A comparative analysis of the nervous system of cheilostome bryozoans

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Jakob Prömer ◽  
Andy Sombke ◽  
Thomas Schwaha
Keyword(s):  
Nervous System ◽  
Mouth Opening ◽  
Cerebral Ganglion ◽  
Nerve Ring ◽  
The Body ◽  
Ground Pattern ◽  
Freshwater Habitats ◽  
Peripheral Areas ◽  
Cheilostome Bryozoans ◽  
Anal Side

Abstract Background Bryozoans are sessile aquatic suspension feeders in mainly marine, but also freshwater habitats. Most species belong to the marine and calcified Cheilostomata. Since this taxon remains mostly unstudied regarding its neuroanatomy, the focus of this study is on the characterization and ground pattern reconstruction of the autozooidal nervous system based on six representatives. Results A common neuronal innervation pattern is present in the investigated species: a cerebral ganglion is located at the base of the lophophore, from where neurite bundles embrace the mouth opening to form a circumoral nerve ring. Four neurite bundles project from the cerebral ganglion to innervate peripheral areas, such as the body wall and parietal muscles via the tentacle sheath. Five neurite bundles comprise the main innervation of the visceral tract. Four neurite bundles innervate each tentacle via the circumoral nerve ring. Mediofrontal tentacle neurite bundles emerge directly from the nerve ring. Two laterofrontal- and one abfrontal tentacle neurite bundles emanate from radial neurite bundles, which originate from the cerebral ganglion and circumoral nerve ring in between two adjacent tentacles. The radial neurite bundles terminate in intertentacular pits and give rise to one abfrontal neurite bundle at the oral side and two abfrontal neurite bundles at the anal side. Similar patterns are described in ctenostome bryozoans. Conclusions The present results thus represent the gymnolaemate situation. Innervation of the tentacle sheath and visceral tract by fewer neurite bundles and tentacular innervation by four to six tentacle neurite bundles support cyclostomes as sister taxon to gymnolaemates. Phylactolaemates feature fewer distinct neurite bundles in visceral- and tentacle sheath innervation, which always split in nervous plexus, and their tentacles have six neurite bundles. Thus, this study supports phylactolaemates as sistergroup to myolaemates.

The Alimentary Canal, its Appendages, Salivary Glands and the Nervous System of the adult Female Lac Insect, Laccifer lacca, Kerr (Coccidae)

1934 ◽  
Vol 25 (4) ◽  
pp. 541-550 ◽  
Author(s):  
P. S. Negi
Keyword(s):  
Nervous System ◽  
Salivary Glands ◽  
Cerebral Ganglion ◽  
Body Cavity ◽  
The Body ◽  
Outer Side ◽  
Ventral Ganglion ◽  
The Central Nervous System ◽  
Colon And Rectum ◽  
Lac Insect

SummaryOwing to the deposition of resin, the females assume two shapes, one somewhat circular in which the mouth-parts are situated ventrally about the middle of the body, and the other pyriform, in which the mouth-parts are situated at the extreme anterior end. In the former type of females the mouth-parts are posteriorly directed and in the latter anteriorly. The rostrum lies outside the body cavity between the anterior pair of oral lobes. The rostralis opens into the pharynx which lies in the tentorium. The oesophagus is elongated and passes into the colo-rectum to be succeeded by the convoluted ventriculus. The ventriculus on leaving the colo-rectum leads into the intestine, which is marked into the mid and hind intestine by the junction of the ampulla of the Malpighian tubes. The intestine after forming a loop round the greater part of the colo-rectum re-enters it close to the point of its commencement from it and continues closely attached to the outer side of the ventriculus from its distal to its proximal end; after this it comes out of the colo-rectum and runs alongside it to open into it near the anterior third of its length. The convolutions inside the colo-rectum are comprised of the ventriculus and the part of the hind intestine running outer to it. The “colon caecum” is absent. The colo-rectum opens at the anus situated at the posterior end of the insect and is divided into colon and rectum by the opening of the intestine into it.The salivary glands consist of two branches of ovoid and spherical bodies. The common duct of the salivary gland of each side runs close to the ventral ganglion and joins the opposite duct to form the terminal duct near its anterior end, which then opens into the pharynx.The nervous system consists of a bilobed cerebral ganglion which lies anteriorly to the mouth-parts in females in which the tentorium is directed posteriorly, and either laterally or ventrally to it in females in which the tentorium is directed anteriorly and lies at the extreme anterior end. The cerebral ganglion is joined by a pair of connectives to the ventral ganglion, which lies dorsal to the tentorium in females in which it is directed posteriorly, and posterior to the tentorium in which it is directed anteriorly and lies at the extreme anterior end. The ventral ganglion is followed by the nerve chord, which varies in length in either type of female. The main nerves arising from the central nervous system are described.

