Confocal light microscopy and electrophysiology of neurons in culture

Cell volume changes and regulation are thought to be important in the physiology and pathology of neurons. Osmotic challenges alter a number of physiologic parameters including electrical properties, chemosensitivity, and Na pump activity. Thus, a good method for correlating images of the living cell's surface with electrophysiologic measures is needed, and we are exploring the use of confocal light microscopy for imaging neurons in culture.Isolated neurons from ganglia of Aplvsia California were plated on polylysine coated coverslips in L15 media with 20% hemolymph at room temperature. Cells stained with “Dil” were imaged with a Bio—Rad MRC—600 and an Olympus BH—2. Images were displayed using Bio—Rad's maximum projection procedure, or Vital Images’ Voxel View software run on an IBM RISC 6000 Powerstation 320. Electrophysiologic properties were assessed after imaging.

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Plasma Membrane Water Permeability of Cultured Cells and Epithelia Measured by Light Microscopy with Spatial Filtering

The Journal of General Physiology ◽

10.1085/jgp.110.3.283 ◽

1997 ◽

Vol 110 (3) ◽

pp. 283-296 ◽

Cited By ~ 77

Author(s):

Javier Farinas ◽

Malea Kneen ◽

Megan Moore ◽

A.S. Verkman

Keyword(s):

Light Microscopy ◽

Cell Volume ◽

Water Permeability ◽

Signal Intensity ◽

Spatial Filtering ◽

Water Channels ◽

Molecular Water ◽

Toad Urinary Bladder ◽

Volume Changes ◽

Cell Layers

A method was developed to measure the osmotic water permeability (Pf) of plasma membranes in cell layers and applied to cells and epithelia expressing molecular water channels. It was found that the integrated intensity of monochromatic light in a phase contrast or dark field microscope was dependent on relative cell volume. For cells of different size and shape (Sf9, MDCK, CHO, A549, tracheal epithelia, BHK), increased cell volume was associated with decreased signal intensity; generally the signal decreased 10–20% for a twofold increase in cell volume. A theory relating signal intensity to relative cell volume was developed based on spatial filtering and changes in optical path length associated with cell volume changes. Theory predictions were confirmed by signal measurements of cell layers bathed in solutions of various osmolarities and refractive indices. The excellent signal-to-noise ratio of the transmitted light detection permitted measurement of cell volume changes of <1%. The method was applied to characterize transfected cells and tissues that natively express water channels. Pf in control Chinese hamster ovary cells was low (0.0012 cm/s at 23°C) and increased more than fourfold upon stable transfection with aquaporins 1, 2, 4, or 5. Pf in apical and basolateral membranes in polarized epithelial cells grown on porous supports was measured. Pfbl and Pfap were 0.0011 and 0.0024 cm/s (MDCK cells), and 0.0039 and 0.0052 cm/s (human tracheal cells) at 23°C. In intact toad urinary bladder, basolateral Pf was 0.036 cm/s and apical membrane Pf after vasopressin stimulation was 0.025 cm/s at 23°C. The results establish light microscopy with spatial filtering as a technically simple and quantitative method to measure water permeability in cell layers and provide the first measurement of the apical and basolateral membrane permeabilities of several important epithelial cell types.

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Na-pump activity in rat kidney cortex cells and its relationship with the cell volume

FEBS Letters ◽

10.1016/0014-5793(88)80046-2 ◽

1988 ◽

Vol 236 (2) ◽

pp. 318-320 ◽

Cited By ~ 5

Author(s):

Fulgencio Proverbio ◽

Teresa Proverbio ◽

Rosalía G. Matteo ◽

Trina M. Perrone ◽

Reinaldo Marín

Keyword(s):

Cell Volume ◽

Rat Kidney ◽

Kidney Cortex ◽

Rat Kidney Cortex ◽

Na Pump ◽

Pump Activity

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SEM Observations on the Germination of Euonymous Americanus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119363 ◽

1985 ◽

Vol 43 ◽

pp. 508-509

Author(s):

D.R. Hill ◽

J.R. McCurry ◽

L.P. Elliott ◽

G. Howard

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Light Microscopy ◽

Filter Paper ◽

Room Temperature ◽

Food Source ◽

Environmental Chamber ◽

Dormant Stage ◽

Scanning Electron

Germination of Euonymous americanus in the laboratory has previously been unsuccessful. Ability to germinate Euonymous americanus. commonly known as the american strawberry bush, is important in that it represents a valuable food source for the white-tailed deer. Utilizing the knowledge that its seeds spend a period of time in the rumin fluid of deer during their dormant stage, we were successful in initiating germination. After a three month drying period, the seeds were placed in 25 ml of buffered rumin fluid, pH 8 at 40°C for 48 hrs anaerobically. They were then allowed to dry at room temperature for 24 hrs, placed on moistened filter paper and enclosed within an environmental chamber. Approximately four weeks later germination was detected and verified by scanning electron microscopy; light microscopy provided inadequate resolution. An important point to note in this procedure is that scarification, which was thought to be vital for germination, proved to be unnecessary for successful germination to occur. It is believed that germination was propagated by the secretion of enzymes or prescence of acids produced by microorganisms found in the rumin fluid since sterilized rumin failed to bring about germination.

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Cytoplasmic K+ effects on phosphoenzyme of Na,K-ATPase proteoliposomes and on the Na+-pump activity.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)81518-1 ◽

1988 ◽

Vol 263 (21) ◽

pp. 10320-10325

Author(s):

A Yoda ◽

S Yoda

Keyword(s):

Na Pump ◽

Pump Activity

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Redox-Inactive CO2 Determines Atmospheric Stability of Electrical Properties of ZnO Nanowire Devices through a Room-Temperature Surface Reaction

ACS Applied Materials & Interfaces ◽

10.1021/acsami.9b13231 ◽

2019 ◽

Vol 11 (43) ◽

pp. 40260-40266

Author(s):

Kentaro Nakamura ◽

Tsunaki Takahashi ◽

Takuro Hosomi ◽

Takehito Seki ◽

Masaki Kanai ◽

...

Keyword(s):

Electrical Properties ◽

Room Temperature ◽

Surface Reaction ◽

Atmospheric Stability ◽

Zno Nanowire ◽

Temperature Surface

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Liver cell hydration and integrin signaling

Biological Chemistry ◽

10.1515/hsz-2021-0193 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Michele Bonus ◽

Dieter Häussinger ◽

Holger Gohlke

Keyword(s):

Cell Volume ◽

Liver Cell ◽

Cell Function ◽

The Other ◽

Signaling Cascades ◽

Integrin Signaling ◽

Volume Changes ◽

The One ◽

And Oxidative Stress

Abstract Liver cell hydration (cell volume) is dynamic and can change within minutes under the influence of hormones, nutrients, and oxidative stress. Such volume changes were identified as a novel and important modulator of cell function. It provides an early example for the interaction between a physical parameter (cell volume) on the one hand and metabolism, transport, and gene expression on the other. Such events involve mechanotransduction (osmosensing) which triggers signaling cascades towards liver function (osmosignaling). This article reviews our own work on this topic with emphasis on the role of β1 integrins as (osmo-)mechanosensors in the liver, but also on their role in bile acid signaling.

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