SALT PREFERENCE--INFLUENCE OF STRAIN AND AGE

描述：该项目的长期目标是确定因素 会导致摄取过量的钠或氯化钠 生理上的需要。盐偏好的决定因素包括 尤其令人感兴趣，因为高盐摄入量与 人类原发性高血压的发展和维持。在 大鼠对氯化钠的偏好随年龄和基因的变化而变化 特征，而这些变异与 味觉通路中的信号，特别是对阿米洛利敏感的信号 钠信号由鼓索神经传递。新生大鼠， 各种菌株，首选并自由摄取含有以下成分的溶液 极高浓度的氯化钠，以及它们的味觉神经 对氯化钠的敏感性相对较低。相比之下，费舍尔344 (F344)大鼠未能更喜欢氯化钠溶液而不是水，并在 其他菌株偏爱的浓度。F344大鼠表现出扩增的 神经对氯化钠刺激的反应和这种升高似乎是由于 完全达到更高的阿米洛利敏感性。当小路承载 这些信号被切断后，厌恶情绪消失，F344大鼠 表现出明显的对氯化钠的偏好。此外，最近发现的 接受CTX AS的成年大鼠对NH4Cl的异常偏好 新生儿让人想起自相矛盾的氯化铵偏好 新生儿，展示了发育中惊人的可塑性 味觉系统以及参与多重相互作用 小路。因此，本提案中的研究重点是确定 这些相互作用的性质及其使用修改的可能性 这些遗传和发育变异作为模型系统。研究将会 确定以下物质对舔食氯化钠的微观结构的影响： 劳损；需要状态；神经横断；以及增加和 减少味蕾对阿米洛利敏感的钠转运。研究 在新生时接受横切的成年大鼠将确定 他们对NH4Cl的反常偏好是否与 辨别氯化铵和氯化钠的能力减弱。更多的研究将 剩余的味觉神经的终末区域。更多的研究将 确定味觉通路的成熟与 使用一种评估技术对口味偏好的发展变化， 味觉反应性，可以通过广泛的常用方法来应用 年龄范围。

DESCRIPTION: The long range goal of this project is to identify factors which contribute to the ingestion of sodium or NaCl in excess of physiological need. The determinants of salt preference are of particular interest because high salt intake has been implicated in the development and maintenance of essential hypertension in humans. In the rat NaCl preference varies as a function of age and genetic characteristics, and these variations are associated with differences in signaling in gustatory pathways, in particular, amiloride-sensitive sodium signals conveyed by the chorda tympani nerve. Neonatal rats, of a variety of strains, prefer and freely ingest solutions containing remarkably high concentrations of NaCl, and their gustatory neural sensitivity to NaCl is relatively low. In contrast, the Fisher 344 (F344) rat fails to prefer NaCl solutions to water and avoids them at concentrations preferred by other strains. F344 rats show an amplified neural response to NaCl stimulation and this elevation appears to be due entirely to greater amiloride sensitivity. When the pathway carrying these signals is transected, the aversion disappears and F344 rats display a clear preference for NaCl. In addition, the recent finding of an anomalous preference for NH4Cl in adult rats which received CTX as neonates is reminiscent of the paradoxical NH4Cl preference of neonates, demonstrating the striking plasticity of the developing gustatory system as well as the involvement of multiple interacting pathways. Thus the studies in this proposal focus on determining the nature of these interactions and their potential for modification using these genetic and developmental variants as model systems. Studies will determine the effect on the microstructure of licking for NaCl of: strain; need state; nerve transection; and treatments which increase and decrease amiloride-sensitive sodium transport in taste buds. Studies of adult rats which received transections as neonates will determine whether their anomalous preference for NH4Cl is associated with an impaired ability to discriminate NH4Cl from NaCl. Additional studies will terminal fields of remaining gustatory nerves. Additional studies will define the relationship between maturation of gustatory pathways and developmental changes in taste preference using an assessment technique, taste reactivity, which can be applied with common methods across a wide range of ages.