Abstract
The ability of dopamine (DA) agonists and antagonists to modulate the K+-evoked overflow of radioactivity from superfused slices of prefrontal cortex of the rat, preincubated with [3H]DA in the presence of 1 μM desipramine, was examined. Apomorphine and the putative autoreceptor-selective DA agonist EMD 23 448 inhibited the K+-evoked overflow of radioactivity, while the DA antagonist sulpiride enhanced the evoked overflow in a dose-dependent and stereoselective manner. The latter effect was partially reversed by EMD 23 448. More than 95% of the radioactivity retained by the slices chromatographed with DA, while deaminated metabolites represented the majority of both the basal efflux (84% metabolites, 4-5% DA) and evoked overflow (84% metabolites, 14% DA) of radioactivity. These findings indicate that mesoprefrontal DA neurons possess release-modulating nerve terminal autoreceptors. Previous studies have shown that these neurons lack synthesis-modulating autoreceptors. Thus, autoreceptors on prefrontal DA terminals appear to be coupled to regulation of the release but not the synthesis of DA.
Original language | English (US) |
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Pages (from-to) | 1053-1059 |
Number of pages | 7 |
Journal | Neuropharmacology |
Volume | 26 |
Issue number | 8 |
DOIs | |
State | Published - Aug 1987 |
Externally published | Yes |
Keywords
- brain slices
- dopamine autoreceptors
- dopamine release
- prefrontal cortex
ASJC Scopus subject areas
- Pharmacology
- Cellular and Molecular Neuroscience