Ueji Kayoko, Minematsu Yuji, Takeshita Daisuke, Yamamoto Takashi
Department of Health and Nutrition, Faculty of Health Science, Kio University, 4-2-4 Umami-naka, Koryo, Kitakatsuragi, Nara 635-0832, Japan and.
Health Science Research Center, Kio University, 4-2-4 Umami-naka, Koryo, Kitakatsuragi, Nara 635-0832, Japan.
Chem Senses. 2016 Feb;41(2):135-41. doi: 10.1093/chemse/bjv064. Epub 2015 Oct 28.
Innate and learned taste/flavor preferences to chemical stimuli in weanling rats are not fully understood. Our previous study showed that weanling rats could establish conditioned flavor preferences when low, but not high, concentrations of sucrose solutions were used as associative rewarding stimuli. Here, we examined whether 3-week-old rats could acquire flavor learning when the rewarding stimulus was saccharin, a non-nutritive artificial sweetener. In the acquisition session, they consumed water with a flavor (cherry or grape) and 0.1% sodium saccharin with another flavor (grape or cherry) for 15 min daily on alternative days over 6 consecutive days. The subsequent test session revealed significant preferences for the flavor previously associated with saccharin. However, they failed to retain the preference when retested in adulthood at the age of 20 weeks. These behavioral results were similar to those previously demonstrated when 2% sucrose was used as an associative sweetener. Although these 2 solutions were equally preferred, the taste quality may not be the same because the weanling rats showed neophobia to 0.1% saccharin and a larger chorda tympani response than 2% sucrose. The present study showed that a conditioned flavor preference was established to saccharin in weanling rats on the basis of flavor-taste association.
对断乳大鼠化学刺激的先天和习得味觉/风味偏好尚未完全了解。我们之前的研究表明，当低浓度而非高浓度蔗糖溶液用作联想奖励刺激时，断乳大鼠能够建立条件性风味偏好。在此，我们研究了3周龄大鼠在奖励刺激为糖精（一种无营养人工甜味剂）时是否能够获得风味学习。在习得阶段，它们在连续6天的交替日中，每天饮用15分钟带有一种风味（樱桃或葡萄）的水和带有另一种风味（葡萄或樱桃）的0.1%糖精钠溶液。随后的测试阶段显示，它们对先前与糖精相关的风味有显著偏好。然而，当在20周龄成年期重新测试时，它们未能保持这种偏好。这些行为结果与之前使用2%蔗糖作为联想甜味剂时所证明的结果相似。尽管这两种溶液同样受偏爱，但味觉质量可能不同，因为断乳大鼠对0.1%糖精表现出新异恐惧，且鼓索神经反应比2%蔗糖更大。本研究表明，断乳大鼠基于风味-味觉关联对糖精建立了条件性风味偏好。
