Pittman David W.
The prevalence of obesity has provided a strong incentive to understand the motivation to consume high-fat foods. Taste palatability of high-fat food is cited as the primary influence in the over consumption of dietary fat (Drewnowski, 1997; Drewnowski and Greenwood, 1983; McCrory et al., 1999, 2000; Warwick and Schiffman, 1990) and there is a strong positive correlation between obesity and daily high-level intake of dietary fat (McCrory et al., 1999; Miller et al., 1990, 1994). Traditionally, the sensory perception of dietary fat during ingestion has been characterized in terms of textural and postingestive effects. Certainly, dietary fat contributes to the mouthfeel of food-stuffs and can act as a positive reinforcer through fatty acid receptors found in the digestive tract that stimulate pathways leading to the natural reward centers of the brain. However, across the last decade, accumulating evidence from both molecular and behavioral research has begun to challenge the traditional perspectives on dietary fat perception by introducing the concept of chemoreception of dietary fat within the oral cavity, specifically through the gustatory system, as providing immediate and selective signals during dietary fat consumption. Like humans, rodents demonstrate a robust preference for high-fat foods (Greenberg and Smith, 1996; Smith et al., 2000; Warwick and Synowski, 1999; Warwick et al., 1990) and represent the most typical animal model in which the reception, transduction, and neural signaling of the peripheral gustatory system has been explored. This chapter reviews the behavioral evidence supporting a role of the gustatory system in the chemoreception of fatty acids, the principle chemical component of dietary fat.
肥胖症的流行促使人们深入了解食用高脂肪食物的动机。高脂肪食物的味觉适口性被认为是膳食脂肪摄入过量的主要影响因素（德雷诺夫斯基，1997年；德雷诺夫斯基和格林伍德，1983年；麦克罗里等人，1999年、2000年；沃里克和希夫曼，1990年），而且肥胖与每日高水平的膳食脂肪摄入量之间存在很强的正相关关系（麦克罗里等人，1999年；米勒等人，1990年、1994年）。传统上，人们在摄入过程中对膳食脂肪的感官感知一直是根据质地和摄入后的影响来描述的。当然，膳食脂肪有助于食物的口感，并且可以通过消化道中发现的脂肪酸受体作为一种正向强化物，刺激通向大脑天然奖赏中枢的通路。然而，在过去十年中，分子和行为研究积累的证据开始挑战关于膳食脂肪感知的传统观点，引入了口腔内膳食脂肪化学感受的概念，特别是通过味觉系统，在膳食脂肪摄入过程中提供即时和选择性信号。与人类一样，啮齿动物对高脂肪食物表现出强烈的偏好（格林伯格和史密斯，1996年；史密斯等人，2000年；沃里克和西诺夫斯基，1999年；沃里克等人，1990年），并且是探索外周味觉系统的接收、转导和神经信号传导的最典型动物模型。本章回顾了支持味觉系统在脂肪酸化学感受中起作用的行为证据，脂肪酸是膳食脂肪的主要化学成分。
