Quantitative chemical analysis of single cells.

Area of Science:

• Neuroscience
• Biochemistry
• Analytical Chemistry

Background:

• Exocytosis is crucial for intercellular communication, involving vesicle fusion and content release.
• The rapid nature of exocytosis (milliseconds) necessitates sensitive detection methods with fast temporal response.
• Catecholamines are key signaling molecules released via exocytosis.

Purpose of the Study:

• To present electrochemistry at carbon-fiber microelectrodes as a sensitive method for time-resolved exocytosis studies.
• To demonstrate the capability of this technique for observing low-level release of electroactive catecholamines.
• To determine the kinetics and molecular count of quantal release events.

Main Methods:

• Utilizing electrochemistry at carbon-fiber microelectrodes.
• Employing constant-potential amperometry for detection.
• Monitoring the release of electroactive catecholamines during exocytosis.

Main Results:

• Demonstrated time-resolved observation of exocytosis.
• Achieved sensitive detection of released catecholamines at very low levels.
• Quantified the number of molecules released and determined release kinetics.

Conclusions:

• Electrochemistry at carbon-fiber microelectrodes is a powerful tool for studying exocytosis.
• The rapid response time of microelectrodes is ideal for monitoring dynamic exocytosis processes.
• This technique provides insights into the kinetics and quantal nature of neurotransmitter release.