Membrane Potential and Behavior Proposal of a Model System

1975 ◽  
pp. 77-90
Author(s):  
Victor Kai-Hwa Chen
Keyword(s):  
Membrane Potential ◽  
Model System ◽  
And Behavior

scholarly journals A scalable culturing system for the marine annelid Platynereis dumerilii

2019 ◽  
Author(s):  
Emily Kuehn ◽  
Alexander W. Stockinger ◽  
Jerome Girard ◽  
Florian Raible ◽  
B. Duygu Özpolat
Keyword(s):  
Aquatic Organisms ◽  
Model System ◽  
Light Conditions ◽  
Cell Type ◽  
Culture Methods ◽  
Cell Lineages ◽  
Full Life Cycle ◽  
Platynereis Dumerilii ◽  
Culturing Conditions ◽  
And Behavior

ABSTRACTPlatynereis dumerilii is a marine segmented worm (annelid) with externally fertilized embryos and it can be cultured for the full life cycle in the laboratory. The accessibility of embryos and larvae combined with the breadth of the established molecular and functional techniques has made P. dumerilii an attractive model for studying development, cell lineages, cell type evolution, reproduction, regeneration, the nervous system, and behavior. Traditionally, these worms have been kept in rooms dedicated for their culture. This allows for the regulation of temperature and light cycles, which is critical to synchronizing sexual maturation. However, regulating the conditions of a whole room present limitations, especially if experiments require being able to change culturing conditions. Here we present scalable and flexible culture methods that provide ability to control the environmental conditions, and have a multi-purpose culture space. We provide a closed setup shelving design with proper light conditions necessary for P. dumerilii to mature. We also implemented a standardized method of feeding P. dumerilii cultures with powdered spirulina which relieves the ambiguity associated with using frozen spinach, and helps standardize nutrition conditions across experiments and across different labs. By using these methods, we were able to raise mature P. dumerilii, capable of spawning and producing viable embryos for experimentation and replenishing culture populations. These methods will allow for the further accessibility of P. dumerilii as a model system, and they can be adapted for other aquatic organisms.

scholarly journals Planarians: A Versatile and Powerful Model System for Molecular Studies of Regeneration, Adult Stem Cell Regulation, Aging, and Behavior

2008 ◽  
Vol 2008 (11) ◽  
pp. pdb.emo101-pdb.emo101 ◽  
Author(s):  
N. J. Oviedo ◽  
C. L. Nicolas ◽  
D. S. Adams ◽  
M. Levin
Keyword(s):  
Stem Cell ◽  
Adult Stem Cell ◽  
Model System ◽  
Cell Regulation ◽  
Stem Cell Regulation ◽  
Molecular Studies ◽  
And Behavior

Heat shock induces mini-Cajal bodies in the Xenopus germinal vesicle

2002 ◽  
Vol 115 (10) ◽  
pp. 2011-2020 ◽  
Author(s):  
Korie E. Handwerger ◽  
Zheng'an Wu ◽  
Christine Murphy ◽  
Joseph G. Gall
Keyword(s):  
Heat Shock ◽  
Germinal Vesicle ◽  
Model System ◽  
Cajal Body ◽  
Self Organization ◽  
Cajal Bodies ◽  
Oocyte Nucleus ◽  
Evolutionarily Conserved ◽  
And Behavior ◽  
Heat Shock Induction

Cajal bodies are evolutionarily conserved nuclear organelles that are believed to play a central role in assembly of RNA transcription and processing complexes. Although knowledge of Cajal body composition and behavior has greatly expanded in recent years, little is known about the molecules and mechanisms that lead to the formation of these organelles in the nucleus. The Xenopus oocyte nucleus or germinal vesicle is an excellent model system for the study of Cajal bodies, because it is easy to manipulate and it contains 50-100 Cajal bodies with diameters up to 10 μm. In this study we show that numerous mini-Cajal bodies (less than 2 μm in diameter) form in the germinal vesicle after oocytes recover from heat shock. The mechanism for heat shock induction of mini-Cajal bodies is independent of U7 snRNA and does not require transcription or import of newly translated proteins from the cytoplasm. We suggest that Cajal bodies originate by self-organization of preformed components, preferentially on the surface of B-snurposomes.

