scholarly journals Conserved neural circuit structure across Drosophila larval development revealed by comparative connectomics

2017 ◽  
Author(s):  
Stephan Gerhard ◽  
Ingrid Andrade ◽  
Richard D. Fetter ◽  
Albert Cardona ◽  
Casey M. Schneider-Mizell
Keyword(s):  
Structural Changes ◽  
Neural Circuit ◽  
Postembryonic Development ◽  
Neuronal Morphology ◽  
The Body ◽  
Structural Adaptation ◽  
Circuit Structure ◽  
Section Electron ◽  
Structural Growth ◽  
Serial Section Electron Microscopy

AbstractThroughout an animal’s postembryonic development, neuronal circuits must maintain appropriate output even as the body grows. The contribution of structural adaptation — neuronal morphology and synaptic connectivity — to circuit development remains unclear. In a previous paper (Schneider-Mizell et al., 2016), we measured the detailed neuronal morphological structures subserving neuronal connectivity in Drosophila. Here, we examine how neuronal morphology and connectivity change across postembyronic development. Using new and existing serial section electron microscopy volumes, we reconstructed an identified nociceptive circuit in two larvae, one 1st instar and one 3rd instar. We found extremely consistent, topographically-arranged circuit structure. Five-fold increases in size of interneurons were associated with compensatory structural changes that maintained cell-type-specific synaptic input as a fraction of total inputs. An increase in number of synaptic contacts was accompanied with a disproportionate increase in the number of small dendritic terminal branches relative to other neuronal compartments. We propose that these precise patterns of structural growth act to conserve the computational function of a circuit, for example determining the location of a nociceptive stimulus.

scholarly journals Conserved neural circuit structure across Drosophila larval development revealed by comparative connectomics

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Stephan Gerhard ◽  
Ingrid Andrade ◽  
Richard D Fetter ◽  
Albert Cardona ◽  
Casey M Schneider-Mizell
Keyword(s):  
Neural Circuit ◽  
Postembryonic Development ◽  
Neuronal Morphology ◽  
Neuronal Structure ◽  
Larval Stages ◽  
Section Electron ◽  
Structural Growth ◽  
Serial Section Electron Microscopy ◽  
Dendritic Branches ◽  
Circuit Function

During postembryonic development, the nervous system must adapt to a growing body. How changes in neuronal structure and connectivity contribute to the maintenance of appropriate circuit function remains unclear. Previously , we measured the cellular neuroanatomy underlying synaptic connectivity in Drosophila (<xref ref-type="bibr" rid="bib44">Schneider-Mizell et al., 2016</xref>). Here, we examined how neuronal morphology and connectivity change between first instar and third instar larval stages using serial section electron microscopy. We reconstructed nociceptive circuits in a larva of each stage and found consistent topographically arranged connectivity between identified neurons. Five-fold increases in each size, number of terminal dendritic branches, and total number of synaptic inputs were accompanied by cell type-specific connectivity changes that preserved the fraction of total synaptic input associated with each pre-synaptic partner. We propose that precise patterns of structural growth act to conserve the computational function of a circuit, for example determining the location of a dangerous stimulus.

Servitisation through structural adaptation

2021 ◽  
Vol 31 (3) ◽  
pp. 468-490
Author(s):  
Saad Zighan ◽  
Ziad Alkalha ◽  
David Bamford ◽  
Iain Reid ◽  
Zu'bi M.F. Al-Zu'bi
Keyword(s):  
Service Provision ◽  
Design Theory ◽  
Structural Changes ◽  
Oil And Gas ◽  
Project Managers ◽  
The Body ◽  
Exploratory Research ◽  
Organisational Structure ◽  
Structural Adaptation ◽  
Content Type

PurposeThe purpose of this study is to investigate the structural changes needed for project-based organisations (PBOs) to synthesise their project operations and services following the servitisation strategy. It addresses the question of how PBOs should change their organisational structure fitting with service provision strategy.Design/methodology/approachThis study followed an exploratory research method using a single in-depth case with evidence collected from 51 project managers from five different industry sectors: construction, oil and gas, IT, logistics and health careFindingsCapitalising on organisational design theory, it has been found that successfully extending PBOs' outcomes into a system of both project output and extra services requires an adjustment of organisational structure that creates greater value for both companies and customers. This required adjustment has been divided into five main categories: (1) collaboration cross-project and customers; (2) flexible workflow, (3) decentralised decision-making, (4) wide span of control and (5) project governance. However, the findings indicate that success can only be ensured by particular mutually coordinated organisational designs with a suitable balance of products and servicesPractical implicationsThis study presents vital indicators to PBOs practitioners when deploying servitisation within their operational strategy by adjusting the organisation's design.Social implicationsServitisation could add both economic and social values for a diverse set of project stakeholders. However, the sustainability performance of servitisation in servitised project-based organisations is an outcome of reducing the discrepancy between project operation and service provision activities.Originality/valueThis study contributes to the body of knowledge and proposes a structural alteration process in PBOs to help align project operations and service provision activities. It explains how project-based organisations reconfigure their resources to provide services.

