Voltammetric analysis of nigral graft function.

Abstract

Transplantation of immature brain tissue into the developing and adult central nervous system has attracted much attention, both as a tool for studying brain development, '.* and as a potential approach for repairing damaged neuronal circuit^.'^'-^ As presented by several contributors to this volume, intraventricular, intracavity, or dissociated intraparenchymal grafts of the fetal substantia nigra region, placed into striatum that has been depleted of dopamine (DA) by 6-hydroxydopamine (6-OHDA) pretreatment, can restore many of the behavioral dysfunctions induced by such a denervation. 647 Since the substantia nigra transplants produce DA-containing nerve fibers that invade adjacent areas of host striatum, it has been postulated that restoration of behavioral function is the result of this reinnervation of the damaged host striatum by nerve fibers from the graft. There has been little direct evidence thus far, however, to suggest that ingrowing nerve fibers from the grafts actually release neurotransmitters. In recent years, it has become possible to measure changes in the extracellular levels of the monoamine neurotransmitters and their metabolites in the brain using