Frank Guido K W, Oberndorfer Tyson A, Simmons Alan N, Paulus Martin P, Fudge Julie L, Yang Tony T, Kaye Walter H
University of Colorado at Denver and Health Sciences Center, Department of Psychiatry, The Children's Hospital, Aurora, CO 80045, USA.
Neuroimage. 2008 Feb 15;39(4):1559-69. doi: 10.1016/j.neuroimage.2007.10.061. Epub 2007 Nov 19.
Animal models suggest that sucrose activates taste afferents differently than non-caloric sweeteners. Little information exists how artificial sweeteners engage central taste pathways in the human brain. We assessed sucrose and sucralose taste pleasantness across a concentration gradient in 12 healthy control women and applied 10% sucrose and matched sucralose during functional magnet resonance imaging. The results indicate that (1) both sucrose and sucralose activate functionally connected primary taste pathways; (2) taste pleasantness predicts left insula response; (3) sucrose elicits a stronger brain response in the anterior insula, frontal operculum, striatum and anterior cingulate, compared to sucralose; (4) only sucrose, but not sucralose, stimulation engages dopaminergic midbrain areas in relation to the behavioral pleasantness response. Thus, brain response distinguishes the caloric from the non-caloric sweetener, although the conscious mind could not. This could have important implications on how effective artificial sweeteners are in their ability to substitute sugar intake.
动物模型表明，蔗糖激活味觉传入神经的方式与无热量甜味剂不同。关于人工甜味剂如何在人脑中参与中枢味觉通路的信息很少。我们评估了12名健康对照女性在不同浓度梯度下蔗糖和三氯蔗糖的味觉愉悦度，并在功能磁共振成像期间应用了10%的蔗糖和匹配的三氯蔗糖。结果表明：（1）蔗糖和三氯蔗糖均激活功能连接的初级味觉通路；（2）味觉愉悦度可预测左侧脑岛的反应；（3）与三氯蔗糖相比，蔗糖在前脑岛、额盖、纹状体和前扣带回中引发更强的脑反应；（4）仅蔗糖刺激而非三氯蔗糖刺激，与行为愉悦度反应相关的多巴胺能中脑区域参与其中。因此，尽管意识无法区分，但大脑反应能区分热量甜味剂和无热量甜味剂。这可能对人工甜味剂替代糖摄入的有效性具有重要意义。
