on thyroid hormone signaling.

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Distribution of c-protein isoforms in sarcomeres of developing chick skeletal muscle

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010319x ◽

1988 ◽

Vol 46 ◽

pp. 226-227

Author(s):

D. A. Fischman ◽

J. E. Dennis ◽

T. Obinata ◽

H. Takano-Ohmuro

Keyword(s):

Skeletal Muscles ◽

Thick Filament ◽

Protein Isoforms ◽

Actin Binding ◽

Striated Muscles ◽

C Protein ◽

Sarcomeric Protein ◽

Thick Filaments ◽

Cross Bridges ◽

Bridge Bearing

C-protein is a 150 kDa protein found within the A bands of all vertebrate cross-striated muscles. By immunoelectron microscopy, it has been demonstrated that C-protein is distributed along a series of 7-9 transverse stripes in the medial, cross-bridge bearing zone of each A band. This zone is now termed the C-zone of the sarcomere. Interest in this protein has been sparked by its striking distribution in the sarcomere: the transverse repeat between C-protein stripes is 43 nm, almost exactly 3 times the 14.3 nm axial repeat of myosin cross-bridges along the thick filaments. The precise packing of C-protein in the thick filament is still unknown. It is the only sarcomeric protein which binds to both myosin and actin, and the actin-binding is Ca-sensitive. In cardiac and slow, but not fast, skeletal muscles C-protein is phosphorylated. Amino acid composition suggests a protein of little or no αhelical content. Variant forms (isoforms) of C-protein have been identified in cardiac, slow and embryonic muscles.

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FR-IR Molecular Microanalysis System

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134958 ◽

1990 ◽

Vol 48 (2) ◽

pp. 270-271

Author(s):

John A. Reffner ◽

William T. Wihlborg

Keyword(s):

Fourier Transform ◽

Fourier Transform Infrared ◽

Integrated System ◽

Morphological Examination ◽

Fully Integrated ◽

Ir Microscopy ◽

Normal Functions ◽

Infrared Microspectroscopy ◽

Infrared Spectral ◽

Ft Ir

The IRμs™ is the first fully integrated system for Fourier transform infrared (FT-IR) microscopy. FT-IR microscopy combines light microscopy for morphological examination with infrared spectroscopy for chemical identification of microscopic samples or domains. Because the IRμs system is a new tool for molecular microanalysis, its optical, mechanical and system design are described to illustrate the state of development of molecular microanalysis. Applications of infrared microspectroscopy are reviewed by Messerschmidt and Harthcock.Infrared spectral analysis of microscopic samples is not a new idea, it dates back to 1949, with the first commercial instrument being offered by Perkin-Elmer Co. Inc. in 1953. These early efforts showed promise but failed the test of practically. It was not until the advances in computer science were applied did infrared microspectroscopy emerge as a useful technique. Microscopes designed as accessories for Fourier transform infrared spectrometers have been commercially available since 1983. These accessory microscopes provide the best means for analytical spectroscopists to analyze microscopic samples, while not interfering with the FT-IR spectrometer’s normal functions.

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