Hunt P S, Kraebel K S, Rabine H, Spear L P, Spear N E
Center for Developmental Psychobiology, Binghamton University, NY 13902-6000.
Dev Psychobiol. 1993 Apr;26(3):133-53. doi: 10.1002/dev.420260302.
Several studies have confirmed that diet selection patterns of adult rats are at least partially established as a result of early experiences with food-related stimuli present in the milk of a lactating female (e.g., Capretta & Rawls, 1974; Galef & Clark, 1972; Galef & Henderson 1972). The present experiments were designed to investigate whether preweanling rats would similarly modify their acceptance of an ethanol solution following exposure to this cue in a nursing context. In Experiment 1, 8-, 12-, and 16-day-old rats were given ethanol, delivered intraorally in compound with milk, while given the opportunity to suckle an anesthetized dam. Subsequent testing revealed that 12- and 16-day-old subjects evidenced enhanced intake of the ethanol relative to controls, while 8-day-olds did not. Finally, the oldest (16 days of age) subjects also expressed a conditioned aversion to the milk when tested 24 hr after conditioning and ethanol-ingestion testing. Experiment 2 demonstrated that the critical factor for ethanol conditioning was the opportunity to suckle, rather than the simultaneous presence of milk. Finally, the aversion to milk observed in Experiment 1 was shown to have resulted from long-delay learning, due to the ingestion of a sufficient dose of ethanol during testing to serve as an aversive unconditioned stimulus (Exp. 3).
多项研究证实，成年大鼠的饮食选择模式至少部分是由于早期接触哺乳期雌性大鼠乳汁中与食物相关的刺激而形成的（例如，卡普雷塔和罗尔斯，1974年；盖尔夫和克拉克，1972年；盖尔夫和亨德森，1972年）。本实验旨在研究断奶前的大鼠在哺乳环境中接触到这种线索后是否会同样改变它们对乙醇溶液的接受程度。在实验1中，给8日龄、12日龄和16日龄的大鼠经口投喂与牛奶混合的乙醇，同时让它们有机会吮吸麻醉的母鼠。随后的测试显示，12日龄和16日龄的受试大鼠相对于对照组而言，乙醇摄入量有所增加，而8日龄的大鼠则没有。最后，最年长（16日龄）的受试大鼠在条件反射形成和乙醇摄入测试24小时后接受测试时，也表现出对牛奶的条件性厌恶。实验2表明，乙醇条件反射的关键因素是吮吸的机会，而不是牛奶的同时存在。最后，实验3表明，实验1中观察到的对牛奶的厌恶是由于长时延迟学习导致的，因为在测试过程中摄入了足够剂量的乙醇，可作为一种厌恶的非条件刺激。
