Electrochemistry of Single-Vesicle Events

Abstract

Neuronal transmission relies on electrical signals and the transfer of chemical signals from one neuron to another. Chemical messages are transmitted from presynaptic neurons to neighboring neurons through the triggered fusion of neurotransmitter-filled vesicles with the cell plasma membrane. This process, known as exocytosis, involves the rapid release of neurotransmitter solutions that are detected with high affinity by the postsynaptic neuron. The type and number of neurotransmitters released and the frequency of vesicular events govern brain functions such as cognition, decision making, learning, and memory. Therefore, to understand neurotransmitters and neuronal function, analytical tools capable of quantitative and chemically selective detection of neurotransmitters with high spatiotemporal resolution are needed. Electrochemistry offers powerful techniques that are sufficiently rapid to allow for the detection of exocytosis activity and provides quantitative measurements of vesicle neurotransmitter content and neurotransmitter release from individual vesicle events. In this review, we provide an overview of the most commonly used electrochemical methods for monitoring single-vesicle events, including recent developments and what is needed for future research.

Recent developments concerning the investigation of exocytosis with amperometry

“…Second, new analytical tools, essentially based on a coupling of methods with amperometry (microchips, fluorescence, cytometry) or the development of nanoprobes, blossomed and offered encouraging and very exciting results. The main works resulting from the 2018e21 period correspond well to the scientific trends already identified by more comprehensive reviews [1,5]: (1) The use of nanoelectrodes offers many new opportunities related to intracellular analysis or within the synapse. (2) Amperometry needs to be integrated with other techniques, especially fluorescence imaging, to provide a comprehensive view of the entire exocytotic event.…”

Chemical Imaging and Analysis of Single Nerve Cells by Secondary Ion Mass Spectrometry Imaging and Cellular Electrochemistry

“…Owing to outstanding spatial-temporal resolution and high sensitivity, amperometry has become a powerful tool to study exocytosis for many cell types, including primary cultures, nerve cells, other secretory cell models (chromaffin cells, pheochromocytoma cells, PC12 cells, mast cells, and pancreatic β cells), neurons, synapses, and single nerve cell varicosities ( Keighron et al, 2020 ). Quantal release was observed from axonal varicosities of midbrain dopamine neurons consisting of small synaptic vesicles by Pothos et al (1998) .…”

Single‐Carbon‐Fiber‐Powered Microsensor for In Vivo Neurochemical Sensing with High Neuronal Compatibility

“…mm) resolution. [5] To this end, electrochemical methods based on microelectrodes have received intensive attention since the successful recording of the first voltammogram in rat brain in 1973. [6] While several electrochemical methods have thus been used for in vivo monitoring of chemistry in brain, [5a, 6, 7] most of them are based on polarizing working electrode by external voltage to drive oxidation/ reduction reactions of the target neurochemicals (i.e., based on an electrolytic-cell mechanism).…”