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.

HISTOLOGICAL CHANGES IN THE INTESTINES OF POULTRY DURING FODDER INTOXICATION

2020 ◽  
Author(s):  
E.P. Dolgov ◽  
◽  
A.A. Abramov ◽  
E.V. Kuzminova ◽  
E.V. Rogaleva ◽  
...  
Keyword(s):  
Body Weight ◽  
Histological Examination ◽  
Aflatoxin B1 ◽  
Structural Changes ◽  
Clinical Manifestations ◽  
Feed Additives ◽  
The Body ◽  
Histological Changes ◽  
Beet Pulp

The article presents the data on the study of the influence of mycotoxins combination (T-2 toxin at the concentration of 0.095 mg/kg and aflatoxin B1 in the concentration of 0.019 mg/kg) on the body of quails and the results of pharmacocorrection of toxicosis with a complex consisting of beet pulp and lecithin. Structural changes in the intestines of quais at fodder mycotoxicosis are described. The use of antitoxic feed additives in poultry led to a weakening of the action of xenobiotics, which was confirmed by an increase in the safety of poultry and increase in body weight of quails, a decrease in the clinical manifestations of intoxication, as well as in positive changes in the structure of the intestine of the poultry during histological examination.

Influence of Ascorbic Acid on the Structure and Function of Alpha-2- macroglobulin: Investigations using Spectroscopic and Thermodynamic Techniques

2020 ◽  
Vol 27 (3) ◽  
pp. 201-209
Author(s):  
Syed Saqib Ali ◽  
Mohammad Khalid Zia ◽  
Tooba Siddiqui ◽  
Haseeb Ahsan ◽  
Fahim Halim Khan
Keyword(s):  
Ascorbic Acid ◽  
Conformational Changes ◽  
Structural Changes ◽  
The Body ◽  
Titration Calorimetry ◽  
Spectroscopic Techniques ◽  
Human Beings ◽  
Plasma Ascorbic Acid ◽  
Dietary Antioxidant ◽  
And Function

Background: Ascorbic acid is a classic dietary antioxidant which plays an important role in the body of human beings. It is commonly found in various foods as well as taken as dietary supplement. Objective: The plasma ascorbic acid concentration may range from low, as in chronic or acute oxidative stress to high if delivered intravenously during cancer treatment. Sheep alpha-2- macroglobulin (α2M), a human α2M homologue is a large tetrameric glycoprotein of 630 kDa with antiproteinase activity, found in sheep’s blood. Methods: In the present study, the interaction of ascorbic acid with alpha-2-macroglobulin was explored in the presence of visible light by utilizing various spectroscopic techniques and isothermal titration calorimetry (ITC). Results: UV-vis and fluorescence spectroscopy suggests the formation of a complex between ascorbic acid and α2M apparent by increased absorbance and decreased fluorescence. Secondary structural changes in the α2M were investigated by CD and FT-IR spectroscopy. Our findings suggest the induction of subtle conformational changes in α2M induced by ascorbic acid. Thermodynamics signatures of ascorbic acid and α2M interaction indicate that the binding is an enthalpy-driven process. Conclusion: It is possible that ascorbic acid binds and compromises antiproteinase activity of α2M by inducing changes in the secondary structure of the protein.

scholarly journals Syringeal vocal folds do not have a voice in zebra finch vocal development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alyssa Maxwell ◽  
Iris Adam ◽  
Pernille S. Larsen ◽  
Peter G. Sørensen ◽  
Coen P. H. Elemans
Keyword(s):  
Zebra Finch ◽  
Neural Circuit ◽  
Vocal Folds ◽  
Pressure Control ◽  
The Body ◽  
Vocal Development ◽  
Postnatal Maturation ◽  
Song System ◽  
Property Changes

AbstractVocal behavior can be dramatically changed by both neural circuit development and postnatal maturation of the body. During song learning in songbirds, both the song system and syringeal muscles are functionally changing, but it is unknown if maturation of sound generators within the syrinx contributes to vocal development. Here we densely sample the respiratory pressure control space of the zebra finch syrinx in vitro. We show that the syrinx produces sound very efficiently and that key acoustic parameters, minimal fundamental frequency, entropy and source level, do not change over development in both sexes. Thus, our data suggest that the observed acoustic changes in vocal development must be attributed to changes in the motor control pathway, from song system circuitry to muscle force, and not by material property changes in the avian analog of the vocal folds. We propose that in songbirds, muscle use and training driven by the sexually dimorphic song system are the crucial drivers that lead to sexual dimorphism of the syringeal skeleton and musculature. The size and properties of the instrument are thus not changing, while its player is.

