Abstract
The effect of repeated administration of cocaine on presynaptic D2 autoreceptor sensitivity in synaptosomes was studied. In rats treated chronically with saline, the dopamine D2 agonist 2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin (N-0437) caused a significant inhibition of the Ca2+-evoked 3H-DA release from synaptosomes prepared from the nucleus accumbens and from the striatum; this effect was blocked by the D2 antagonist sulpiride. However, chronic cocaine pretreatment abolished the effect of N-0437 in both areas, suggesting a subsensitivity of release-modulating terminal DA autoreceptors. Subsensitive DA autoreceptors would enhance stimulated DA release from mesolimbic and nigrostriatal terminals and may play a role in the behavioral sensitization observed in this paradigm.
Original language | English (US) |
---|---|
Pages (from-to) | 457-461 |
Number of pages | 5 |
Journal | Pharmacology, Biochemistry and Behavior |
Volume | 36 |
Issue number | 3 |
DOIs | |
State | Published - Jul 1990 |
Externally published | Yes |
Keywords
- Behavioral sensitization
- Chronic cocaine
- DA autoreceptor
- DA release
ASJC Scopus subject areas
- Biochemistry
- Toxicology
- Pharmacology
- Clinical Biochemistry
- Biological Psychiatry
- Behavioral Neuroscience