Program in Behavioral Neuroscience, Department of Psychology, The State University of New York, University at Buffalo, Buffalo, NY 14260, USA.
Program in Neuroscience, Department of Psychology, Florida State University, Tallahassee, FL 32306, USA.
Chem Senses. 2021 Jan 1;46. doi: 10.1093/chemse/bjab036.
Outbred rats differ in their preference for the artificial sweetener sucralose. Psychophysical assessments have shown that the taste of sucralose is differentially generalized to either sucrose or a sucrose-quinine (QHCl) mixture in sucralose preferers (SP) and sucralose avoiders (SA), respectively. It remains to be determined if these differences in the psychophysical assessment of the taste of sucralose are due to an insensitivity to any bitter-like taste component of sucralose in SP or reduced sensitivity to a sweet-like component in SA that may mask any putative aversive side-taste in SP. Here, we exploited the proposed chemotopic organization of the rostral nucleus of the solitary tract (rNTS) to further parse out the root differences in the perception of the salient taste qualities of sucralose using Fos-like immunoreactivity (FLI) to approximate neural activation following intraoral delivery of sucrose, QHCl, and sucralose solutions in previously categorized SA and SP. First, we confirmed previous reports that the medial third of the NTS is primarily responsive to intraoral infusions of the bitter taste stimulus QHCl while sucrose produces a more diffuse pattern of FLI. Upon comparing the FLI generated by intraoral sucralose, we found that the pattern in SA was indistinguishable from that of QHCl while SP displayed a pattern of FLI more representative of a sucrose-QHCl mixture. We conclude that SA, relative to SP, may be less sensitive to the sucrose-like properties of sucralose and that an enhanced sensitivity to these sucrose-like qualities may mask a QHCl-like quality in SP.
杂交大鼠对人工甜味剂三氯蔗糖的偏好存在差异。心理物理评估表明，三氯蔗糖的味道分别在三氯蔗糖偏好者（SP）和三氯蔗糖回避者（SA）中不同程度地泛化到蔗糖或蔗糖-奎宁（QHCl）混合物。目前尚不清楚对三氯蔗糖味道的心理物理评估中的这些差异是否是由于 SP 对三氯蔗糖的任何苦味成分不敏感，还是由于 SA 对甜味成分的敏感性降低，从而掩盖了 SP 中任何潜在的令人不快的副味。在这里，我们利用孤束核（rNTS）的假定化学拓扑组织，使用 Fos 样免疫反应（FLI）来进一步分析 SP 和 SA 对三氯蔗糖显著味道质量感知的根本差异，以近似于在先前分类的 SA 和 SP 中经口给予蔗糖、QHCl 和三氯蔗糖溶液后的神经激活。首先，我们证实了先前的报道，即 NTS 的中三分之一主要对口腔内的苦味刺激 QHCl 有反应，而蔗糖则产生更弥散的 FLI 模式。在比较口腔内三氯蔗糖产生的 FLI 时，我们发现 SA 的模式与 QHCl 无法区分，而 SP 则显示出更代表蔗糖-QHCl 混合物的 FLI 模式。我们得出结论，与 SP 相比，SA 可能对三氯蔗糖的蔗糖样性质的敏感性较低，而对这些蔗糖样性质的敏感性增强可能掩盖了 SP 中的 QHCl 样性质。