Developmental toxicity of trichloroethylene in zebrafish (Danio rerio)

2020 ◽  
Vol 22 (3) ◽  
pp. 728-739 ◽  
Author(s):  
Katharine A. Horzmann ◽  
Ana M. Portales ◽  
Kathryn G. Batcho ◽  
Jennifer L. Freeman
Keyword(s):  
Heart Rate ◽  
Danio Rerio ◽  
Developmental Toxicity ◽  
Model System ◽  
Embryonic Exposure ◽  
System P ◽  
And Behavior

Embryonic exposure to ecologically relevant concentrations of TCE disrupts development, morphology, heart rate, and behavior in the zebrafish (Danio rerio) model system.

Physiological Pharmacokinetic Models: Some Aspects of Theory, Practice and Potential

1988 ◽  
Vol 4 (2) ◽  
pp. 151-171 ◽  
Author(s):  
Richard W. D'souza ◽  
Harold Boxenbaum
Keyword(s):  
Circulatory System ◽  
Model System ◽  
Pharmacokinetic Models ◽  
Deep Insight ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Pharmacodynamic Response ◽  
Physiological Models ◽  
And Behavior ◽  
High Degree ◽  
Insight Into

Models are intellectual constructs that pattern selected relationships among the elements of one system to correspond in some way to elements of a second system. In pharmacokinetics, physiological models provide a clearly articulated, rational, explanatory basis for the integration of empirical data; they do this by partitioning the biological system into relevant components (tissues, organs, etc.) and linking them together through the circulatory system. Unlike conventional mammillary compartment models, there is a clear correspondence between model system elements and physiological entities. By virtue of their high degree of physical and biochemical relevance, these models can help provide deep insight into structure, function and mechanism. Pharmacokinetic (and potentially pharmacodynamic) response-time relationships can thus be understood in terms of interconnections and behavior of constituent subsystems. At their worst, these models provide stale or infertile views of reality and thus frustrate and alienate us with the triviality of their insights. At their best, they allow us to understand the accumulation of thought in pharmacokinetics and pharmacodynamics, and help with the integration of data and improvement of experimental design.

scholarly journals Cleavage of Mcd1 by Caspase-like Protease Esp1 Promotes Apoptosis in Budding Yeast

2008 ◽  
Vol 19 (5) ◽  
pp. 2127-2134 ◽  
Author(s):  
Hui Yang ◽  
Qun Ren ◽  
Zhaojie Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Death ◽  
Membrane Potential ◽  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Apoptotic Cell ◽  
Model System ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Dual Functions

Over the last decade, yeast has been used successfully as a model system for studying the molecular mechanism of apoptotic cell death. Here, we report that Mcd1, the yeast homology of human cohesin Rad21, plays an important role in hydrogen peroxide-induced apoptosis in yeast. On induction of cell death, Mcd1 is cleaved and the C-terminal fragment is translocated from nucleus into mitochondria, causing the decrease of mitochondrial membrane potential and the amplification of cell death in a cytochrome c-dependent manner. We further demonstrate that the caspase-like protease Esp1 has dual functions and that it is responsible for the cleavage of Mcd1 during the hydrogen peroxide-induced apoptosis. When apoptosis is induced, Esp1 is released from the anaphase inhibitor Pds1. The activated Esp1 acts as caspase-like protease for the cleavage of Mcd1, which enhances the cell death via its translocation from nucleus to mitochondria.

Friction Dynamics of Geckolike Materials

MRS Advances ◽  
2016 ◽  
Vol 1 (40) ◽  
pp. 2769-2775
Author(s):  
Jonathan B. Puthoff
Keyword(s):  
Potential Energy ◽  
Energy Landscape ◽  
Model System ◽  
Structural Effects ◽  
Frictional Sliding ◽  
Frictional Properties ◽  
Potential Energy Landscape ◽  
External Forces ◽  
And Behavior ◽  
Friction Dynamics

ABSTRACTThe interface between the adhesive toes of geckos and a substrate consists of an array of regularly sized, densely packed, and elastically coupled nanoscopic contacts. The velocity-dependent friction exhibited by this system hints at a convolution of various material and structural effects. We explore the dynamics of frictional sliding in these materials using models based on arrays of coupled masses driven by external forces that can become pinned and unpinned to a potential energy landscape. The model system is driven at normalized velocities spanning 6 orders of magnitude, and the output of this model captures both the low-V and high-V behavior of the actual gecko materials. We explore modifications to the essential model that incorporate features more representative of the structure and behavior of the natural gecko system. These results have implications in the design of materials with custom frictional properties.

