Dopamine concentration in the cytoplasmic compartment of single neurons determined by capillary electrophoresis.

It has long been a goal of the biochemist to study the chemistry of single cells. This is particularly important in neuroscience, since each cell can maintain a specific function and identity. Investigations into neurotransmitter compartmentalization within the cell body of neurons should lead to an understanding of the role of the cell body in metabolism, uptake and storage of neurotransmitters. Using capillary electrophoresis, it has been possible to separate and detect attomole levels of neurotransmitter in picoliter volumes of cytoplasm withdrawn from single neurons of the pond snail, Planorbis corneus. This work demonstrates, for the first time, the direct determination of the cytoplasmic concentration of dopamine in single, intact neurons.