A Modified Coaxial Compound Micropipette for Extracellular Iontophoresis and Intracellular Recording: Fabrication, Performance and Theory.
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- Remmers John E.
- Respiratory Research Group, University of Calgary, Calgary
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- Schultz Stanley A.
- Respiratory Research Group, University of Calgary, Calgary
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- Wallace Jacqueline
- Respiratory Research Group, University of Calgary, Calgary
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- Takeda Ryuji
- Department of Pharmacology, Faculty of Medicine, Toyama Medical and Pharmaceutical University
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- Haji Akira
- Department of Pharmacology, Faculty of Medicine, Toyama Medical and Pharmaceutical University
Bibliographic Information
- Other Title
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- Modified Coaxial Compound Micropipette
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Abstract
Investigation of the identity and modes of action of neurotransmitters in the mammalian central nervous system can be facilitated by simultaneous intracellular recording of membrane potential and extracellular iontophoresis of agonists and antagonists. We describe here techniques for conveniently constructing a compound microelectrode, originally described by Sonnhof (Pflugers Arch 341, 351-358, 1973), suitable for such studies. The Sonnhof electrode consists of two components, a centraxial micropipette for recording membrane potential surrounded by a cylindrical array of 6 pipettes for iontophoresis. The cylindrical array tapers coaxially and terminates in 6 contiguous, crescent-shaped orifices surrounding the terminal portion of the central pipette, 25-50 μm from the tip. Pipettes were constructed from borosilicate glass tubing of 1-mm wall thickness having a 10-mm or 16-mm outer diameter. The resistances, flux and transport numbers for iontophoresis of glycine were measured for pipettes constructed from both sizes of glass. Flux increased with increasing levels of current, and transport number decreased with increasing micropipette resistance. A spherical diffusion model points out the steep dependence of steady state concentration on diffusional distance, stressing the importance of diminishing the distance between the iontophoresis source and the recording site. This is particularly true when brief pulses of current are used.
Journal
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- The Japanese Journal of Pharmacology
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The Japanese Journal of Pharmacology 75 (2), 161-169, 1997
The Japanese Pharmacological Society
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Details 詳細情報について
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- CRID
- 1390001204285277824
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- NII Article ID
- 10008189651
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- NII Book ID
- AA00691188
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- COI
- 1:CAS:528:DyaK2sXntVKmur0%3D
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- ISSN
- 13473506
- 00215198
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- NDL BIB ID
- 4326414
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- PubMed
- 9414031
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- Text Lang
- en
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- Data Source
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- JaLC
- NDL
- Crossref
- PubMed
- CiNii Articles
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- Abstract License Flag
- Disallowed