scholarly journals Neuronal patterning of the tubular collar cord is highly conserved among enteropneusts but dissimilar to the chordate neural tube

2017 ◽  
Author(s):  
Sabrina Kaul-Strehlow ◽  
Makoto Urata ◽  
Daniela Praher ◽  
Andreas Wanninger
Keyword(s):  
Nervous System ◽  
Neural Tube ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Comparative Analyses ◽  
Dorsal Neural Tube ◽  
Saccoglossus Kowalevskii ◽  
Patterning Genes

AbstractThe dorsal neural tube of chordates and the ventral nerve cord of annelids exhibit a similar molecular mediolateral architecture. Accordingly, the presence of such a complex nervous system (CNS) has been proposed for their last common ancestor. Members of Enteropneusta, a group of non-chordate deuterostomes, possess a less complex CNS including a hollow neural tube, whereby homology to its chordate counterpart remains elusive. Since the majority of data on enteropneusts stem from Saccoglossus kowalevskii, a derived direct-developer, we investigated expression of key neuronal patterning genes in the indirect-developer Balanoglossus misakiensis.The collar cord of B. misakiensis shows anterior Six3/6 and posterior Otx + engrailed expression, in a region corresponding to the chordate brain. Neuronal Nk2.1/Nk2.2 expression is absent. Interestingly, we found median Dlx and lateral Pax6 expression domains, i.e., a condition that is reversed compared to chordates.Comparative analyses reveal that CNS patterning is highly conserved among enteropneusts. BmiDlx and BmiPax6 have no corresponding expression domains in the chordate brain, which may be indicative of independent acquisition of a tubular CNS in Enteropneusta and Chordata. Moreover, mediolateral architecture varies considerably among chordates and enteropneusts, questioning the presence of a vertebrate-like patterned nervous system in the last common deuterostome ancestor.

Distribution of gamma-aminobutyric acid (GABA) in the central nervous system of the male mud crab, Scylla olivacea

Crustaceana ◽  
2020 ◽  
Vol 93 (9-10) ◽  
pp. 1123-1134
Author(s):  
Kanjana Khornchatri ◽  
Jirawat Saetan ◽  
Sirirak Mukem ◽  
Prasert Sobhon ◽  
Tipsuda Thongbuakaew
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Distribution Pattern ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Mud Crab ◽  
Decapod Crustaceans ◽  
The Central Nervous System

Abstract Gamma-aminobutyric acid (GABA) is a neurotransmitter that is widely spread in vertebrate and invertebrate nervous systems and modulates essential physiological roles. Previous studies have reported the distribution of several neurotransmitters throughout the central nervous system (CNS) of decapod crustaceans. However, the existence and distribution of GABA in the mud crab’s, Scylla olivacea, CNS has still not been reported. In this study, we investigated the distribution of GABA using immunohistochemistry. The result revealed that GABA immunoreactivity (-ir) was observed in neurons and fibres throughout the CNS, including the eyestalk, brain, and ventral nerve cord of S. olivacea. Therefore, the existence and extensive distribution pattern of GABA in the CNS of the male mud crab suggest its possible roles in feeding, locomotion, and also reproduction.

First detection of serotonin in the nervous system of the marine calanoid copepod Centropages typicus

2005 ◽  
Vol 85 (1) ◽  
pp. 71-72 ◽  
Author(s):  
D. Benzid ◽  
C. Morris ◽  
R.-M. Barthélémy
Keyword(s):  
Nervous System ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Calanoid Copepod ◽  
Marine Species ◽  
Biological Processes ◽  
Calanoid Copepods ◽  
The Brain ◽  
Serotoninergic Nervous System ◽  
Centropages Typicus

This investigation constitutes the first study of the serotoninergic nervous system in calanoid copepods (crustaceans). Serotonin (5-HT), a neurotransmitter which plays a part in many biological processes, has been detected by immunofluorescence in the brain, the circumoesophageal collar and the ventral nerve cord of the marine species Centropages typicus.

scholarly journals The evolution of nervous system centralization

2008 ◽  
Vol 363 (1496) ◽  
pp. 1523-1528 ◽  
Author(s):  
Detlev Arendt ◽  
Alexandru S Denes ◽  
Gáspár Jékely ◽  
Kristin Tessmar-Raible
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Molecular Architecture ◽  
Molecular Studies ◽  
The Central Nervous System ◽  
Molecular Anatomy ◽  
Set Up ◽  
Insight Into