The nervous systems of Tylodelphys metacercariae (Digenea: Diplostomidae) from the catfish Clarias gariepinus (Clariidae) in freshwater habitats of Tanzania

2015 ◽  
Vol 90 (6) ◽  
pp. 712-718
Author(s):  
F.D. Chibwana ◽  
G. Nkwengulila
Keyword(s):  
Nervous System ◽  
Clarias Gariepinus ◽  
Molecular Techniques ◽  
The Body ◽  
Cranial Cavity ◽  
Enzyme Cytochemistry ◽  
Nervous Systems ◽  
Acetylthiocholine Iodide ◽  
Freshwater Habitats ◽  
The Central Nervous System

AbstractThe nervous systems of three Tylodelphys metacercariae (T. mashonense, Tylodelphys spp. 1 and 2) co-occurring in the cranial cavity of the catfish, Clarias gariepinus, were examined by the activity of acetylthiocholine iodide (AcThI), with the aim of better understanding the arrangement of sensillae on the body surface and the nerve trunks and commissures, for taxonomic purposes. Enzyme cytochemistry demonstrated a comparable orthogonal arrangement in the three metacercariae: the central nervous system (CNS) consisting of a pair of cerebral ganglia, from which anterior and posterior neuronal pathways arise and inter-link by cross-connectives and commissures. However, the number of transverse nerves was significantly different in the three diplostomid metacercariae: Tylodelphys sp. 1 (30), Tylodelphys sp. 2 (21) and T. mashonense (15). The observed difference in the nervous system of the three metacercariae clearly separates them into three species. These findings suggest that consistent differences in the transverse nerves of digenean metacercariae could enable the differentiation of metacercariae to the species level in the absence of molecular techniques. This, however, might require further testing on a larger number of species of digenean metacercariae.

scholarly journals A new species of Blatticola Schwenk, 1926 (Oxyurida, Thelastomatidae) a parasite of Anurogryllus muticus (De Geer, 1773) (Orthoptera, Gryllidae) from Argentina

2007 ◽  
Vol 47 (15) ◽  
pp. 181-186 ◽  
Author(s):  
María Fernanda Achinelly ◽  
Nora B. Camino
Keyword(s):  
New Species ◽  
Body Length ◽  
Mouth Opening ◽  
Nerve Ring ◽  
The Body ◽  
The Other ◽  
Smooth Shell ◽  
Small Pore ◽  
Basal Bulb ◽  
A New Species

Blatticola cristovata n. sp. (Oxyurida, Thelastomatidae) a parasite of the cricket Anurogryllus muticus (De Geer, 1773) (Orthoptera, Gryllidae) from Argentina, is described and illustrated. This is the first species of the genus Blatticola found parasitizing cricket. This new species is characterized in females by having the cuticle annulated through the body length, the mouth opening is subtriangular and surrounded by eight cephalic papillae, the stoma is short with three pairs placed in two rows of cuticular sclerotised plates, amphids in small pore shaped, oesophagus is divided into three parts, anterior cylindrical corpus, isthmus distinct, and basal bulb valved, the nerve ring is situated around the middle of corpus, the intestine is wide broad anteriorly, oval eggs, smooth shell, with a straight side, and the other side with a band running longitudinally. Males with one pair of preanal, one pair of adanal and two pairs of postanal papillae, and the tail appendage short, conical and pointed.

scholarly journals Fuxianhuiid ventral nerve cord and early nervous system evolution in Panarthropoda

2016 ◽  
Vol 113 (11) ◽  
pp. 2988-2993 ◽  
Author(s):  
Jie Yang ◽  
Javier Ortega-Hernández ◽  
Nicholas J. Butterfield ◽  
Yu Liu ◽  
George S. Boyan ◽  
...  
Keyword(s):  
Nervous System ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
The Body ◽  
Crown Group ◽  
Ground Pattern ◽  
Exceptional Preservation ◽  
Stem Group ◽  
Nervous System Evolution ◽  
Neurological Features

