Papasava M, Singer G
Psychopharmacology (Berl). 1985;85(4):419-25. doi: 10.1007/BF00429657.
Food deprivation significantly increases self-administration of cocaine in both rats and rhesus monkeys. The objective in the present investigation was to determine the effects of varying deprivational states on the level of IV low-dose (0.1 mg/kg/infusion) cocaine self-administration in rats. In the first experiment, 32 naive rats were assigned randomly to four equal-sized groups. Two groups self-administered cocaine, the other two saline over two consecutive 10-day phases. Across phase 1 all animals were free-feeding (FF), while in phase 2, one cocaine- and one saline-reinforced group were subjected to restricted feeding until they reached 80% free-feeding weight (FFW). Results showed that cocaine-reinforced responding was related inversely to body weight. In experiment 2 another 32 rats, reduced to 80% FFW, were assigned to four equal-sized groups. Two groups self-administered cocaine, the other two saline over two consecutive 10-day phases. Across phase 1 all animals were maintained at 80% FFW, while in phase 2, one cocaine- and one saline-reinforced group were abruptly food satiated. Findings showed that cocaine-reinforced responding decreased rapidly to low levels. Finally, the group of cocaine-reinforced rats maintained at 80% FFW across both phases of experiment 2 were also abruptly food satiated. Again, responding decreased rapidly to low levels.
食物剥夺显著增加大鼠和恒河猴对可卡因的自我给药量。本研究的目的是确定不同剥夺状态对大鼠静脉注射低剂量（0.1毫克/千克/输注）可卡因自我给药水平的影响。在第一个实验中，32只未接触过实验的大鼠被随机分为四个大小相等的组。两组自我给药可卡因，另外两组在两个连续的10天阶段中自我给药生理盐水。在第1阶段，所有动物自由进食（FF），而在第2阶段，一个可卡因强化组和一个生理盐水强化组进行限制进食，直到它们达到自由进食体重（FFW）的80%。结果表明，可卡因强化反应与体重呈负相关。在实验2中，另外32只大鼠体重降至FFW的80%，被分为四个大小相等的组。两组自我给药可卡因，另外两组在两个连续的10天阶段中自我给药生理盐水。在第1阶段，所有动物维持在FFW的80%，而在第2阶段，一个可卡因强化组和一个生理盐水强化组突然达到食物饱足状态。结果显示，可卡因强化反应迅速降至低水平。最后，在实验2的两个阶段都维持在FFW的80%的可卡因强化大鼠组也突然达到食物饱足状态。同样，反应迅速降至低水平。
