Voltammetry in the striatum of chronic freely moving XXXX : detection of catechols and @entity620 .

@entity35 @entity1508 @entity4925 @entity620 @entity4927 @entity935 @entity1767 @entity505 @entity4944 @entity22292 @entity6153
Differential pulse voltammetry used in combination with an electrochemically treated @entity505 fiber electrode allowed to detect @entity620 (AA) and @entity4925 ( @entity4925 ) in the striatum of unanaesthetized freely moving @entity35 . @entity505 fiber electrodes were implanted under light @entity1508 anaesthesia. When the @entity35 recovered from anaesthesia, voltammograms were recorded every 2.5 min for about 5 h. During the last 3 h the signals corresponding to AA and @entity4925 appeared stable and reproducible, allowing comparisons between control and pharmacological experiments. After the in vivo experiments, the electrodes were calibrated in AA and @entity4925 solutions. Striatal AA and @entity4925 levels were thus estimated to be 306 and 17.7 microM respectively. @entity4925 signals were increased by @entity1767 and @entity22292 , decreased by @entity4944 and suppressed by @entity4927 . In pargyline pretreated @entity35 the @entity6153 signal slightly re-appeared after @entity4944 injections. This signal was attributed to @entity935 (DA) and estimated to a concentration less than 50 nM DA. The AA current recorded in the striatum was not modified when dopaminergic terminals selectively degenerated. The AA signal was decreased by @entity22292 or @entity1508 anaesthesia and increased by @entity4944 injections. This latter effect depended on the presence of dopaminergic terminals. This shows that the increasing current effect of @entity4944 , previously observed by non-selective techniques, should be attributed to AA rather than DA. These results confirm that the @entity6153 compound electrochemically detected in the striatum is the direct metabolite of the DA, i.e. @entity4925 , and support the thesis of a functional relationship between AA levels and dopaminergic neurotransmission.
