MODEL FOR SENSITIVE PERIODS IN EARLY FLAVOR LEARNING

描述（由申请人提供）：人类的口味和食物偏好是在童年和青少年时期建立起来的，这一发现对长期健康具有重要意义。然而，这种偏好是如何形成的仍然是个谜。我们研究项目的主要目标是了解口味和食物偏好是如何发展的，并随着经验而改变。为此，我们调查了最早的风味体验，那些发生在子宫内和母乳喂养期间的体验，并证明这些体验会影响婴儿对各种风味和食物（包括蔬菜）的接受程度。最近，我们利用商业婴儿配方奶粉之间的显著风味差异作为模型，研究配方奶粉喂养婴儿早期经历的影响。在接受基于蛋白质水解物的配方奶粉方面的巨大发育变化，以及发现早期暴露导致对这种配方奶粉风味的享乐语气从绝对厌恶到渴望接受的完全转变，使其成为一个强大的实验工具。早期接触的影响尤其持久，导致孩子在最后一次接触几年后偏好发生改变。这些研究的结果为提出的关于确定风味和食物偏好的敏感期（“风味印记”）的调查奠定了基础。为了最大限度地发挥本研究的价值，大多数拟议的研究都是在同一组婴儿中进行的。这些婴儿将在他们生命的前三年进行研究，我们认为这一时期对建立长期的风味和食物接受模式至关重要。这个新颖的多学科研究项目的结果将对理解人类婴儿的感官引导反应和食物选择的生物学具有理论和实践意义。他们还将提供关于克服向临床需要的婴儿介绍水解配方奶粉的困难的战略的信息。参与每项拟议研究的儿童将根据最近发现的味觉受体基因进行基因分型，以确定基因差异如何影响食物偏好的发展。关于食物偏好形成机制的新知识，以及儿童（这一代人将与肥胖和糖尿病作斗争）喜欢和不喜欢食物的分子基础，可能为克服饮食引起的疾病提供策略。

DESCRIPTION (provided by applicant): Human flavor and food preferences established early in life track into childhood and adolescence, a finding with important implications for long-term health. How such preferences develop remains a mystery, however. The primary goal of our research program is to understand how flavor and food preferences develop and are modified with experience. To this end, we investigated the very earliest flavor experiences, those which occur in utero and during breastfeeding, and demonstrated that these experiences influence the infant's acceptance of a variety of flavors and foods including vegetables. More recently, we have taken advantage of the marked flavor differences among commercial infant formulas as a model to study the effects of early experiences in infants who are formula fed. The drastic developmental changes in acceptance of formulas which are protein hydrolysate based and the finding that early exposure results in a complete shift in hedonic tone to the flavor of this formula from one of absolute distaste to eager acceptance, make it a powerful experimental tool. The effects of early exposure were particularly persistent, leading to altered preferences several years after the child's last exposure. The findings from these studies set the stage for the proposed investigation on sensitive periods in determining flavor and food preferences ("flavor imprinting"). To maximize the value of this research, most of the proposed studies are conducted with the same cohort of infants. These infants will be studied across their first three years of life, a period we believe is crucial to the establishment of long-term patterns of flavor and food acceptance. The results of this novel, multidisciplinary research program will have both theoretical and practical implications for understanding the sensory-guided responses of human infants and the biology of food choice. They will also provide information on strategies to overcome the difficulties in introducing hydrolysate formulas to infants who need them clinically. Children participating in each of the proposed studies will be genotyped for recently discovered taste receptor genes to determine how genetic differences contribute to the development of food preferences. New knowledge about the mechanisms underlying the formation of food preferences and the molecular basis of food likes and dislikes in children, a generation who will struggle with obesity and diabetes, may suggest strategies to overcome diet-induced diseases.