Long-term depression in striatal dopamine release monitored by in vivo voltammetry in free moving rats.

It was proposed to monitor in free moving rats, by in vivo voltammetry, the effects of intracerebroventricular (i.c.v.) administration of drugs known to act on the synthesis of dopamine (DA), using an original multifiber carbon electrode which enables without-discontinuity long-term recordings in extracellular DA release. Results show that i.c.v. administration of alpha-methyl-p-tyrosine, gamma-butyrolactone, and apomorphine induced long-term depression in striatal DA release, over periods of time of more than 24 h. These results are in agreement with the dopaminergic hypothesis; and we conclude that i.c.v. administration of drugs and the use of the multifiber carbon electrode constitutes a valuable tool to monitor DA metabolism in chronically implanted animals.