MSG intake and preference in mice are influenced by prior testing experience
MSG intake and preference in mice are influenced by prior testing experience
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DOI：
10.1016/j.physbeh.2012.06.022
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发表时间：
2012-09-10
影响因子：
2.9
通讯作者：
Sclafani, Anthony
中科院分区：
文献类型：
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作者：
Ackroff, Karen;Weintraub, Rachel;Sclafani, Anthony
谷氨酸钠（MSG）是典型的鲜味物质，在许多食物中用作增味剂，但单独使用时往往只有微弱的吸引力。然而，随着经验的积累，老鼠会对味精溶液产生强烈的偏好。本实验探讨了对味精偏好的无差异变化的条件。对C57 BL/6 J小鼠进行了一系列为期2天的两瓶试验，其中用水与一系列递增的MSG浓度（0.1-450 mM）进行比较，以评估偏好和摄入量。幼稚小鼠对所有浓度都不敏感，但在强制暴露于300 mM味精的一瓶后，它们更喜欢大多数浓度，并消耗更多的味精。暴露于100 mM味精也增加了随后的味精偏好，但不是摄入量。使用其他营养液（8%蔗糖、8%多糖、8%酪蛋白水解物和等热量的3.5%大豆油乳剂）的经验也提高了随后的味精偏好和摄入量。多糖和蔗糖的经验几乎与味精的经验一样有效。然而，并不是所有的咸味溶液都有效; 0.8%三氯蔗糖和10 mM味精暴露不会改变随后的味精偏好。通过提供递增系列（0.1-100 mM）的另一种鲜味物质一磷酸肌苷（IMP）来测试暴露前效应的一般性;在强制暴露于300 mM味精后，最初的冷漠转变为偏好。总之，这些结果表明，口腔和口腔后效应的组合可能是经验效应的原因，味精本身是最有效的刺激。最后一个实验表明，将味精和饮水嘴分开而不是并排放置，会增强未接触过的小鼠对味精的偏好。因此，小鼠对鲜味溶液的偏好受到先前促味剂经验以及喷口位置的影响，当研究小鼠对味道溶液的接受度时，应考虑到这一点。(C)2012 Elsevier Inc. All rights reserved.
Monosodium glutamate (MSG), the prototypical umami substance, is used as a flavor enhancer in many foods, but when presented alone is often only weakly attractive. Yet with experience mice will develop strong preferences for MSG solution over water. The present experiments explored the conditions that change indifference to preference for MSG. C57BL/6J mice were given a series of 2-day two-bottle tests with water vs. an ascending series of MSG concentrations (0.1-450 mM) to assess preference and intake. Naive mice were indifferent to all concentrations, but following forced one-bottle exposure to 300 mM MSG they preferred most concentrations and consumed more MSG. Exposure to 100 mM MSG also increased subsequent MSG preference but not intake. Experience with other nutritive solutions (8% sucrose, 8% Polycose, 8% casein hydrolysate, and isocaloric 3.5% soybean oil emulsion) also enhanced subsequent MSG preference and intake. Polycose and sucrose experience were almost as effective as MSG experience. However, not all sapid solutions were effective; 0.8% sucralose and 10 mM MSG exposure did not alter subsequent MSG preference. The generality of the preexposure effect was tested by offering an ascending series (0.1-100 mM) of inosine monophosphate (IMP), another umami substance; initial indifference was converted to preference after forced exposure to 300 mM MSG. Together these results suggest that a combination of oral and post-oral effects may be responsible for the experience effect, with MSG itself the most potent stimulus. A final experiment revealed that MSG preference in naive mice is enhanced by presenting the MSG and water drinking spouts far apart rather than side by side. Thus the preferences for umami solutions in mice are subject to influence from prior tastant experience as well spout position, which should be taken into account when studying acceptance of taste solutions in mice. (C) 2012 Elsevier Inc. All rights reserved.