In Vivo Detection of Neurotransmitters with Fast Cyclic Voltammetry

Electrochemical techniques detect materials by oxidizing them in solution at a positively polarized “working” electrode. The oxidized material gives up electrons that are collected by the working electrode and generate a current flow through it. The detection of this current is the basis of the measurement method. Several compounds of biological interest are oxidizable under these conditions, and are, therefore, said to be “electroactive.” These include the amine neurotransmitters dopamine, noradrenaline (norepinephrine), adrenaline, and serotonin. Other transmitters, such as acetylcholine, γ-amino-butyric acid (GABA), glycine, and glutamate, are not electroactive and are, therefore, not detectable using electrochemical techniques. The neurotransmitter gas nitric oxide is also electroactive and can be detected electrochemically, as can several other compounds of interest in the brain, including ascorbic acid, uric acid, and several metabolites of the amine transmitters.