scholarly journals Structural studies on cell wall biogenesis-I: A method to produce high-quality protoplasts from alga Micrasterias denticulata, an emerging model in plant biology

2021 ◽  
Author(s):  
M Selvaraj
Keyword(s):  
Cell Wall ◽  
Cell Biology ◽  
Model System ◽  
Plant Biology ◽  
Cell Wall Biogenesis ◽  
Unicellular Green Alga ◽  
Biological Studies ◽  
Micrasterias Denticulata ◽  
And Behavior ◽  
Protoplast Production

Micrasterias denticulate is a freshwater unicellular green alga emerging as a model system in plant cell biology. This is an algae that has been examined in the context of cell wall research from early 1970s. Protoplast production from such a model system is important for many downstream physiological and cell biological studies. The algae produce intact protoplast in a straight two-step protocol involving 5% mannitol, 2% cellulysin, 4mM calcium chloride under a temperature ramping strategy. The process of protoplast induction and behavior of protoplast was examined by light microscopy and reported in this study.

scholarly journals Motor control of Drosophila feeding behavior

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Olivia Schwarz ◽  
Ali Asgar Bohra ◽  
Xinyu Liu ◽  
Heinrich Reichert ◽  
Krishnaswamy VijayRaghavan ◽  
...  
Keyword(s):  
Motor Control ◽  
Model System ◽  
Body Parts ◽  
Central Command ◽  
Motor Action ◽  
Proboscis Extension ◽  
The Individual ◽  
Genetic Targeting ◽  
Artificial Activation ◽  
And Behavior

The precise coordination of body parts is essential for survival and behavior of higher organisms. While progress has been made towards the identification of central mechanisms coordinating limb movement, only limited knowledge exists regarding the generation and execution of sequential motor action patterns at the level of individual motoneurons. Here we use Drosophila proboscis extension as a model system for a reaching-like behavior. We first provide a neuroanatomical description of the motoneurons and muscles contributing to proboscis motion. Using genetic targeting in combination with artificial activation and silencing assays we identify the individual motoneurons controlling the five major sequential steps of proboscis extension and retraction. Activity-manipulations during naturally evoked proboscis extension show that orchestration of serial motoneuron activation does not rely on feed-forward mechanisms. Our data support a model in which central command circuits recruit individual motoneurons to generate task-specific proboscis extension sequences.

scholarly journals Direct estimate of 1:1 stoichiometry of K+-Cl−cotransport in rabbit erythrocytes

2001 ◽  
Vol 281 (3) ◽  
pp. C825-C832 ◽  
Author(s):  
Michael L. Jennings ◽  
Mark F. Adame
Keyword(s):  
Membrane Potential ◽  
Red Blood Cells ◽  
Okadaic Acid ◽  
Blood Cells ◽  
Model System ◽  
Disulfonic Acid ◽  
Calyculin A ◽  
Direct Measure ◽  
Direct Estimate ◽  
Exchange Flux

This work was undertaken to obtain a direct measure of the stoichiometry of Na+-independent K+-Cl−cotransport (KCC), with rabbit red blood cells as a model system. To determine whether86Rb+can be used quantitatively as a tracer for KCC,86Rb+and K+effluxes were measured in parallel after activation of KCC with N-ethylmaleimide (NEM). The rate constant for NEM-stimulated K+efflux into isosmotic NaCl was smaller than that for86Rb+by a factor of 0.68 ± 0.11 (SD, n = 5). This correction factor was used in all other experiments to calculate the K+efflux from the measured86Rb+efflux. To minimize interference from the anion exchanger, extracellular Cl−was replaced with SO[Formula: see text], and 4,4′-diisothiocyanothiocyanatodihydrostilbene-2,2′-disulfonic acid was present in the flux media. The membrane potential was clamped near 0 mV with the protonophore 2,4-dinitrophenol. The Cl−efflux at 25°C under these conditions is ∼100,000-fold smaller than the uninhibited Cl−/Cl−exchange flux and is stimulated ∼2-fold by NEM. The NEM-stimulated36Cl−flux is inhibited by okadaic acid and calyculin A, as expected for KCC. The ratio of the NEM-stimulated K+to Cl−efflux is 1.12 ± 0.26 (SD, n = 5). We conclude that K+-Cl−cotransport in rabbit red blood cells has a stoichiometry of 1:1.

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