It is yet unknown when and in what form the central nervous system in Bilateria first came into place and how it further evolved in the different bilaterian phyla. To find out, a series of recent molecular studies have compared neurodevelopment in slow-evolving deuterostome and protostome invertebrates, such as the enteropneust hemichordate Saccoglossus and the polychaete annelid Platynereis . These studies focus on the spatially different activation and, when accessible, function of genes that set up the molecular anatomy of the neuroectoderm and specify neuron types that emerge from distinct molecular coordinates. Complex similarities are detected, which reveal aspects of neurodevelopment that most likely occurred already in a similar manner in the last common ancestor of the bilaterians, Urbilateria. This way, different aspects of the molecular architecture of the urbilaterian nervous system are reconstructed and yield insight into the degree of centralization that was in place in the bilaterian ancestors.

Digger wasp predatory behavior (Hymenoptera, Sphecidae): fly hunting and capture by Oxybelus uniglumis (Crabroninae: Oxybelini); a case of extremely concentrated stinging pattern and prey nervous system

1979 ◽  
Vol 57 (5) ◽  
pp. 953-962 ◽  
Author(s):  
A. L. Steiner
Keyword(s):  
Nervous System ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Ventral Side ◽  
Predatory Behavior ◽  
The State ◽  
Thoracic Segment ◽  
Subesophageal Ganglion ◽  
Digger Wasp ◽  
Single Mass

Several Orthoptera-hunting wasps usually deliver four paralyzing stings to their prey (one for each thoracic segment and one for the ventral side of the neck) in a predictable, although not immutable, order. This also matches the number of thoracic ganglia of the ventral nerve cord and leg pairs plus the subesophageal ganglion that controls the potentially dangerous mandibles. Oxybelus wasps usually deliver only one thoracic sting, behind one foreleg base, and no neck sting. Many flies have only a single mass of fused ganglia in the thorax, no subesophageal ganglion, and no potentially dangerous mouthparts. Furthermore, some Oxybelus wasps use the sting for prey carriage. The number of thoracic stings matches the number of thoracic ganglionic masses (one), rather than the number of leg pairs (three), thoracic segments (three), or pairs of easily punctured soft membranes (three). This case of extremely reduced paralyzing sequence and prey nervous system is discussed from an evolutionary standpoint and compared with cases in which less or no such reduction occurred. Correlative differences in the state of the prey are also considered.

scholarly journals Whole-central nervous system functional imaging in larval Drosophila

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
William C. Lemon ◽  
Stefan R. Pulver ◽  
Burkhard Höckendorf ◽  
Katie McDole ◽  
Kristin Branson ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Activity Patterns ◽  
Network Activity ◽  
Imaging Data ◽  
Spatiotemporal Resolution ◽  
Functional Connections ◽  
The Brain

Abstract Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS. We present a method for measuring activity in an entire, non-transparent CNS with high spatiotemporal resolution. We combine a light-sheet microscope capable of simultaneous multi-view imaging at volumetric speeds 25-fold faster than the state-of-the-art, a whole-CNS imaging assay for the isolated Drosophila larval CNS and a computational framework for analysing multi-view, whole-CNS calcium imaging data. We image both brain and ventral nerve cord, covering the entire CNS at 2 or 5 Hz with two- or one-photon excitation, respectively. By mapping network activity during fictive behaviours and quantitatively comparing high-resolution whole-CNS activity maps across individuals, we predict functional connections between CNS regions and reveal neurons in the brain that identify type and temporal state of motor programs executed in the ventral nerve cord.

