Winsauer P J, Moerschbaecher J M, Molina P E, Roussell A M
Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans 70112-1393, USA.
Behav Pharmacol. 2003 Jul;14(4):295-306. doi: 10.1097/01.fbp.0000081785.35927.08.
Previous studies have suggested that the effects of contingent (response dependent) and noncontingent (response independent) cocaine administration may differ, which could limit the generality and validity of laboratory studies that use only noncontingent administration. Therefore, two separate three-component multiple schedules of operant responding were used to examine the effects of both types of cocaine administration on the acquisition and performance of response sequences, in four rhesus monkeys. In one multiple schedule, responding under a fixed-ratio (FR) 60 schedule was followed by intravenous (i.v.) saline or cocaine (0.0032-0.32 mg/kg per infusion), whereas responding in the other two components (i.e. acquisition and performance) was followed by food presentation. In the second multiple schedule, the cocaine administration component consisted of a variable-time (VT) schedule that mimicked each subject's pattern of self-administration. When compared to saline administration, increasing infusion doses of cocaine decreased overall response rates comparably in both food-maintained components, irrespective of the cocaine contingency. The 0.1-0.32 mg/kg infusion doses also increased the percentage of errors in 2 of 4 subjects; however, these disruptions in accuracy were not differentially associated with the type of cocaine administration and generally occurred at doses that produced large rate-decreasing effects. Taken together, these data suggest that the effects of cocaine on complex operant behavior in monkeys may not differ substantially as a function of contingent or noncontingent administration.
以往的研究表明，依随性（依赖反应）和非依随性（独立于反应）给予可卡因的效果可能不同，这可能会限制仅使用非依随性给药的实验室研究的普遍性和有效性。因此，在4只恒河猴中，采用了两种独立的三成分操作性反应多重时间表，以检验两种类型的可卡因给药对反应序列习得和表现的影响。在一种多重时间表中，在固定比率（FR）60时间表下的反应之后静脉注射（i.v.）生理盐水或可卡因（每次输注0.0032 - 0.32 mg/kg），而在其他两个成分（即习得和表现）中的反应之后给予食物。在第二种多重时间表中，可卡因给药成分由一个可变时间（VT）时间表组成，该时间表模仿了每个受试者的自我给药模式。与给予生理盐水相比，增加可卡因输注剂量在两个食物维持成分中均同等程度地降低了总体反应率，而与可卡因的依随性无关。0.1 - 0.32 mg/kg的输注剂量也增加了4只受试者中2只的错误百分比；然而，这些准确性的干扰与可卡因给药类型没有差异关联，并且通常发生在产生大幅速率降低效应的剂量下。综上所述，这些数据表明，可卡因对猴子复杂操作性行为的影响可能不会因依随性或非依随性给药而有实质性差异。