Panarthropods are typified by disparate grades of neurological organization reflecting a complex evolutionary history. The fossil record offers a unique opportunity to reconstruct early character evolution of the nervous system via exceptional preservation in extinct representatives. Here we describe the neurological architecture of the ventral nerve cord (VNC) in the upper-stem group euarthropodChengjiangocaris kunmingensisfrom the early Cambrian Xiaoshiba Lagerstätte (South China). The VNC ofC. kunmingensiscomprises a homonymous series of condensed ganglia that extend throughout the body, each associated with a pair of biramous limbs. Submillimetric preservation reveals numerous segmental and intersegmental nerve roots emerging from both sides of the VNC, which correspond topologically to the peripheral nerves of extant Priapulida and Onychophora. The fuxianhuiid VNC indicates that ancestral neurological features of Ecdysozoa persisted into derived members of stem-group Euarthropoda but were later lost in crown-group representatives. These findings illuminate the VNC ground pattern in Panarthropoda and suggest the independent secondary loss of cycloneuralian-like neurological characters in Tardigrada and Euarthropoda.

scholarly journals A new thelastomatid of the genus Blatticola Schwenk, 1926 (Nematoda, Thelastomatidae) a parasite of cricket (Orthoptera, Gryllidae) from Argentina

2009 ◽  
Vol 31 (73/75) ◽  
Author(s):  
Nora Beatriz Camino ◽  
Gastón Alejandro Schargorodsky
Keyword(s):  
New Species ◽  
Mouth Opening ◽  
Nerve Ring ◽  
The Body ◽  
Smooth Shell ◽  
Small Pore ◽  
Basal Bulb ◽  
Apical View

Blatticola biannulata n. sp. (Oxyurida, Thelastomatidae) a parasite of the cricket Anurogryllus muticus (De Geer)(Orthoptera, Gryllidae) from Argentina, is described and illustrated. This is the second species of the genusBlatticola found parasitizing cricket. Females of this new species is characterized by the cuticle that is annulatedfrom the anterior end up to the middle of the body, the mouth opening being subtriangular in shape surroundedby 8 cephalic papillae, the short stoma with two semicircles sclerotised and the telostoma with onemovable tooth, small pore shaped amphids, an oesophagus divided into three parts, anterior cylindrical corpus,isthmus distinct, and basal bulb valvated, the nerve ring situated arounded the isthmus, the intestine broadestanteriorly, eggs oval, smooth shell, in apical view show a triangular section, with three wings, the dorsal oneand two lateroventrals, males with one pair of preanal, and two pairs of postanal papillae, and the tail appendageshort, conical and pointed, the female has in the top an structure of anchorage, like structure of grasp.

Utriculimermis microcaudata n. gen., n. sp., a new genus and species of Mermithidae (Nematoda) of the rivers Lafnitz and Teigitsch in the southeastern Austrian Alps

Nematology ◽  
2001 ◽  
Vol 3 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Peter Deixelberger ◽  
Helmut Kaiser
Keyword(s):  
Body Length ◽  
Excretory Pore ◽  
Light Microscope ◽  
New Genus ◽  
Mouth Opening ◽  
Nerve Ring ◽  
The Body ◽  
Running Waters ◽  
New Genus And Species ◽  
Austrian Alps

AbstractUtriculimermis microcaudata n. gen., n. sp. (Nematoda: Mermithidae) is described from the hyporheic biotope of two running waters in southeastern Austria. The mermithids were sampled by pumping and with a modified 'Hess'-sampler. The characteristics of this new genus are: long body length, a very long pharynx which attains about 95% of the body length, six head papillae, mouth opening terminal, six hypodermal chords at midbody level, excretory pore present near the nerve ring, small cupshaped amphids, cuticula lacking cross fibres under light microscope, males with long slightly curved spiculum, very large number of genital papillae, vulva slightly curved to barrel-shaped with vulval flap, postparasitic juveniles with very short tail appendage often only present as a button-like nipple.

Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

1978 ◽  
Vol 36 (2) ◽  
pp. 600-601
Author(s):  
Wiktor Djaczenko ◽  
Carmen Calenda Cimmino
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Early Period ◽  
Postembryonic Development ◽  
Ruthenium Red ◽  
The Body ◽  
Tubifex Tubifex ◽  
Growth Stages ◽  
Cell Processes ◽  
Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

Characteristics of the dynamics of the central nervous system and att ention function in workers of shoe production

2020 ◽  
pp. 64-68
Author(s):  
F. L. Azizova ◽  
U. A. Boltaboev
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Women Workers ◽  
Functional State ◽  
The Body ◽  
Conflict Of Interests ◽  
Professional Groups ◽  
Universal Device ◽  
The Central Nervous System ◽  
Working Day

The features of production factors established at the main workplaces of shoe production are considered. The materials on the results of the study of the functional state of the central nervous system of women workers of shoe production in the dynamics of the working day are presented. The level of functional state of the central nervous system was determined by the speed of visual and auditory-motor reactions, installed using the universal device chronoreflexometer. It was revealed that in the body of workers of shoe production there is an early development of inhibitory processes in the central nervous system, which is expressed in an increase in the number of errors when performing tasks on proofreading tables. It was found that the most pronounced shift s in auditory-motor responses were observed in professional groups, where higher levels of noise were registered in the workplace. The correlation analysis showed a close direct relationship between the growth of mistakes made in the market and the decrease in production. An increase in the time spent on the task indicates the occurrence and growth of production fatigue.Funding. The study had no funding.Conflict of interests. The authors declare no conflict of interests.

