Abstract
Rats were trained on a d-amphetamine (1 mg/kg) vs. saline discrimination task using food-maintained responding (fixed ratio = 25). In extinction tests, drug-appropriate responding decreased as the dose of amphetamine was substituted for the training dose decreased. The dopamine D2/D3 receptor agonist (±)7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) substituted fully for the amphetamine discriminative stimulus at the higher doses examined (0.1, 0.3, 1.0 mg/kg). This substitution was accompanied by a substantial decrease in overall response rates. Eticlopride, a dopamine D2/D3 receptor antagonist, partially blocked 7-OH-DPAT substitution. Thus, at the higher doses, 7-OH-DPAT shared sufficient discriminative stimulus properties with the amphetamine to prompt full substitution. Eticlopride antagonism suggests a role for the D2/D3 dopamine receptor in this substitution.
| Original language | English |
|---|---|
| Pages (from-to) | 485-490 |
| Number of pages | 6 |
| Journal | Pharmacology Biochemistry and Behavior |
| Volume | 58 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 1997 |
Bibliographical note
Funding Information:This work was funded by USPHS grants DA05312 and DA06924 to M. T. Bardo. R. A. Bevins was supported by a National Research Service Award DA05623 while preparing this report for publication. We thank Melinda Marion, Kalpana Shanmugham and Amy Williamson for their assistance in conducting the experiment. We are also grateful to James Rowlett for helpful discussions of this work and to Thomas Kelly and Patricia Robinet for their comments on an earlier version of this manuscript.
Funding
This work was funded by USPHS grants DA05312 and DA06924 to M. T. Bardo. R. A. Bevins was supported by a National Research Service Award DA05623 while preparing this report for publication. We thank Melinda Marion, Kalpana Shanmugham and Amy Williamson for their assistance in conducting the experiment. We are also grateful to James Rowlett for helpful discussions of this work and to Thomas Kelly and Patricia Robinet for their comments on an earlier version of this manuscript.
| Funders | Funder number |
|---|---|
| National Institute on Drug Abuse | P50DA005312 |
| U.S. Public Health Service | DA05312, DA05623, DA06924 |
Keywords
- Amphetamine
- D2 and D3 receptors
- Dopamine
- Drug discrimination
- Eticlopride
- Operant conditioning
ASJC Scopus subject areas
- Biochemistry
- Toxicology
- Pharmacology
- Clinical Biochemistry
- Biological Psychiatry
- Behavioral Neuroscience