Back to Search
Start Over
Delay discounting of oral morphine and sweetened juice rewards in dependent and non-dependent rats
- Source :
- Psychopharmacology. 231(13)
- Publication Year :
- 2013
-
Abstract
- Opioid-dependent humans are reported to show accelerated delay discounting of opioid rewards when compared to monetary rewards. It has been suggested that this may reflect a difference in discounting of consumable and non-consumable goods not specific to dependent individuals. Here, we evaluate the discounting of similar morphine and non-morphine oral rewards in dependent and non-dependent rats We first tested the analgesic and rewarding effects of our morphine solution. In a second experiment, we assigned rats randomly to either dependent or non-dependent groups that, 30 min after daily testing, received 30 mg/kg subcutaneous dose of morphine, or saline, respectively. Delay discounting of drug-free reward was examined prior to initiation of the dosing regimen. We tested discounting of the morphine reward in half the rats and retested the discounting of the drug-free reward in the other half. All tests were run 22.5 h after the daily maintenance dose. Rats preferred the morphine cocktail to the drug-free solution and consumed enough to induce significant analgesia. The control quinine solution did not produce these effects. Dependent rats discounted morphine rewards more rapidly than before dependence and when compared to discounting drug-free rewards. In non-dependent rats both reward types were discounted similarly. These results show that morphine dependence increases impulsiveness specifically towards a drug reward while morphine experience without dependence does not.
- Subjects :
- Male
media_common.quotation_subject
Analgesic
Choice Behavior
Beverages
Reward
medicine
Animals
Rats, Long-Evans
Oral morphine
health care economics and organizations
media_common
Pharmacology
Discounting
Morphine
Maintenance dose
Delay discounting
Addiction
Rats
Analgesics, Opioid
Opioid
Delay Discounting
Anesthesia
Sweetening Agents
Impulsive Behavior
Psychology
Morphine Dependence
psychological phenomena and processes
medicine.drug
Subjects
Details
- ISSN :
- 14322072
- Volume :
- 231
- Issue :
- 13
- Database :
- OpenAIRE
- Journal :
- Psychopharmacology
- Accession number :
- edsair.doi.dedup.....72ee01cb280653ed67f15d7a63f6b1a0