The characterization of presynaptic octopamine receptors modulating octopamine release from an identified neurone in the locust

1998 ◽  
Vol 201 (13) ◽  
pp. 2053-2060 ◽  
Author(s):  
KM Howell ◽  
PD Evans
Keyword(s):  
Central Nervous System ◽  
Rank Order ◽  
Muscle Preparation ◽  
Pharmacological Profile ◽  
Octopamine Receptors ◽  
High K ◽  
Wide Range ◽  
Octopamine Receptor ◽  
Dorsal Unpaired Median

Octopamine release has been demonstrated from the dorsal unpaired median neurone to the locust extensor-tibiae muscle (DUMETi) in response to high-[K+] saline. Here, we provide evidence for the existence of presynaptic inhibitory autoreceptors for octopamine on the DUMETi terminals and report on their pharmacological profile. Octopamine release was initiated by exposure to high-[K+] saline (0. 1 mol l-1) and measured using a radioenzyme assay for octopamine. Octopamine receptor antagonists (10(-4 )mol l-1) potentiated the high-[K+]-mediated release of octopamine with the following rank order of potency: phentolamine = metoclopramide > mianserin = chlorpromazine > cyproheptadine > yohimbine. Octopamine receptor agonists (10(-4 )mol l-1) inhibited the high-[K+]-mediated release of octopamine with the following rank order of potency: naphazoline > tolazoline > clonidine. Thus, the octopamine autoreceptors on the DUMETi terminals are much closer pharmacologically to the pre-and postsynaptic OCTOPAMINE2 receptors in the locust extensor-tibiae muscle preparation than to the OCTOPAMINE3 receptors from the locust central nervous system. The results suggest that there is likely to be more than one type of insect neuronal octopamine receptor. It is also likely that presynaptic modulation of octopamine release may be confined to octopamine receptors since a wide range of other putative modulatory substances did not produce this effect.

scholarly journals AmOctα2R: Functional Characterization of a Honeybee Octopamine Receptor Inhibiting Adenylyl Cyclase Activity

2020 ◽  
Vol 21 (24) ◽  
pp. 9334
Author(s):  
Wolfgang Blenau ◽  
Joana Alessandra Wilms ◽  
Sabine Balfanz ◽  
Arnd Baumann
Keyword(s):  
Biogenic Amines ◽  
Functional Characterization ◽  
Eukaryotic Cell ◽  
Intracellular Camp ◽  
Octopamine Receptors ◽  
Pharmacological Data ◽  
Large Protein Family ◽  
Octopamine Receptor ◽  
G Protein Coupled

The catecholamines norepinephrine and epinephrine are important regulators of vertebrate physiology. Insects such as honeybees do not synthesize these neuroactive substances. Instead, they use the phenolamines tyramine and octopamine for similar physiological functions. These biogenic amines activate specific members of the large protein family of G protein-coupled receptors (GPCRs). Based on molecular and pharmacological data, insect octopamine receptors were classified as either α- or β-adrenergic-like octopamine receptors. Currently, one α- and four β-receptors have been molecularly and pharmacologically characterized in the honeybee. Recently, an α2-adrenergic-like octopamine receptor was identified in Drosophila melanogaster (DmOctα2R). This receptor is activated by octopamine and other biogenic amines and causes a decrease in intracellular cAMP ([cAMP]i). Here, we show that the orthologous receptor of the honeybee (AmOctα2R), phylogenetically groups in a clade closely related to human α2-adrenergic receptors. When heterologously expressed in an eukaryotic cell line, AmOctα2R causes a decrease in [cAMP]i. The receptor displays a pronounced preference for octopamine over tyramine. In contrast to DmOctα2R, the honeybee receptor is not activated by serotonin. Its activity can be blocked efficiently by 5-carboxamidotryptamine and phentolamine. The functional characterization of AmOctα2R now adds a sixth member to this subfamily of monoaminergic receptors in the honeybee and is an important step towards understanding the actions of octopamine in honeybee behavior and physiology.

