Chronoamperometry in brain slices: Quantitative evaluations of in vivo electrochemistry

Hitchhiker’s Guide to Voltammetry: Acute and Chronic Electrodes for in Vivo Fast-Scan Cyclic Voltammetry

“…Slow potential sweeps between −0.2 to +0.6 V vs Ag/AgCl revealed peaks in current corresponding to the oxidation and reduction of electroactive substances; however, the identity of the molecule(s) producing the signal was unclear, with the authors suggesting it could arise from dopamine, norepinephrine, or ascorbic acid. Indeed, early voltammetric measurements suffered from poor chemical resolution between catecholamines and other easily oxidized species, often present in the brain at higher concentrations. − In response to these problems, criteria were developed to ensure that intended analytes were indeed the source of recorded signals, including electrochemical, anatomical, pharmacological, and independent verification. − A major advance to the field came with the development of fast-scan cyclic voltammetry (FSCV), a technique that utilizes rapid potential sweeps to oxidize and reduce analytes of interest. − This process produces cyclic voltammograms, which display measured current as a function of the applied potential, that serve as “fingerprints” for compound identification, providing an advantage over single potential techniques. − This moderate chemical selectivity allows the use of chemometric methods to separate, and subsequently quantitate, analytes with different current–potential characteristics (see Chemometric Data Analysis section below). , …”

Filtration disrupts synaptosomes during radiochemical analysis of serotonin uptake: Comparison with chronoamperometry in SERT knockout mice

“…This method has been utilized to measure uptake rates in different tissue preparations including brain synaptosomes (O'Reilly and Reith, 1988;Reith et al, 1989;Reith and O'Reilly, 1990;Hyde and Bennett, 1994;Fernandez et al, 2003;Ghijsen et al, 2003), cultured cells (Inazu et al, 2001;Fernandez et al, 2003) and brain slices (Reyes-Haro et al, 2003). Electrochemical methods including chronoamperometry, rotating disk electrode voltammetry and fast cyclic voltammetry have also been used to study transporter function with the added benefits of improved temporal resolution and in vivo applicability (Adams, 1976;Schenk et al, 1983;Gerhardt, 1995;Bunin et al, 1998;Daws et al, 1998;Earles and Schenk, 1998;Michael and Wightman, 1999;Troyer et al, 2002;Montanez et al, 2003).…”

Recent Advances in Biosensing for Neurotransmitters and Disease Biomarkers using Microelectrodes

“…Here, the limit of detection of 721 pM was observed to remain unchanged and only a modest 35 % decrease in sensitivity towards dopamine was observed . Considering that the extracellular concentration of dopamine in the brain is between 0.2–2 μM, a limit of detection lower than 0.2 μM is more suited for in vivo detection.…”