The effects of direct-current magnetic fields on turtle retinas in vitro

Science ◽  
1983 ◽  
Vol 220 (4598) ◽  
pp. 715-717 ◽  
Author(s):  
M. Raybourn
Keyword(s):  
Magnetic Fields ◽  
Direct Current

Mutagenic Potential of Direct Current Magnetic Fields.

1997 ◽  
Author(s):  
John W. Obringer ◽  
Tara E. Nolan ◽  
Brandon Horne ◽  
Brian Kelchner
Keyword(s):  
Magnetic Fields ◽  
Direct Current ◽  
Mutagenic Potential

scholarly journals Direct Current Stimulation Disrupts Endothelial Glycocalyx and Tight Junctions of the Blood-Brain Barrier in vitro

2021 ◽  
Vol 9 ◽  
Author(s):  
Yifan Xia ◽  
Yunfei Li ◽  
Wasem Khalid ◽  
Marom Bikson ◽  
Bingmei M. Fu
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Tight Junctions ◽  
Blood Brain Barrier ◽  
Direct Current ◽  
Endothelial Glycocalyx ◽  
Microvascular Endothelial Cells ◽  
Bbb Permeability

Transcranial direct current stimulation (tDCS) is a non-invasive physical therapy to treat many psychiatric disorders and to enhance memory and cognition in healthy individuals. Our recent studies showed that tDCS with the proper dosage and duration can transiently enhance the permeability (P) of the blood-brain barrier (BBB) in rat brain to various sized solutes. Based on the in vivo permeability data, a transport model for the paracellular pathway of the BBB also predicted that tDCS can transiently disrupt the endothelial glycocalyx (EG) and the tight junction between endothelial cells. To confirm these predictions and to investigate the structural mechanisms by which tDCS modulates P of the BBB, we directly quantified the EG and tight junctions of in vitro BBB models after DCS treatment. Human cerebral microvascular endothelial cells (hCMECs) and mouse brain microvascular endothelial cells (bEnd3) were cultured on the Transwell filter with 3 μm pores to generate in vitro BBBs. After confluence, 0.1–1 mA/cm2 DCS was applied for 5 and 10 min. TEER and P to dextran-70k of the in vitro BBB were measured, HS (heparan sulfate) and hyaluronic acid (HA) of EG was immuno-stained and quantified, as well as the tight junction ZO-1. We found disrupted EG and ZO-1 when P to dextran-70k was increased and TEER was decreased by the DCS. To further investigate the cellular signaling mechanism of DCS on the BBB permeability, we pretreated the in vitro BBB with a nitric oxide synthase (NOS) inhibitor, L-NMMA. L-NMMA diminished the effect of DCS on the BBB permeability by protecting the EG and reinforcing tight junctions. These in vitro results conform to the in vivo observations and confirm the model prediction that DCS can disrupt the EG and tight junction of the BBB. Nevertheless, the in vivo effects of DCS are transient which backup its safety in the clinical application. In conclusion, our current study directly elucidates the structural and signaling mechanisms by which DCS modulates the BBB permeability.

scholarly journals Electrical impedance measurement system to assess in-situ experiments on epithelia under ELF magnetic fields exposure

2021 ◽  
Vol 19 (3) ◽  
pp. 217-226
Author(s):  
G. Domínguez ◽  
E. Cardiel ◽  
J.L Reyes ◽  
E. Sánchez ◽  
P.R. Hernández
Keyword(s):  
Impedance Spectroscopy ◽  
Magnetic Fields ◽  
Cell Cultures ◽  
Electrical Impedance ◽  
Controlled Environment ◽  
Spectroscopy Technique ◽  
In Situ Experiments ◽  
Impedance Spectroscopy Technique

Purpose: The development of an electric impedance meter based on the impedance spectroscopy technique, for in vitro and in situ experimentation, with cellular epithelia submitted to extremely low frequency magnetic fields in a controlled environment. Unlike other reported systems, a strength of the one presented here is that it avoids the influence of external factors on the experiment. Materials and methods: The designed system employs the electrical impedance values obtained by the impedance spectroscopy technique to determine the parameters of the simple equivalent electrical model of a cellular monolayer. The Madin-Darby Canine Kidney (MDCK) cell cultures were used as subjects of study in the experimental protocol. Results: The validation was carried out by comparing the transepithelial electrical impedance data of the cell cultures obtained with the developed system and those of the Cellzscope® commercial system used as the standard. Non-significant differences were obtained. Conclusion: It was confirmed that the developed system provides reliable values of transepithelial electrical impedance to experiment with cell cultures and take advantage of the controlled environment to reduce the effects of experimental management.

Rotating Permanent Magnetic Fields Exposure System for In Vitro Study

2004 ◽  
Vol 14 (2) ◽  
pp. 1643-1646
Author(s):  
T. Song ◽  
Z. Wang ◽  
D. Zhao ◽  
Q. Zhu ◽  
X. Huo ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
In Vitro Study ◽  
Vitro Study ◽  
Exposure System

Insights into the behavioural responses of juvenile thornback ray Raja clavata to alternating and direct current magnetic fields

2021 ◽  
Author(s):  
Luana Albert ◽  
Frédéric Olivier ◽  
Aurélie Jolivet ◽  
Laurent Chauvaud ◽  
Sylvain Chauvaud
Keyword(s):  
Magnetic Fields ◽  
Direct Current ◽  
Behavioural Responses ◽  
Thornback Ray ◽  
Raja Clavata

Single-unit pH-sensitive double-barreled microelectrodes for extracellular use

1984 ◽  
Vol 57 (3) ◽  
pp. 907-912
Author(s):  
S. Javaheri ◽  
A. De Hemptinne ◽  
I. Leusen
Keyword(s):  
Direct Current ◽  
Single Unit ◽  
Extracellular Fluid ◽  
Ph Sensitive ◽  
Current Potential

The purpose of this study is to systematically describe the construction of pH-sensitive double-barreled microelectrodes for extracellular use. The most important advantages of these microelectrodes are as follows: the reference and the pH barrels are next to each other, and therefore the measured pH is not affected by asymmetric or slowly spreading direct current potential. The diameter of the tip of the microelectrodes is between 7 and 35 micron. These pH-sensitive microelectrodes are generally stable and Nernstian. They can be used repeatedly both in vivo and in vitro to measure tissue extracellular fluid pH. Some applications are described.

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