Normal Synaptonemal Complex and Abnormal Recombination Nodules in Two Alleles of the Drosophila Meiotic Mutant mei-W68

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1337-1356 ◽  
Author(s):  
Adelaide T C Carpenter
Keyword(s):  
Electron Microscopy ◽  
Synaptonemal Complex ◽  
High Frequency ◽  
Serial Section ◽  
The Other ◽  
Wild Type ◽  
Recombination Nodules ◽  
Section Electron ◽  
Serial Section Electron Microscopy ◽  
Section Electron Microscopy

Abstract The meiotic phenotypes of two mutant alleles of the mei-W68 gene, 1 and L1, were studied by genetics and by serial-section electron microscopy. Despite no or reduced exchange, both mutant alleles have normal synaptonemal complex. However, neither has any early recombination nodules; instead, both exhibit high numbers of very long (up to 2 μm) structures here named “noodles.” These are hypothesized to be formed by the unchecked extension of identical but much shorter structures ephemerally seen in wild type, which may be precursors of early recombination nodules. Although the mei-W68L1 allele is identical to the mei-W681 allele in both the absence of early recombination nodules and a high frequency of noodles (i.e., it is amorphic for the noodle phene), it is hypomorphic in its effects on exchange and late recombination nodules. The differential effects of this allele on early and late recombination nodules are consistent with the hypothesis that Drosophila females have two separate recombination pathways—one for simple gene conversion, the other for exchange.

scholarly journals PPARs as Metabolic Sensors and Therapeutic Targets in Liver Diseases

2021 ◽  
Vol 22 (15) ◽  
pp. 8298
Author(s):  
Hugo Christian Monroy-Ramirez ◽  
Marina Galicia-Moreno ◽  
Ana Sandoval-Rodriguez ◽  
Alejandra Meza-Rios ◽  
Arturo Santos ◽  
...  
Keyword(s):  
Liver Diseases ◽  
Metabolic Regulation ◽  
Structural Changes ◽  
Critical Role ◽  
The Body ◽  
Molecular Characteristics ◽  
Signal Pathways ◽  
Virus Infections ◽  
Physiological Processes ◽  
Hepatic Level

Carbohydrates and lipids are two components of the diet that provide the necessary energy to carry out various physiological processes to help maintain homeostasis in the body. However, when the metabolism of both biomolecules is altered, development of various liver diseases takes place; such as metabolic-associated fatty liver diseases (MAFLD), hepatitis B and C virus infections, alcoholic liver disease (ALD), and in more severe cases, hepatocelular carcinoma (HCC). On the other hand, PPARs are a family of ligand-dependent transcription factors with an important role in the regulation of metabolic processes to hepatic level as well as in other organs. After interaction with specific ligands, PPARs are translocated to the nucleus, undergoing structural changes to regulate gene transcription involved in lipid metabolism, adipogenesis, inflammation and metabolic homeostasis. This review aims to provide updated data about PPARs’ critical role in liver metabolic regulation, and their involvement triggering the genesis of several liver diseases. Information is provided about their molecular characteristics, cell signal pathways, and the main pharmacological therapies that modulate their function, currently engaged in the clinic scenario, or in pharmacological development.

Staphylococcal infection and pathomurfological characteristic of the pituitary-adrenal-thyroid system

2020 ◽  
Vol 03 (04) ◽  
pp. 69-73
Author(s):  
Samira Mammadhasan Yagubova ◽  
◽  
Elchin Chingiz Akbarov ◽  
Tarana Nadir Mirzayeva ◽  
◽  
...  
Keyword(s):  
Structural Changes ◽  
Adrenal Glands ◽  
Early Stage ◽  
Morphological Changes ◽  
Endocrine System ◽  
Staphylococcal Infection ◽  
The Body ◽  
Glandular Cells ◽  
Exogenous Factors ◽  
Specific Symptoms

During the staphylococcal infection, changes in the interaction of glandular cells, dystrophic and disorganizing pathologies in tissues, especially acute structural and hemodynamic changes in the stroma of the glands in the pituitary-adrenal-thyroid system, develop from the first day of the experiment. At the end of the experiment, on the background of a decrease in exudative processes, fibroplastic reactions are significantly activated, resulting in signs of incomplete regeneration – mainly sclerotic processes and cystic-atrophic changes in the parenchyma. Structural changes in tissues in the early stages of staphylococcal infection and the dynamics of development are characterized by specific symptoms in each of the glands. Since the pituitary gland is exposed to endogenous and exogenous factors earlier and more often than the adrenal glands, and the adrenal glands are earlier than the thyroid gland, dystrophic and destructive changes in the pituitary and adrenal glands are more pronounced at the early stage of the experiment. These morphological changes can change the hormonal status of the body and lead to dysfunction of the endocrine system as a whole – a decrease in the functional activity of the glands to some extent, and even inhibition of adenohypophyseal cells. Key words: staphylococcal infection, peritonitis, pituitary, adrenal and thyroid glands

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