Acquisition of intravenous cocaine self-administration with concurrent access to food in cynomolgus monkeys.
The present study used a concurrent schedule of food and drug delivery in socially housed male cynomolgus monkeys (Macacafascicularis; N = 15) to study variables that influence cocaine acquisition. Each monkey was implanted with subcutaneous vascular access ports, and responding was maintained under a concurrent food, saline schedule with the lever associated with each stimulus presentation varied daily. Next, increasing cocaine doses (0.003-0.3 mg/kg/inj) were concurrently available with food for at least 5 consecutive sessions per dose. Under these conditions, an unexpected lever bias emerged in all 15 monkeys. The development of the lever bias could not be predicted on the basis of cocaine dose or total intake and was not related to social rank. These findings suggest that in monkeys, concurrent fixed-ratio schedules of food and cocaine presentation may result in persistent biased responding that overshadows cocaine preference in studies of acquisition.
Morgan
D
D
Department of Physiology and Pharmacology, Center for the Neurobiological Investigation of Drug Abuse, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1083, USA.
Nader
M A
MA
D000818:Animals; D001069:Appetite Regulation; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology; D003042:Cocaine / Q000008:administration & dosage* / Q000494:pharmacology; D004435:Eating / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D007275:Injections, Intravenous; D008252:Macaca fascicularis; D008297:Male; D023421:Models, Animal; D012646:Self Administration
D000697:Central Nervous System Stimulants; D003042:Cocaine