Increased phencyclidine self-administration due to food deprivation: interaction with concentration and training conditions.
Six monkeys were trained to self-administer orally delivered phencyclidine (0.25 mg/ml) under a fixed-ratio 16 (FR-16) schedule. Water was concurrently available under an FF-16 schedule. During initial phencyclidine training, three monkeys were allowed free access to food (food satiation) and three were maintained at 85% of their free-feeding body weights (food deprivation). At the end of the training phase, the food-satiated monkeys were food-deprived. After behavior was stable for ten sessions, all monkeys were food-satiated and tested with a range of phencyclidine concentrations (0.0625-1 mg/ml). They were subsequently food-deprived and tested with concentrations of 0.0312-1 mg/ml, and then they were again food-satiated and tested with 0.0312 and 0.25 mg/ml. The monkeys that were trained to self-administer phencyclidine while food-satiated showed substantial phencyclidine-maintained responding at lower drug concentrations when later tested while food-satiated. In contrast, monkeys that were trained while food-deprived did not respond for phencyclidine in excess of water at the lower concentrations when later tested while food-satiated. Drug-maintained performance during food deprivation did not change systematically as a function of training condition (food deprivation versus food satiation). These results illustrated a marked interaction between drug concentration and the feeding condition and this interaction was modified by training history.
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D005508:Food Deprivation / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D010622:Phencyclidine / Q000008:administration & dosage / Q000494:pharmacology*; D012527:Satiation / Q000502:physiology; D012646:Self Administration
D010622:Phencyclidine