Role of Olfaction in the Conditioned Sucrose Preference of Sweet-Ageusic T1R3 Knockout Mice
Role of Olfaction in the Conditioned Sucrose Preference of Sweet-Ageusic T1R3 Knockout Mice
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DOI：
10.1093/chemse/bjp055
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发表时间：
2009-10-01
期刊：
影响因子：
3.5
通讯作者：
Sclafani, Anthony
中科院分区：
文献类型：
--
作者：
Zukerman, Steven;Touzani, Khalid;Sclafani, Anthony
先前的工作表明，甜味缺陷的T1 R3敲除（KO）小鼠在长期糖与水测试时产生了显着的蔗糖偏好。本研究探讨了嗅觉在这种经验条件性蔗糖偏好中的作用。对T1 R3 KO和C57 BL/6野生型（WT）小鼠进行24小时糖与水试验，蔗糖浓度递增（0.5-32%），之后小鼠接受嗅球切除术（OBx）或假手术。当用蔗糖重新测试时，Sham-KO小鼠喜欢所有的糖溶液而不是水，尽管它们的摄入量和偏好低于Sham-WT小鼠。相比之下，OBx-KO小鼠对稀释的蔗糖溶液（0.5-8%）没有或表现出微弱的偏好，尽管它们强烈偏好浓缩的糖溶液（16-32%）。OBx-WT小鼠的蔗糖偏好仅部分降低。尽管两种基因型的OBx小鼠相对于Sham小鼠消耗稀释蔗糖溶液不足，但它们过度消耗浓缩蔗糖。这些结果表明，嗅觉在T1 R3 KO小鼠对稀糖溶液的条件偏好中起着关键作用。此外，OBx-KO小鼠在没有正常甜味和嗅觉感觉的情况下偏好浓缩蔗糖溶液的事实强调了口后营养信号在促进摄取方面的效力。
Prior work has shown that sweet taste-deficient T1R3 knockout (KO) mice developed significant sucrose preferences when given long-term sugar versus water tests. The current study investigated the role of olfaction in this experience-conditioned sucrose preference. T1R3 KO and C57BL/6 wild-type (WT) mice were given 24-h sugar versus water tests with ascending concentrations of sucrose (0.5-32%), after which the mice received olfactory bulbectomy (OBx) or sham surgery. When retested with sucrose, the Sham-KO mice preferred all sugar solutions to water, although their intake and preference were less than those of the Sham-WT mice. The OBx-KO mice, in contrast, showed no or weak preferences for dilute sucrose solutions (0.5-8%) although they strongly preferred concentrated sugar solutions (16-32%). OBx-WT mice displayed only a partial reduction in their sucrose preference. Although the OBx mice of both genotypes underconsumed dilute sucrose solutions relative to Sham mice, they overconsumed concentrated sucrose. These results indicate that olfaction plays a critical role in the conditioned preference of T1R3 KO mice for dilute sugar solutions. Further, the fact that OBx-KO mice preferred concentrated sucrose solutions in the absence of normal sweet taste and olfactory sensations underscores the potency of postoral nutritive signals in promoting ingestion.