Capuano C A, Barr G A, Leibowitz S F
Department of Psychology, Fairleigh Dickinson University, Rutherford, NJ 07070.
Pharmacol Biochem Behav. 1989 Jul;33(3):567-72. doi: 10.1016/0091-3057(89)90389-4.
To assess the effects of catecholaminergic drugs on independent feeding during development, preweanling rats were administered amphetamine (AMPH) or chlorpromazine (CPZ) and were allowed to ingest milk through anteriorly located intra-oral cannulas. In 1-hr milk-deprived rat pups, AMPH stimulated milk intake at 3, 7 and 10 days of age and suppressed intake at 15 days. In 22-hr-deprived pups, AMPH had no effect at 3, 7 and 10 days, but reliably suppressed intake at 15 days. CPZ stimulated intake in 3-, 10- and 15-day-old milk-satiated pups. In 22-hr-deprived pups, CPZ had no effect at 3 and 10 days, but stimulated intake at 15 days. While AMPH produced pronounced nonappetitive behavioral activation in conjunction with enhanced intake in 1-hr-deprived pups, AMPH-induced activation occurred without enhanced intake in 22-hr-derived pups. Thus, there was a dissociation between AMPH's effect on milk intake and AMPH-induced nonappetitive behavioral activation. Collectively, the present results support the following conclusions. First, a catecholaminergic system(s) that enhances independent feeding is present very early in postnatal development of the rat. Second, level of food deprivation is an important state-dependent variable when assessing the effects of AMPH and CPZ on independent feeding in preweanling rats.
为了评估儿茶酚胺能药物对发育过程中自主进食的影响，给断奶前的大鼠注射苯丙胺（AMPH）或氯丙嗪（CPZ），并让它们通过位于口腔前部的插管摄取牛奶。在禁食1小时的幼鼠中，AMPH在3、7和10日龄时刺激牛奶摄入量，而在15日龄时抑制摄入量。在禁食22小时的幼鼠中，AMPH在3、7和10日龄时没有影响，但在15日龄时可靠地抑制了摄入量。CPZ刺激了3、10和15日龄饱食牛奶的幼鼠的摄入量。在禁食22小时的幼鼠中，CPZ在3和10日龄时没有影响，但在15日龄时刺激了摄入量。虽然AMPH在禁食1小时的幼鼠中产生了明显的非食欲性行为激活并伴有摄入量增加，但在禁食22小时的幼鼠中，AMPH诱导的激活在摄入量没有增加的情况下发生。因此，AMPH对牛奶摄入量的影响与AMPH诱导的非食欲性行为激活之间存在分离。总体而言，目前的结果支持以下结论。第一，在大鼠出生后的发育过程中，很早就存在一个增强自主进食的儿茶酚胺能系统。第二，在评估AMPH和CPZ对断奶前大鼠自主进食的影响时，食物剥夺程度是一个重要的状态依赖性变量。
