Comparison of the reinforcing efficacy of cocaine and procaine in rhesus monkeys responding under a progressive-ratio schedule.

摘要: Rhesus monkeys (n=5) were prepared with chronic IV catheters and trained to lever press under a PR schedule of drug injection. The consisted five components, each made up four trials (i.e., 20 total). Each trial within component had the same response requirement. requirement in first was 120/trial doubled successive components maximum 1920 fifth. A ended an injection or expiration 12-min limited hold (LH). inter-trial interval (ITI) 15 30 min. Following LH, all stimulus lights extinguished responding no consequence for remainder trial. session when either injections self-administered not met LH two consecutive trials. number injections/session responses/session increased dose cocaine (0.012–0.1 mg/kg per injection) procaine (0.12–2.0 at both ITI values. At 15-min ITI, decreased again higher doses some procaine. maximum, maintained significantly more min than it In contrast, increase did by Cocaine approximately 10-fold potent responses but These results are consistent previous studies demonstrating that is efficacious positive reinforcer Moreover, they extend recent findings suggesting provides measure performance amenable statistical analysis may, therefore, be useful establishing reliable differences among drugs terms relative reinforcing efficacy. Reliable quantification between-drug efficacy can enhance only estimates abuse liability also pharmacological central mechanisms mediating effects.