Pharmacological Characterization of an Adenylyl Cyclase-Coupled 5-HT Receptor in Aplysia: Comparison With Mammalian 5-HT Receptors

2003 ◽  
Vol 89 (3) ◽  
pp. 1440-1455 ◽  
Author(s):  
Jonathan E. Cohen ◽  
Chiadi U. Onyike ◽  
Virginia L. McElroy ◽  
Allison H. Lin ◽  
Thomas W. Abrams
Keyword(s):  
Adenylyl Cyclase ◽  
Rank Order ◽  
Physiological Saline ◽  
Receptor Subtypes ◽  
Pharmacological Profile ◽  
Pharmacological Characterization ◽  
Firing Properties ◽  
Stimulation Of

We attempted to identify compounds that are effective in blocking the serotonin (5-hydroxytryptamine, 5-HT) receptor(s) that activate adenylyl cyclase (AC) in Aplysia CNS. We call this class of receptor 5-HTapAC. Eight of the 14 antagonists tested were effective against 5-HTapAC in CNS membranes with the following rank order of potency: methiothepin > metergoline ∼ fluphenazine > clozapine > cyproheptadine ∼ risperidone ∼ ritanserin > NAN-190. GR-113808, olanzapine, Ro-04-6790, RS-102221, SB-204070, and spiperone were inactive. Methiothepin completely blocked 5-HT stimulation of AC with a K b of 18 nM. Comparison of the pharmacological profile of the 5-HTapAC receptor with those of mammalian 5-HT receptor subtypes suggested it most closely resembles the 5-HT6 receptor. AC stimulation in Aplysia sensory neuron (SN) membranes was also blocked by methiothepin. Methiothepin substantially inhibited two effects of 5-HT on SN firing properties that are mediated by a cAMP-dependent reduction in S-K+ current: spike broadening in tetraethylammonium/nifedipine and increased excitability. Consistent with cyproheptadine blocking 5-HT stimulation of AC, cyproheptadine also blocked the 5-HT-induced increase in SN excitability. Methiothepin was less effective in blocking AC-mediated modulatory effects of 5-HT in electrophysiological experiments on SNs than in blocking AC stimulation in CNS or SN membranes. This reduction in potency appears to be due to effects of the high ionic strength of physiological saline on the binding of this antagonist to the receptor. Methiothepin also antagonized AC-coupled dopamine receptors but not AC-coupled small cardioactive peptide receptors. In conjunction with other pharmacological probes, this antagonist should be useful in analyzing the role of 5-HT in various forms of neuromodulation in Aplysia.

DIAGNOSTIC VALUE OF SPECIFIC ANTIBODY SYNTHESIS IN BRAIN OF PATIENTS WITH NEUROINFECTIONS

2019 ◽  
Vol 72 (8) ◽  
pp. 1437-1441
Author(s):  
Pavel Dyachenko ◽  
Igor Filchakov ◽  
Anatoly Dyachenko ◽  
Victoria Kurhanskaya
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Clinical Manifestations ◽  
Diagnostic Value ◽  
Diagnostic Challenge ◽  
Specific Antibodies ◽  
Intrathecal Synthesis ◽  
Varicella Zoster ◽  
Mrz Reaction ◽  
Wide Range

Introduction: Viral encephalitis accounts for 40-70% of all cases worldwide, central nervous system infections pose a diagnostic challenge because clinical manifestations are not typically pathognomonic for specific pathogens, and a wide range of agents can be causative. The aim: To assess the diagnostic value of intrathecal synthesis of specific antibodies in patients with inflammatory lesions of the central nervous system. Materials and methods: Within the framework of the study, two groups of 90 people in each were formed from the patients with neuroinfections admitted to our Center. Intrathecal synthesis (ITS) of total (unspecific) IgG in members of one of group (group of compare) was determined. Brain synthesis of specific antibodies (Ab) to some neurotropic pathogens (herpes simplex virus 1/2, cytomegalovirus, Epstein-Barr virus, varicella zoster virus, rubella virus, Borrelies) was studied in the second group of patients (group of interest). There were no statistically significant differences between groups by gender and age. Encephalitis and encephalomyelitis prevailed among patients of both groups Results: ITS of total IgG was established in 30 (33.3 ± 6.1 %) patients of the first group with IgG index more than 0.6 indicating on inflammatory process in CNS and no marked changes of CSF. ITS of specific Ab was determined in 23 of 90 (25.6 ± 4.6 %) patients included into group of interest. In more than half of cases Ab to several infectious agents were detected simultaneously. ITS of various specificity, in particular, to measles and rubella viruses, and VZV, known as MRZ-reaction, is characteristic of some autoimmune lesions of CNS, multiple sclerosis first of all. In fact, further research of 5 patients with MRZ-reaction confirmed their autoimmune failure of CNS. Detection of ITS in the CSF samples didn’t depend on concentration of specific Ab in serum and CSF and wasn’t followed by HEB dysfunctions which were observed with the same frequency in patients with or without ITS (13.0 % and 13.6 % respectively). Conclusion: Specific Ab synthesis to several neurotropic pathogens in the CSF of significant part of examined patients was established. Thus, diagnostic value of ITS of specific immunoglobulins seems to be limited to cases in which autoimmune damage of the CNS is suspected.

