ABSTRACT
The intrinsic properties of ultramicroelectrodes make them par-
ticularly suitable for electrochemical detection of exocytosis at the
single-cell level. During the nineties, carbon fiber ultramicroelec-
trodes (5-10 μm in diameter) used in the “semiartificial synapse”
configuration were essential for improving the understanding of
the mechanism of exocytotic release not only by addressing the
precise detection and monitoring of small effectors fluxes but also
by unraveling multiple factors governing release, multiple vesicular
populations, fusion pore kinetics, etc. Over the past 10 years, new
questions appeared, thus requiring global monitoring of a release
event, enhancing the spatial resolution of the detection or avoiding
all the experimental problems related to cell variability. Therefore,
the early simple microelectrode composed of a fiber with possible
surface treatment could not solve these issues and was required
to be adapted, modified, or even integrated in multicomponent
microassemblies. In this chapter, we wish to present how exocytosis
may be electrochemically investigated in real time at the single-cell
level and how the seminal carbon fiber electrode method evolved
over 20 years. The examples produced to illustrate this chapter
are obviously not exhaustive, taking into account the tremendous
number of studies dealing with this expanding domain. The reader
of this chapter is thus encouraged to consult the last comprehensive
reviews that have blossomed during the past five years [1-8].
