CARBON-FIBER MICROELECTRODES FOR CONCOMITANT IN-VIVO ELECTROPHYSIOLOGICAL AND VOLTAMMETRIC MEASUREMENTS - NO RECIPROCAL INFLUENCES

Differential pulse voltammetry and more recently cyclic voltammetry ha ve been successfully used to monitor basal levels of endogenous chemic als by means of treated carbon fibre microbiosensors inserted in speci fic brain regions. In this study, feasibility of concomitant in vivo r ecordings of stable electrophysiological signals and basal ascorbate, catecholaminergic and indolaminergic voltammetric peaks at the same ce rebral site by means of a single electrically treated carbon fibre mic ro electrode (microbiosensor) is presented. The results indicate that these two independent techniques can be combined in vivo at a single e lectrode, and that voltammetric measurements of unstimulated levels of extracellular compounds do not alter concomitant basal cell firing fo r a period long enough (more than 6 h) to allow pharmacological manipu lations.