Polymer Chemistry

2004 ◽  
Keyword(s):  
Conducting Polymers ◽  
Liquid Crystalline ◽  
Polymer Chemistry ◽  
Chain Growth ◽  
Crystalline Polymers ◽  
Wide Range ◽  
Cyclic Oligomers ◽  
Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

scholarly journals Organelle Genetics in Plants

2021 ◽  
Vol 22 (4) ◽  
pp. 2104
Author(s):  
Pedro Robles ◽  
Víctor Quesada
Keyword(s):  
Rna Editing ◽  
Posttranscriptional Regulation ◽  
Genome Engineering ◽  
Plant Mitochondria ◽  
Plastid Dna ◽  
Chloroplast Genomes ◽  
Wide Range ◽  
Organelle Genetics ◽  
Selection Of

Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled “Organelle Genetics in Plants.” This selection of papers covers a wide range of topics related to chloroplasts and plant mitochondria research: (i) organellar gene expression (OGE) and, more specifically, chloroplast RNA editing in soybean, mitochondria RNA editing, and intron splicing in soybean during nodulation, as well as the study of the roles of transcriptional and posttranscriptional regulation of OGE in plant adaptation to environmental stress; (ii) analysis of the nuclear integrants of mitochondrial DNA (NUMTs) or plastid DNA (NUPTs); (iii) sequencing and characterization of mitochondrial and chloroplast genomes; (iv) recent advances in plastid genome engineering. Here we summarize the main findings of these works, which represent the latest research on the genetics, genomics, and biotechnology of chloroplasts and mitochondria.

scholarly journals Molecular Modeling of Histamine Receptors—Recent Advances in Drug Discovery

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1778
Author(s):  
Pakhuri Mehta ◽  
Przemysław Miszta ◽  
Sławomir Filipek
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Molecular Modeling ◽  
Molecular Targets ◽  
Histamine Receptors ◽  
Experimental Characterization ◽  
Complex Disorders ◽  
Theoretical Investigations ◽  
Recent Developments

The recent developments of fast reliable docking, virtual screening and other algorithms gave rise to discovery of many novel ligands of histamine receptors that could be used for treatment of allergic inflammatory disorders, central nervous system pathologies, pain, cancer and obesity. Furthermore, the pharmacological profiles of ligands clearly indicate that these receptors may be considered as targets not only for selective but also for multi-target drugs that could be used for treatment of complex disorders such as Alzheimer’s disease. Therefore, analysis of protein-ligand recognition in the binding site of histamine receptors and also other molecular targets has become a valuable tool in drug design toolkit. This review covers the period 2014–2020 in the field of theoretical investigations of histamine receptors mostly based on molecular modeling as well as the experimental characterization of novel ligands of these receptors.

scholarly journals Immunological and Molecular Characterization of Goα-like Proteins in the Drosophila Central Nervous System

1989 ◽  
Vol 264 (31) ◽  
pp. 18552-18560 ◽  
Author(s):  
N C Thambi ◽  
F Quan ◽  
W J Wolfgang ◽  
A Spiegel ◽  
M Forte
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Molecular Characterization

scholarly journals Characterization of a Novel CaCO3-Forming Alkali-Tolerant Rhodococcus erythreus S26 as a Filling Agent for Repairing Concrete Cracks

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2967
Author(s):  
Seunghoon Choi ◽  
Sungjin Park ◽  
Minjoo Park ◽  
Yerin Kim ◽  
Kwang Min Lee ◽  
...  
Keyword(s):  
Building Materials ◽  
Culture Fluid ◽  
Natural Phenomenon ◽  
Environment Friendly ◽  
Wide Range ◽  
Filling Agent ◽  
Calcium Source ◽  
Alkali Tolerance ◽  
High Alkali

