Abstract
The effects of dizocilpine and buprenorphine pretreatment on behavior reinforced by orally delivered phencyclidine (PCP) and saccharin, and on PCP withdrawal-induced disruptions in food-maintained responding were examined. Sixteen male rhesus monkeys were used in six different experimental protocols. Two groups of monkeys (N = 4-5) self-administered PCP (0.25 mg/ml) and water under concurrent FR 16 schedules, and were pretreated with IM injections of saline, and dizocilpine (0.001-0.1 mg/kg), or buprenorphine (0.003-0.8 mg/kg) 30 min before the 3-h sessions for 5 days. Two other groups (N = 5) were treated similarly except they had access to saccharin (0.03% or 0.3% w/v) and water under concurrent FR 16 schedules. In two other groups (N = 3), the effects of saline, dizocilpine (0.005-0.1 mg/kg), or buprenorphine (0.2 and 0.8 mg/kg) pretreatment were studied on PCP (0.25 mg/ml) withdrawal-induced disruptions in food-maintained responding. Dizocilpine and buprenorphine reduced both PCP (0.25 mg/ml) and saccharin (0.03% or 0.3% w/v) self-administration, especially at the 0.1-mg/kg dizocilpine dose and 0.2-mg/kg buprenorphine dose. Dizocilpine attenuated the PCP withdrawal effect, but buprenorphine had no effect on behavioral disruptions induced by PCP withdrawal. When dizocilpine was administered 2 days after PCP withdrawal began, the withdrawal effects were almost completely reversed. These results suggest that although drugs from the same and different pharmacological classes can suppress self-administration of drug and nondrug reinforcers, the same doses may produce an opposite effect or no effect on food-maintained behavior during PCP withdrawal.
Original language | English (US) |
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Pages (from-to) | 723-732 |
Number of pages | 10 |
Journal | Pharmacology, Biochemistry and Behavior |
Volume | 48 |
Issue number | 3 |
DOIs | |
State | Published - Jul 1994 |
Bibliographical note
Funding Information:The authors appreciate the generosity of Merck & Co., Inc., Rah-way, N J, for the gift of dizocilpine. They are also grateful to Dan Lackas, Curtis Ohrt, and Sherry Thompson for technical assistance and to Dr. Sandra Comer, Laura Curtis, Dan Lackas, and Joyce Rawleigh for their critical review of the manuscript. This work was supported by U.S. Public Health Service Research Grant R01 DA 02486 and a training Grant T32 DA 07097 (J. Rodefer) from the National Institute on Drug Abuse. Portions of this work were presented at the 100th annual meeting of the American Psychological Association, Washington, DC, August, 1992.
Keywords
- Buprenorphine
- Dizocilpine
- MK-801
- Monkeys
- Saccharin
- Self-administration
- Withdrawal