Microcomputer-controlled voltammetry in the analysis of transmitter release in rat brain.

Microcomputer-based linear sweep voltammetry with carbon-paste electrodes has the following features: Subtraction of the background current produces a voltammogram with three well-resolved peaks: an ascorbate signal reflecting excitatory amino acid release; a uric acid signal that may be related to purine metabolism; and an HVA signal that is an index of dopamine release under certain conditions. Voltammograms from up to eight electrodes (for example, four electrodes in two rats or two electrodes in four rats) can be recorded simultaneously together with motor activity for each rat over extended periods. Electrodes remain stable over periods of many weeks as measured by the constancy of the mean peak height in a 24-hr period. Microcomputers in voltammetry provide flexibility of all recording parameters and a wide variety of methods of analysis. The combination of stable electrodes and the ability to monitor over extended periods means that interactions between transmitters in different brain regions and their relation to physiological processes can be studied.