Temporal Resolution in Electrochemical Imaging on Single PC12 Cells Using Amperometry and Voltammetry at Microelectrode Arrays

Abstract

Carbon-fiber-microelectrode arrays (MEAs) have been utilized to electrochemically image neurochemical secretion from individual pheochromocytoma (PC12) cells. Dopamine release events were electrochemically monitored from seven different locations on single PC12 cells using alternately constant-potential amperometry and fast-scan cyclic voltammetry (FSCV). Cyclic voltammetry, when compared to amperometry, can provide excellent chemical resolution; however, spatial and temporal resolution are both compromised. The spatial and temporal resolution of these two methods has been quantitatively compared, and the differences explained using models of molecular diffusion at the nanogap between the electrode and the cell. A numerical simulation of the molecular flux reveals that the diffusion of dopamine molecules and electrochemical reactions both play important roles in the temporal resolution of electrochemical imaging. The simulation also reveals that the diffusion and electrode potential cause the differences in signal crosstalk between electrodes when comparing amperometry and FSCV.

Electrochemical Analysis of Neurotransmitters

“…For single-cell measurements, carbon-disk MEAs have been fabricated from carbon fibers inserted into multibarrel glass and from the deposition of carbon through pyrolysis onto a fused assembly of quartz capillaries to form up to 7 and 15 electrodes, respectively (81, 82). Researchers have also employed various microfabrication approaches to create MEA devices with an increased electrode number for single-cell and cell-cluster applications (83–85).…”

The spontaneously hypertensive and Wistar Kyoto rat models of ADHD exhibit sub-regional differences in dopamine release and uptake in the striatum and nucleus accumbens

“…Because of this, specialized techniques have been developed to evaluate DA dynamics in addition to microdialysis. These include electrochemical techniques such as fast-scan cyclic voltammetry, constant potential amperometry, and high-speed chronoamperometry (Lee et al 2006; Littrell et al 2012; Park et al 2011; Zhang et al 2011). Fast-scan cyclic voltammetry allows for high chemical and spatial resolution (Owesson-White et al 2012; Robinson et al 2003), but it has rarely been used to map dopaminergic nerve terminal density profiles in discrete brain regions in vivo (Chadchankar and Yavich 2011; Zhang et al 2011).…”

“…These include electrochemical techniques such as fast-scan cyclic voltammetry, constant potential amperometry, and high-speed chronoamperometry (Lee et al 2006; Littrell et al 2012; Park et al 2011; Zhang et al 2011). Fast-scan cyclic voltammetry allows for high chemical and spatial resolution (Owesson-White et al 2012; Robinson et al 2003), but it has rarely been used to map dopaminergic nerve terminal density profiles in discrete brain regions in vivo (Chadchankar and Yavich 2011; Zhang et al 2011). Also, this technique has rarely been used in conjunction with local application of chemicals from micropipettes placed adjacent to the microelectrodes in order to map the density of DA uptake and release from nerve terminals in a given brain area (Bergstrom et al 2011; Howard et al 2011; Owesson-White et al 2012; Park et al 2011; Sugam et al 2012; Wang and Michael 2012).…”

Chemical Analysis of Single Cells

“…This array has been recently used to compare amperometry and fast scan cyclic voltammetry, again for the imaging of exocytosis for a single PC12 cell. 130 In comparison to amperometry, fast scan cyclic voltammetry offered excellent chemical, but poor temporal and spatial resolutions.…”