Department of Pharmacology, CINVESTAV, Laboratory of Neurobiology of Appetite, Mexico City 07360, Mexico.
Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Wilfrido Massieu, Mexico City 07738, México.
eNeuro. 2020 Oct 30;7(5). doi: 10.1523/ENEURO.0268-20.2020. Print 2020 Sep/Oct.
The intensity of sucrose (its perceived concentration) and its palatability (positive hedonic valence associated with ingestion) are two taste attributes that increase its attractiveness and overconsumption. Although both sensory attributes covary, in that increases in sucrose concentration leads to similar increases in its palatability, this covariation does not imply that they are part of the same process or whether they represent separate processes. Both these possibilities are considered in the literature. For this reason, we tested whether sucrose's perceived intensity could be separated from its hedonically positive palatability. To address this issue, rats were trained in a sucrose intensity task to report the perceived intensity of a range of sucrose concentrations before and after its palatability was changed using a conditioned taste aversion (CTA) protocol. We found that the subjects' performance remained essentially unchanged, although its palatability was changed from hedonically positive to negative. Overall, these data demonstrate that sucrose's perceived intensity and its positive palatability can be dissociated, meaning that changes of one taste attribute render the other mostly unaffected. Thus, the intensity attribute is sufficient to inform the perceptual judgments of sucrose's concentrations.
蔗糖的强度（感知浓度）及其美味性（与摄入相关的积极享乐效价）是两个增加其吸引力和过度消费的味觉属性。尽管这两个感官属性是相关的，即蔗糖浓度的增加会导致其美味性的相似增加，但这种相关性并不意味着它们是同一过程的一部分，或者它们是否代表不同的过程。文献中考虑了这两种可能性。出于这个原因，我们测试了蔗糖的感知强度是否可以与其享乐性的正面美味性分开。为了解决这个问题，我们在蔗糖强度任务中对老鼠进行了训练，让它们在味觉厌恶条件作用（CTA）协议改变蔗糖的美味性之前和之后报告一系列蔗糖浓度的感知强度。我们发现，尽管其美味性从享乐性正面变为负面，但实验对象的表现基本保持不变。总的来说，这些数据表明，蔗糖的感知强度和其正面美味性可以分离，这意味着一种味觉属性的变化使另一种属性基本不受影响。因此，强度属性足以告知对蔗糖浓度的感知判断。
