SALT PREFERENCE--INFLUENCE OF STRAIN AND AGE

描述：本项目的长期目标是确定 这有助于摄入过量的钠或NaCl， 生理需要。 盐偏好的决定因素是 特别令人感兴趣的是，高盐摄入量与 人类原发性高血压的发展和维持。在 大鼠的NaCl偏好随着年龄和遗传而变化 特征，这些变化与以下方面的差异有关 味觉通路中的信号传导，特别是阿米洛利敏感的 由鼓索神经传递的钠信号。 新生大鼠， 各种菌株，喜欢并自由摄取含有 非常高浓度的NaCl，它们的味觉神经 对NaCl的敏感性相对较低。Fisher 344 （F344）大鼠不喜欢NaCl溶液而不喜欢水， 其他菌株更喜欢的浓度。F344大鼠表现出放大的 对NaCl刺激的神经反应，这种升高似乎是由于 阿米洛利的敏感性更高。当这条通道 这些信号被切断，厌恶消失，F344大鼠 对NaCl有明显的偏好此外，最近发现， 在接受CTX的成年大鼠中， 新生儿是令人想起矛盾的NH 4Cl偏好， 新生儿，表现出惊人的可塑性的发展 味觉系统以及参与多个相互作用 途径。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 这些遗传和发育变异作为模型系统。研究将 确定以下物质对NaCl舔体微观结构的影响： 紧张;需要状态;神经切断;和治疗， 降低味蕾中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的数量将确定 他们对NH 4Cl的异常偏好是否与 区分NH 4Cl和NaCl的能力受损。其他研究将 剩余味觉神经的末端区域。其他研究将 定义味觉通路成熟与 使用评估技术的味觉偏好的发育变化， 味觉反应性，其可以用常见方法应用于广泛的 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.