Dopamine D2 Receptor Priming Enhances Dopaminergic Response to Amphetamine in the Nucleus Accumbens: Role of the D1 and D2 Receptors.

<p>In past work, we have shown neonatal quinpirole (dopamine D₂/D₃ agonist) treatment produces a significant increase in dopamine D₂ receptor sensitivity, a phenomenon known as D₂ receptor priming. Dopamine D₂ receptor priming is common in psychosis. Male and female rats were administered quinpirole (1mg/kg) or saline from postnatal days 1-11 and raised to adulthood (P60). As adults, rats were administered d-amphetamine sulfate (1mg/kg) or saline every other day for 14 days. Approximately 10 min before each amphetamine or saline injection, animals were administered the D1 antagonist SCH 23390 (0.1 mg/kg), the D2 antagonist eticlopride (0.1 mg/kg) or saline. After both injections, rats were placed in a locomotor arena and activity was analyzed for a 10-min period. Results indicated that D₂-priming enhanced locomotor activation effects to amphetamine in both males and females, with females demonstrating higher levels of behavioral activation. SCH 23390 blocked amphetamine sensitization in both males and females to levels below saline controls, whereas eticlopride was more effective in blocking amphetamine sensitization in males as compared to females, although eticlopride did block elevations of behavioral activation in D2-primed males and females. Seven to 10 days after sensitization, microdialysis was performed and amphetamine produced a five-fold increase in dopamine overflow in the nucleus accumbens compared to non D₂-primed rats administered amphetamine. Both D1 and D2 antagonism were effective at blocking amphetamine-induced increases in dopamine overflow. These results show that neonatal quinpirole treatment enhances behavioral activation and dopamine overflow, but there appear to be sex differences in the D2 as compared to D1 response to behavioral activation produced by amphetamine.</p>

Name thesis:degree_name

PhD (Doctor of Philosophy)

Level thesis:degree_level

Dissertation - unrestricted

Discipline thesis:degree_discipline

Biomedical Sciences

Year dc:date.issued

2009

Author dc:creator

• Huggins, Kimberly Norris

• D1 receptor
• D2 priming
• amphetamine
• D2 receptor
• Life Sciences
• Molecular and Cellular Neuroscience
• Neuroscience and Neurobiology

Statement dc:rights

• Copyright by the authors.

Repository record dc:identifier

https://dc.etsu.edu/etd/1796

OAI identifier oai:identifier

oai:dc.etsu.edu:etd-3148