Guzman Daniel, Ettenberg Aaron
Behavioral Pharmacology Laboratory, Department of Psychology, University of California, Santa Barbara, California 93106-9660, USA.
Behav Pharmacol. 2007 Feb;18(1):53-60. doi: 10.1097/FBP.0b013e3280144ac9.
In previous work from our laboratory, animals running for intravenous cocaine developed a unique approach-avoidance 'retreat behavior' that was hypothesized to result from cocaine's well documented reinforcing (positive) and anxiogenic (negative) properties. To assess the role of central mechanisms in producing cocaine's positive and negative effects, we assessed whether or not animals running a straight alley for intracerebroventricular applications of cocaine would produce a similar behavioral profile to that previously observed with intravenous applications. Retreat frequency and location were measured in male Sprague-Dawley rats trained to run an alley for one of four doses of intracerebroventricular-administered cocaine (0, 25, 50 or 100 microg cocaine/infusion). Testing involved a single trial per day over 14 consecutive days with a single infusion of cocaine delivered upon goal box entry. The 100 and 50 microg intracerebroventricular cocaine groups exhibited significantly higher retreat frequencies than the 25 and 0 microg groups and the nature and magnitude of the behavior was comparable to that previously observed with intravenous cocaine. These results suggest that the intracerebroventricular self-administration of cocaine results in mixed positive and negative consequences and therefore likely stem from the drug's actions within the central nervous system.
在我们实验室之前的研究中，为获取静脉注射可卡因而奔跑的动物会产生一种独特的趋近-回避“退缩行为”，据推测这是由可卡因已被充分证明的强化（积极）和致焦虑（消极）特性所致。为评估中枢机制在产生可卡因的积极和消极作用中的作用，我们评估了为接受脑室内注射可卡因而在直道上奔跑的动物是否会产生与之前静脉注射时观察到的类似行为模式。在经过训练在直道上奔跑以接受四种剂量（0、25、50或100微克可卡因/次输注）之一的脑室内注射可卡因的雄性斯普拉格-道利大鼠中，测量退缩频率和位置。测试包括连续14天每天进行一次试验，在进入目标箱时给予单次可卡因输注。100微克和50微克脑室内注射可卡因组的退缩频率显著高于25微克和0微克组，且该行为的性质和程度与之前静脉注射可卡因时观察到的相当。这些结果表明，脑室内自我给药可卡因会导致积极和消极后果的混合，因此可能源于该药物在中枢神经系统内的作用。
