Ackroff K, Sclafani A
Brooklyn College, City University of New York 11210.
Physiol Behav. 1994 May;55(5):957-62. doi: 10.1016/0031-9384(94)90086-8.
Prior studies have obtained strong conditioned preferences (> 90%) for flavors paired with intragastric (IG) infusions of Polycose (hydrolyzed starch) over different flavors paired with IG water infusions. These experiments used concentrated Polycose solutions (16-32%; 0.6-1.2 kcal/ml) that contributed 50% or more of the animals' daily caloric intake. The present experiment sought to determine if calorically dilute solutions would also support preference conditioning. Adult female rats with gastric cannulas were trained with a cue solution (the CS+) paired with Polycose infusions. On alternate days a different cue solution (the CS-) was paired with IG water infusions. The CSs were unsweetened or saccharin-sweetened citric acid and sucrose octaacetate solutions that were available 22 h/day; chow was freely available. Separate groups were infused with Polycose at concentrations of 0.5%, 1%, 2%, and 4% (0.019-0.152 kcal/ml). The three higher concentrations conditioned flavor preferences of up to 89%. The infused Polycose represented only 1-14% of the animals' daily caloric intake and did not reliably reduce chow consumption. These findings demonstrate the sensitivity of the viscerosensory feedback system mediating flavor conditioning.
先前的研究表明，与胃内（IG）输注聚葡萄糖（水解淀粉）配对的味道相比，与IG输注水配对的不同味道，能产生强烈的条件性偏好（>90%）。这些实验使用了浓缩的聚葡萄糖溶液（16 - 32%；0.6 - 1.2千卡/毫升），其提供了动物每日热量摄入的50%或更多。本实验旨在确定热量稀释的溶液是否也能支持偏好条件反射。对成年雌性大鼠进行胃插管，用与聚葡萄糖输注配对的提示溶液（CS +）进行训练。在交替的日子里，将不同的提示溶液（CS -）与IG输注水配对。CS是无糖或糖精调味的柠檬酸和蔗糖八乙酸酯溶液，每天提供22小时；可自由获取食物。将大鼠分为不同组，分别输注浓度为0.5%、1%、2%和4%（0.019 - 0.152千卡/毫升）的聚葡萄糖。三种较高浓度的溶液产生的味道偏好高达89%。输注的聚葡萄糖仅占动物每日热量摄入的1 - 14%，且并未可靠地减少食物摄入量。这些发现证明了介导味道条件反射的内脏感觉反馈系统的敏感性。
