{{short description|Electrode used in electrophysiology}} {{About|the use of microelectrodes in electrophysiology|applications in electroanalytical chemistry|Ultramicroelectrode}} A '''microelectrode''' is an electrode used in electrophysiology either for recording neural signals or for the electrical stimulation of nervous tissue.<ref>{{Cite journal |last=Kita |first=Justin M |last2=Wightman |first2=R Mark |date=October 2008 |title=Microelectrodes for studying neurobiology |url=https://linkinghub.elsevier.com/retrieve/pii/S1367593108001130 |journal=Current Opinion in Chemical Biology |language=en |volume=12 |issue=5 |pages=491–496 |doi=10.1016/j.cbpa.2008.06.035 |pmc=2642896 |pmid=18675377}}</ref><ref>{{Citation |title=Electroanalytical techniques in biosciences: conductometry, coulometry, voltammetry, and electrochemical sensors |date=2022-01-01 |work=Analytical Techniques in Biosciences |pages=157–178 |url=https://www.sciencedirect.com/science/chapter/edited-volume/abs/pii/B978012822654400004X |access-date=2026-03-13 |publisher=Academic Press |language=en-US |doi=10.1016/B978-0-12-822654-4.00004-X|url-access=subscription }}</ref> They were first developed by Ida Hyde in 1921.<ref name="Johnson">{{cite journal|last=Johnson|first=Elsie|year=1981|title=Ida Henrietta Hyde: Early Experiments|journal=Physiologist|volume=24|issue=6|pages=1–2|url=http://the-aps.org/publications/tphys/legacy/1981/issue6/10.pdf|access-date=2009-04-26|archive-url=https://web.archive.org/web/20110523180621/http://the-aps.org/publications/tphys/legacy/1981/issue6/10.pdf|archive-date=2011-05-23|url-status=dead|pmid=7043502}}</ref> Pulled glass pipettes with tip diameters of 0.5 μm or less are usually filled with 3 molars potassium chloride solution as the electrical conductor. When the tip penetrates a cell membrane the lipids in the membrane seal onto the glass, providing an excellent electrical connection between the tip and the interior of the cell, which is apparent because the microelectrode becomes electrically negative compared to the extracellular solution. There are also microelectrodes made with insulated metal wires, made from inert metals with high Young modulus such as tungsten, stainless steel, or platinum-iridium alloy<ref >{{cite journal |last=Cogan |first=Stuart F. |title=Neural Stimulation and Recording Electrodes|journal=Annual Review of Biomedical Engineering |date=August 2008 |volume=10 |issue=1 |pages=275–309 |doi=10.1146/annurev.bioeng.10.061807.160518 |pmid=18429704 |s2cid=25087051 |url=http://pdfs.semanticscholar.org/2184/efac2c7e8a1ae37b67780c851c4bf4c17c99.pdf |archive-url=https://web.archive.org/web/20190220094758/http://pdfs.semanticscholar.org/2184/efac2c7e8a1ae37b67780c851c4bf4c17c99.pdf |url-status=dead |archive-date=2019-02-20 }}</ref> and coated with glass or polymer insulator with exposed conductive tips. These are mostly used for recording from the external side of the cell membrane.
==See also== * Single-unit recording * Microelectrode array
== References == {{Reflist}}
Category:Neurophysiology Category:Physiology Category:Electrophysiology Category:Laboratory techniques