SALT PREFERENCE IN RATS: INFLUENCE OF AGE AND STRAIN

本项目的长期目标是确定 导致盐偏好和摄入量的变化。 盐 偏好是指摄入钠或氯化钠 （NaCl）在没有生理需要的情况下， 因为高盐摄入量的兴趣已被牵连在 人类原发性高血压的发展和维持。 我们实验室以前的工作已经定义了这样的情况， 大鼠显示出与“物种典型标准”的显著偏离， 盐的偏好。 已经检查了两种大鼠模型，其中盐 偏好严重偏离了这一规范。 第一，幼鼠 - 可以被描述为一个盐暴食者，因为它不避免 浓度高达4%和6%的高渗NaCl溶液， 而成年大鼠完全可以避免这种情况。 另一个 一种被称为Fischer-344大鼠的近交系， 不喜欢NaCl溶液。 成年Fischer-344大鼠更喜欢 甚至等渗或低渗NaCl溶液与水混合。 这些 行为在盐偏好的连续体中处于极端。 虽然可能涉及许多因素，但 这一建议是假设，年龄和应变差异， 阿米洛利敏感的钠转运在测试芽有助于 这些大鼠对氯化钠的偏好差异很大。 味觉偏好的短期和长期行为研究 将被用来表征盐厌恶显示， Fischer-344大鼠以及检查其个体发育。 摄食 10天大的Long Evans大鼠对盐的行为将 也要检查。 行为和电生理方法 将被用来评估应变和年龄的假设 阿米洛利敏感性钠转运机制的差异 味蕾参与了对盐的厌恶 Fischer-344大鼠和高渗回避的出现 哺乳期的NaCl溶液 阿米洛利敏感性递送阿米洛利和测量舔 在用粘度计进行的简短访问测试中对NaCl溶液的行为， 电生理学研究检查多单位活动的 鼓索神经水或阿米洛利氯化钠溶液后 预处理

The long range goal of this project is to identify factors which contribute to variations in salt preference and intake. Salt preference refers to the ingestion of sodium or sodium chloride (NaCl) in the absence of physiological need and is of particular Interest because high salt Intake has been Implicated In the development and maintenance of essential hypertension in humans. Previous work in our laboratory has defined situations in which rats show significant departures from the "species typical norm" of salt preference. Two rat models have been examined where salt preference deviates sharply from this norm. One --the Infant rat- - could be characterized as a salt glutton, since it does not avoid hypertonic NaCl solutions at concentrations as high as 4% and 6%, which would be totally avoided by adult rats. The other --an inbred strain known as the Fischer-344 rat-- displays an unusual distaste for NaCl solutions. Adult Fischer-344 rats fall to prefer even isotonic or hypotonic NaCl solutions to water. These behaviors are at the extremes on a continuum of salt preference. Although a number of factors are likely to be involved, a focus of this proposal is the hypothesis that age and strain differences in amiloride-sensitive sodium transport at the tests bud contribute to the wide variations in NaCl preference displayed by these rats. Behavioral studies of taste preference in short and long term tests will be utilized to characterize the salt aversion displayed by Fischer-344 rats as well as examine its ontogeny. The ingestive behavior displayed by 10-day-old Long Evans rats toward salts will also be examined. Behavioral and electrophysiological approaches will be utilized to assess the hypothesis that strain and age differences in amiloride-sensitive sodium transport mechanisms at the taste bud are involved both in the aversion to salt displayed by Fischer-344 rats and in the emergence of avoidance of hypertonic NaCl solutions during the suckling period Behavioral studies of amiloride sensitivity delivery amiloride and measure licking behavior to NaCl solutions in brief access tests with a lickometer, electrophysiological studies examine multiunit activity of the chorda tympani nerve to NaCl solutions after water or amiloride pretreatment.