Analytical chemistry in microenvironments: single nerve cells

Ewing, Andrew G.; Strein, Timothy G.; Lau, Yau Yi

doi:10.1021/ar00022a002

Cited by 85 publications

(44 citation statements)

References 54 publications

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“…To obtain a complete understanding of dopamine neurotransmission, one would like to probe directly the spatial and tem-poral concentration changes that occur from the site of release to the interactions with a receptor (Ewing et al, 1992). Although this is not currently possible with any method, voltammetry as applied here provides temporally resolved information concerning the concentration ofdopamine in the extrasynaptic compartment of extracellular fluid that is released from sites immediately adjacent to the sensor tip.…”

Section: Discussionmentioning

confidence: 99%

Efflux of dopamine from the synaptic cleft in the nucleus accumbens of the rat brain

et al. 1994

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Synaptic release of dopamine in the nucleus accumbens of the intact rat brain elicited by a single electrical impulse applied to ascending dopaminergic fibers results in extracellular concentrations sufficient to bind the known dopamine receptors. The dopamine concentration observed after four rapid, sequential pulses is exactly four times greater and is unaffected by pharmacological antagonism of dopamine uptake and receptor sites at supramaximal concentrations. Thus, dopamine efflux from the synaptic cleft is not restricted by binding to intrasynaptic proteins on the time scale of the measurements (50–100 msec). The extracellular concentration, as a result of a single stimulus pulse, is 0.25 microM and is rapidly removed by extrasynaptic uptake. This maximal, transient concentration of dopamine is 60 times higher than steady-state concentrations reported previously using dialysis techniques, illustrating that dopamine extracellular concentrations are spatially and temporally heterogenous. In contrast to ACh transmission at the neuromuscular junction, the dopamine synapse in the telencephalon is designed for the effective efflux of dopamine from the synaptic cleft to the extrasynaptic compartment during neurotransmission.

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Section: Discussionmentioning

confidence: 99%

Efflux of dopamine from the synaptic cleft in the nucleus accumbens of the rat brain

et al. 1994

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“…Capillary electrophoresis is an emerging technique capable of rapidly determining multiple chemical species in picoliter and femtoliter biological samples, including single cells (5)(6)(7)(8)(9)(10). This technique has been used successfully to develop quantitative analyses for chemicals in single whole nerve cells, including large invertebrate cells (8) and small mammalian erythrocytes (9).…”

Section: Activitymentioning

confidence: 99%

Discovery of endogenous catecholamines in lymphocytes and evidence for catecholamine regulation of lymphocyte function via an autocrine loop.

Bergquist¹,

Tarkowski²,

Ekman³

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

345

262

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Evidence has been obtained that catecholamines and their metabolites are present in single lymphocytes and extracts of T-and B-ceUl clones by use of capiUlary electrophoresis with electrochemical detection. Pharmacological inhibition of tyrosine hydroxylase reduces observed catecholamine levels, suggesting catecholamine synthesis by lymphocytes. Intracelular dopamine levels are shown to be increased by extracellular dopamine, suggesting a cellular-uptake mechanism. Furthermore, incubation with either dopamine or L-dihydroxyphenylalanine, a precursor of dopamine, results in a dosedependent inhibition of lymphocyte proliferation and differentiation. Together, these results suggest the presence of an autocrine loop whereby lymphocytes down-regulate their own activity.

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“…Only a few examples of intracellular electrochemical measurements have been reported to date (21)(22)(23). One of the main obstacles here is the electrode size and geometry; even a sharp, conical electrode puncturing a lipid membrane may cause a solution leakage (20).…”

mentioning

confidence: 99%

Nanoelectrochemistry of mammalian cells

Sun

Laforge

Abeyweera

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

207

200

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There is a significant current interest in development of new techniques for direct characterization of the intracellular redox state and high-resolution imaging of living cells. We used nanometersized amperometric probes in combination with the scanning electrochemical microscope (SECM) to carry out spatially resolved electrochemical experiments in cultured human breast cells. With the tip radius Ϸ1,000 times smaller than that of a cell, an electrochemical probe can penetrate a cell and travel inside it without apparent damage to the membrane. The data demonstrate the possibility of measuring the rate of transmembrane charge transport and membrane potential and probing redox properties at the subcellular level. The same experimental setup was used for nanoscale electrochemical imaging of the cell surface.charge transfer ͉ membrane potential ͉ scanning electrochemical microscopy ͉ voltammetry

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Analytical chemistry in microenvironments: single nerve cells

Cited by 85 publications

References 54 publications

Efflux of dopamine from the synaptic cleft in the nucleus accumbens of the rat brain

Efflux of dopamine from the synaptic cleft in the nucleus accumbens of the rat brain

Discovery of endogenous catecholamines in lymphocytes and evidence for catecholamine regulation of lymphocyte function via an autocrine loop.

Nanoelectrochemistry of mammalian cells

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