Simultaneous voltammetric and chemical monitoring of dopamine release in situ.

The validity of voltammetric monitoring of stimulated dopamine (DA) release was tested by simultaneous chemical assay of the extracellular fluid region next to the tip of a selective Nafion-coated graphite voltammetric electrode. Micro alumina probes were positioned next to the recording electrode tip to adsorb released catecholamines. The catecholamines were desorbed into microvolumes of acid and analyzed by very sensitive HPLC assays to provide unequivocal chemical verification of the electrochemical signals. The results fully confirm that selective voltammetric electrodes can detect released DA and that the concentrations determined voltammetrically or chemically agree well.