Biomineralization, a well-known natural phenomenon associated with various microbial species, is being studied to protect and strengthen building materials such as concrete. We characterized Rhodococcus erythreus S26, a novel urease-producing bacterium exhibiting CaCO3-forming activity, and investigated its ability in repairing concrete cracks for the development of environment-friendly sealants. Strain S26 grown in solid medium formed spherical and polygonal CaCO3 crystals. The S26 cells grown in a urea-containing liquid medium caused culture fluid alkalinization and increased CaCO3 levels, indicating that ureolysis was responsible for CaCO3 formation. Urease activity and CaCO3 formation increased with incubation time, reaching a maximum of 2054 U/min/mL and 3.83 g/L, respectively, at day four. The maximum CaCO3 formation was achieved when calcium lactate was used as the calcium source, followed by calcium gluconate. Although cell growth was observed after the induction period at pH 10.5, strain S26 could grow at a wide range of pH 4–10.5, showing its high alkali tolerance. FESEM showed rhombohedral crystals of 20–60 µm in size. EDX analysis indicated the presence of calcium, carbon, and oxygen in the crystals. XRD confirmed these crystals as CaCO3 containing calcite and vaterite. Furthermore, R. erythreus S26 successfully repaired the artificially induced large cracks of 0.4–0.6 mm width.

scholarly journals Isolation and Characterization of Strain Exiguobacterium sp. KRL4, a Producer of Bioactive Secondary Metabolites from a Tibetan Glacier

2021 ◽  
Vol 9 (5) ◽  
pp. 890
Author(s):  
Pietro Tedesco ◽  
Fortunato Palma Esposito ◽  
Antonio Masino ◽  
Giovanni Andrea Vitale ◽  
Emiliana Tortorella ◽  
...  
Keyword(s):  
Phenotypic Analysis ◽  
Biological Assays ◽  
C Elegans ◽  
Isolation And Characterization ◽  
Wide Range ◽  
Protein Encoding ◽  
Nematocidal Activity ◽  
Extremophilic Microorganisms ◽  
Unique Source

Extremophilic microorganisms represent a unique source of novel natural products. Among them, cold adapted bacteria and particularly alpine microorganisms are still underexplored. Here, we describe the isolation and characterization of a novel Gram-positive, aerobic rod-shaped alpine bacterium (KRL4), isolated from sediments from the Karuola glacier in Tibet, China. Complete phenotypic analysis was performed revealing the great adaptability of the strain to a wide range of temperatures (5–40 °C), pHs (5.5–8.5), and salinities (0–15% w/v NaCl). Genome sequencing identified KRL4 as a member of the placeholder genus Exiguobacterium_A and annotation revealed that only half of the protein-encoding genes (1522 of 3079) could be assigned a putative function. An analysis of the secondary metabolite clusters revealed the presence of two uncharacterized phytoene synthase containing pathways and a novel siderophore pathway. Biological assays confirmed that the strain produces molecules with antioxidant and siderophore activities. Furthermore, intracellular extracts showed nematocidal activity towards C. elegans, suggesting that strain KRL4 is a source of anthelmintic compounds.

scholarly journals Towards Reduced CNNs for De-Noising Phase Images Corrupted with Speckle Noise

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 255
Author(s):  
Marie Tahon ◽  
Silvio Montresor ◽  
Pascal Picart
Keyword(s):  
Phase Error ◽  
Speckle Noise ◽  
Experimental Conditions ◽  
Benchmark Data ◽  
Wide Range ◽  
Phase Images ◽  
Different Depths ◽  
Phase Data ◽  
Do So

Digital holography is a very efficient technique for 3D imaging and the characterization of changes at the surfaces of objects. However, during the process of holographic interferometry, the reconstructed phase images suffer from speckle noise. In this paper, de-noising is addressed with phase images corrupted with speckle noise. To do so, DnCNN residual networks with different depths were built and trained with various holographic noisy phase data. The possibility of using a network pre-trained on natural images with Gaussian noise is also investigated. All models are evaluated in terms of phase error with HOLODEEP benchmark data and with three unseen images corresponding to different experimental conditions. The best results are obtained using a network with only four convolutional blocks and trained with a wide range of noisy phase patterns.

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