The Ordovician fossil Lagynocystis pyramidalis (Barrande) and the ancestry of amphioxus

1973 ◽  
Vol 265 (871) ◽  
pp. 409-469 ◽  
Keyword(s):  
Nervous System ◽  
Nerve Cord ◽  
Common Ancestor ◽  
Buccal Cavity ◽  
Cranial Nerves ◽  
Lower Ordovician ◽  
Upward Growth ◽  
Dorsal Nerve ◽  
Left And Right ◽  
The Right

Lagynocystis pyramidalis (Barrande) from the marine Lower Ordovician of Bohemia (Šárka Formation (Llanvirn)), has features which suggest that it is ancestral, or nearly so, to living cephalochordates such as amphioxus ( Branchiostoma ). L. pyramidalis belongs to a strange group of fossils classified by some workers as ‘carpoid’ echinoderms (phylum Echinodermata, subphylum Homalozoa, class Stylophora). They are better seen, however, as primitive chordates with echinoderm affinities (phylum Chordata, subphylum Calcichordata Jefferies, 1967, class Stylophora). The most striking echinoderm-like feature of the calcichordates is their calcite skeleton with each plate a single crystal of calcite. Their chordate characters include: (1) branchial slits; (2) a postanal tail (stem) with muscle blocks, notochord, dorsal nerve cord and segmental ganglia; (3) a brain and cranial nervous system like those of a fish; and (4) various asymmetries like those of recent primitive chordates. The calcichordates are divided into a more primitive order, Cornuta, and a more advanced order Mitrata, which evolved from Cornuta. L. pyramidalis is a specialized member of the order Mitrata. Forms up till now associated with it in the suborder Lagynocystida of the Mitrata are better separated from it to form a new suborder Peltocystida (Kirkocystidae plus Peltocystidae). The features which ally L. pyramidalis to amphioxus are as follows: (1) a median ventral atrium opening by a median ventral atriopore; (2) a probably excretory posterior coelom which could give rise to the nephridia of amphioxus by upward growth of the gill slits; (3) evidence that the anus opened externally on the left; (4) evidence that the mouth and buccal cavity was innervated more strongly from the left than from the right; (5) evidence suggesting that, if it swam, L. pyramidalis would rotate about its long axis, clockwise as seen from behind, like late larval amphioxus and larval tunicates. The amphioxus-like features of L. pyramidalis are imposed on the pattern of a very primitive mitrate. There existed thus: (1) a well-developed brain and the cranial nerves were more of the vertebrate pattern than those of amphioxus; (2) left and right branchial openings in addition to the median atriopore; and (3) the tail or stem had paired segmental ganglia. The latest common ancestor of vertebrates and amphioxus would be a primitive mitrate. It follows, since Lagynocystis had a calcite skeleton, that such a skeleton has been lost at least twice in the evolution of the chordates.

scholarly journals A single neuron subset governs a single coactive neuron circuit in Hydra vulgaris, representing a possible ancestral feature of neural evolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yukihiko Noro ◽  
Hiroshi Shimizu ◽  
Katsuhiko Mineta ◽  
Takashi Gojobori
Keyword(s):  
Nervous System ◽  
Common Ancestor ◽  
Model Organism ◽  
The Body ◽  
Neural Function ◽  
Last Common Ancestor ◽  
Longitudinal Contraction ◽  
Hydra Vulgaris ◽  
Motor Circuits ◽  
Neural Evolution

AbstractThe last common ancestor of Bilateria and Cnidaria is believed to be one of the first animals to develop a nervous system over 500 million years ago. Many of the genes involved in the neural function of the advanced nervous system in Bilateria are well conserved in Cnidaria. Thus, the cnidarian Hydra vulgaris is a good model organism for the study of the putative primitive nervous system in its last common ancestor. The diffuse nervous system of Hydra consists of several peptidergic neuron subsets. However, the specific functions of these subsets remain unclear. Using calcium imaging, here we show that the neuron subsets that express neuropeptide, Hym-176, function as motor circuits to evoke longitudinal contraction. We found that all neurons in a subset defined by the Hym-176 gene (Hym-176A) or its paralogs (Hym-176B) expression are excited simultaneously, followed by longitudinal contraction. This indicates not only that these neuron subsets have a motor function but also that a single molecularly defined neuron subset forms a single coactive circuit. This is in contrast with the bilaterian nervous system, where a single molecularly defined neuron subset harbors multiple coactive circuits, showing a mixture of neurons firing with different timings. Furthermore, we found that the two motor circuits, one expressing Hym-176B in the body column and the other expressing Hym-176A in the foot, are coordinately regulated to exert region-specific contraction. Our results demonstrate that one neuron subset is likely to form a monofunctional circuit as a minimum functional unit to build a more complex behavior in Hydra. This simple feature (one subset, one circuit, one function) found in Hydra may represent the simple ancestral condition of neural evolution.

Sign in / Sign up

Export Citation Format

Share Document