Study of Brain Noradrenergic Neurons by Use of In Vivo Voltammetry

Abstract

Since the introduction of in vivo electrochemistry in the study of brain neurochemistry, most applicatons have been made within the nigrostriatal dopamine (DA) system. There are many reasons investigators have been so attracted by this brain region: The striatum contains the highest density of DA-containing neuronal terminals of all the brain. This region is also the largest catecholamine (CA) area of the brain with an almost exclusive dopaminergic innervation. It is easily accessible to investigation with carbon electrodes. Finally, many biochemical data are available concerning the metabolism of DA within this area. From the early in vivo electrochemical studies it was learned that the in vivo study of catechol metabolism in the brain is a relatively difficult task, requiring selective and sensitive methods of detection. As a result, we, like other investigators, have attempted to develop an electrochemical method allowing for selective in vivo monitoring of DA metabolism in the striatum (Gonon et al., 1980). This method enables us to study various features of DA metabolism in the striatum (Gonon et al., 1981b, 1984a; Gonon and Buda, 1985; Gonon, this volume), as well as in other dopaminergic regions (Buda et al., 1981). The use of carbon fiber microelectrodes, because of their size and sensitivity, allow for investigation of other catecholaminergic regions, such as those innervated by noradrenaline (NA)-containing neuronal systems.