Department of Psychology, California State University, Long Beach, CA, USA.
Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
Chem Senses. 2018 Feb 26;43(3):181-188. doi: 10.1093/chemse/bjy005.
The orosensory characteristics of a diet play a role in its acceptance and rejection. The current study was designed to investigate the gustatory components that contribute to the intake of a palatable, high-energy diet (HE; 45% calories from fat, 17% calories from sucrose). Here, rats were conditioned to avoid HE diet by pairings with i.p. injections of LiCl to induce visceral malaise. Subsequently, the degree of generalization was tested to an array of taste compounds using a brief-access lick procedure (10-s trials, 30-min sessions). Compared to NaCl-injected controls, LiCl-injected rats suppressed licking response to 100% linoleic acid and 20% intralipid, and to a lesser extent 17% sucrose. There was more variability in the lick responses to sucrose among the LiCl-injected rats. Rats that tended to suppress licking responses to sucrose generalized this response to glucose, fructose and Na-saccharin but not to Polycose. In contrast, LiCl-injected rats did not significantly suppress lick responses to water, NaCl, citric acid, or quinine compared to controls rats. The brief access feature of this procedure, allows for behavioral measures when postingestive factors are minimized. These findings support a role for gustatory cues in the detection of high fat/high sugar diets. Furthermore, it appears that the fat component is a more salient orosensory feature of the HE diet.
饮食的口感特征在其接受和拒绝中起着作用。本研究旨在探讨有助于摄入美味、高能量饮食（HE；45%的热量来自脂肪，17%的热量来自蔗糖）的味觉成分。在这里，通过与腹腔注射氯化锂配对，使大鼠对 HE 饮食产生回避条件反射，从而诱导内脏不适。随后，使用短暂接触舔舐程序（10 秒试验，30 分钟试验）对一系列味觉化合物进行了概括程度的测试。与注射 NaCl 的对照组相比，注射 LiCl 的大鼠抑制了对 100%亚油酸和 20%中链脂肪乳剂的舔舐反应，对 17%蔗糖的抑制程度较低。LiCl 注射组大鼠对蔗糖的舔舐反应存在更大的变异性。倾向于抑制对蔗糖舔舐反应的大鼠将这种反应泛化到葡萄糖、果糖和 Na-糖精，但不能泛化到聚果糖。相比之下，与对照组相比，LiCl 注射大鼠对水、NaCl、柠檬酸或奎宁的舔舐反应没有显著抑制。该程序的短暂访问功能允许在最小化餐后因素的情况下进行行为测量。这些发现支持味觉线索在检测高脂肪/高糖饮食中的作用。此外，脂肪成分似乎是 HE 饮食更显著的口感特征。
