Busse Gregory D, Lawrence Elizabeth T, Riley Anthony L
Center for Drug and Alcohol Programs, Institute of Psychiatry, Medical University of South Carolina, 67 President St., PO Box 250861, Charleston, SC 29425, USA.
Pharmacol Biochem Behav. 2005 Jul;81(3):459-65. doi: 10.1016/j.pbb.2005.04.003.
The present experiment examined the effects of alcohol preexposure on place conditioning with cocaine, alcohol or the cocaine/alcohol combination. Specifically, 91 male Sprague-Dawley rats were injected i.p. with 1.5 g/kg alcohol (n=46) or vehicle (n=45) every fourth day for 17 days prior to conditioning. On day 21, half of the animals from each preexposure condition were injected with 20 mg/kg cocaine, 1.5 g/kg alcohol or the cocaine/alcohol combination before being restricted for 30 min to a distinctive compartment of a place conditioning apparatus. The remaining subjects were injected with vehicle and restricted to the alternative side of the chamber. The following day, subjects previously given drug (or vehicle) were given vehicle (or drug) and placed in the alternative compartment of the chamber. Following four conditioning cycles, subjects were allowed 15-min access to the entire chamber. Both alcohol- and vehicle-preexposed animals conditioned with cocaine displayed a preference for the cocaine-paired compartment. Those conditioned with alcohol had an aversion to the alcohol-paired compartment. Consistent with our previous work, animals given the cocaine/alcohol combination displayed no compartment preference, indicating that concurrent alcohol affected the reinforcing effects of cocaine. Further, the attenuating effect of concurrent alcohol was unaffected by alcohol history. Under the present parameters, alcohol pretreatment has no effect on the rewarding (and possibly aversive) properties of cocaine alone or the cocaine/alcohol combination. Continued investigation of the conditions under which preexposure to alcohol might modulate the aversive/reinforcing properties of a cocaine/alcohol combination may be important for understanding vulnerability to the use and/or abuse of this drug combination.
本实验研究了预先接触酒精对可卡因、酒精或可卡因/酒精组合进行位置条件反射的影响。具体而言，91只雄性斯普拉格-道利大鼠在条件反射训练前每隔四天腹腔注射1.5 g/kg酒精（n = 46）或赋形剂（n = 45），持续17天。在第21天，来自每种预先接触条件的动物中有一半在被限制于位置条件反射装置的一个独特隔室30分钟之前，注射20 mg/kg可卡因、1.5 g/kg酒精或可卡因/酒精组合。其余的动物注射赋形剂并被限制在实验箱的另一侧。第二天，之前接受过药物（或赋形剂）注射的动物接受赋形剂（或药物）注射，并被放置在实验箱的另一个隔室中。经过四个条件反射循环后，让动物有15分钟的时间可以进入整个实验箱。预先接触酒精和赋形剂且用可卡因进行条件反射的动物都表现出对与可卡因配对的隔室的偏好。用酒精进行条件反射的动物则对与酒精配对的隔室表现出厌恶。与我们之前的研究一致，给予可卡因/酒精组合的动物没有表现出对隔室的偏好，这表明同时摄入酒精会影响可卡因的强化作用。此外，同时摄入酒精的减弱作用不受酒精接触史的影响。在当前参数下，酒精预处理对单独使用可卡因或可卡因/酒精组合的奖赏（可能还有厌恶）特性没有影响。继续研究预先接触酒精可能调节可卡因/酒精组合的厌恶/强化特性的条件，对于理解对这种药物组合使用和/或滥用的易感性可能很重要。