Neurophysiological and morphological effects in the post-exposure vibration period during experimental modeling

2019 ◽  
pp. 284-290
Author(s):  
Natalya L. Yakimova ◽  
Vladimir A. Pankov ◽  
Aleksandr V. Lizarev ◽  
Viktor S. Rukavishnikov ◽  
Marina V. Kuleshova ◽  
...  
Keyword(s):  
Nervous System ◽  
Evoked Potentials ◽  
Experimental Model ◽  
Visual Evoked Potentials ◽  
The Body ◽  
Behavioral Activity ◽  
Contact Period ◽  
Vibration Exposure ◽  
Visual Evoked

Introduction. Vibration disease continues to occupy one of the leading places in the structure of professional pathology. In workers after the termination of contact with vibration generalization and progression of violations in an organism is noted. The pathogenetic mechanisms of the progredient course of disturbances in the nervous system in the post-contact period of vibration exposure remain insufficiently studied.The aim of the study was to test an experimental model of vibration exposure to assess the neurophysiological and morphological effects of vibration in rats in the dynamics of the post-contact period.Materials and methods. The work was performed on 168 white male outbred rats aged 3 months weighing 180–260 g. The vibration effect was carried out on a 40 Hz vibrating table for 60 days 5 times a week for 4 hours a day. Examination of animals was performed after the end of the physical factor, on the 30th, 60th and 120th day of the post-contact period. To assess the long-term neurophysiological and morphofunctional effects of vibration in rats, we used indicators of behavioral reactions, bioelectric activity of the somatosensory zone of the cerebral cortex, somatosensory and visual evoked potentials, parameters of muscle response, morphological parameters of nervous tissue.Results. In the dynamics of the post-contact period observed the preservation of violations of tentatively research, motor and emotional components of behavior. In the Central nervous system instability of activity of rhythms of an electroencephalogram, decrease in amplitude of visual evoked potentials, lengthening of latency of somatosensory evoked potentials, decrease in total number of normal neurons and astroglia is established. In the peripheral nervous system remained changes in indicators: increasing duration and latency, reducing the amplitude of the neuromuscular response.Conclusions: The experimental model allows us to study the long-term neurophysiological and morphological effects of vibration on the body. The formation and preservation of changes in behavioral activity, neurophysiological and morphological effects of vibration from the 30th to the 120th day of the post-contact period were confirmed.

Emotional processing and the autonomic nervous system: a comprehensive meta-analytic investigation

2018 ◽  
Author(s):  
Pedro Silva Moreira ◽  
Pedro Chaves ◽  
Nuno Dias ◽  
Patrício Costa ◽  
Pedro Rocha Almeida
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Skin Conductance ◽  
Emotional Processing ◽  
Skin Conductance Level ◽  
The Body ◽  
Analytic Investigation ◽  
Physiological Basis ◽  
Autonomic Nervous ◽  
Conductance Level

Background: The search for autonomic correlates of emotional processing has been a matter of interest for the scientific community with the goal of identifying the physiological basis of emotion. Despite an extensive state-of-the-art exploring the correlates of emotion, there is no absolute consensus regarding how the body processes an affective state.Objectives: In this work, we aimed to aggregate the literature of psychophysiological studies in the context of emotional induction. Methods: For this purpose, we conducted a systematic review of the literature and a meta-analytic investigation, comparing different measures from the electrodermal, cardiovascular, respiratory and facial systems across emotional categories/dimensions. Two-hundred and ninety-one studies met the inclusion criteria and were quantitatively pooled in random-effects meta-analytic modelling. Results: Heart rate and skin conductance level were the most reported psychophysiological measures. Overall, there was a negligible differentiation between emotional categories with respect to the pooled estimates. Of note, considerable amount of between-studies’ heterogeneity was found in the meta-analytic aggregation. Self-reported ratings of emotional arousal were found to be associated with specific autonomic-nervous system (ANS) indices, particularly with the variation of the skin conductance level. Conclusions: Despite this clear association, there is still a considerable amount of unexplained variability that raises the need for more fine-grained analysis to be implemented in future research in this field.

Sign in / Sign up

Export Citation Format

Share Document