CIRCUMVENTRICULAR ORGANS--MODULATORS OF HOMEOSTASIS

穹隆下器(SFO)与脑室周围器官一样，位于 大脑的前部，以及位于大脑后部的最后区(AP) 大脑，缺乏血脑屏障，可能是中枢受体 影响行为和生理控制的体液因素的位置 动态平衡。每一个都有传出的神经投射，使它们能够 影响大脑功能。SFO主要影响视前丘脑 功能和AP主要影响上行内脏的继电器 传入信息。这笔赠款的第一个主要目标是 确定投射的神经成分的功能作用 SFO和AP在行为、神经内分泌和生理对照中的作用 水和盐的平衡。显微横切、微损伤和抽吸 损伤将被用来中断神经回路的特定元素 并将分析准备工作中的具体和一般赤字 行为和生理控制机制。这些准备工作将 被给予个人挑战，他们的饮酒反应被跟踪 监测尿量和血浆参数的短期和长期 以评估内部状态的变化。第二个主要目标是 继续神经解剖学研究SFO、AP、 和孤束核使用辣根的共轭化合物 过氧化物酶、荧光染料和氚氨基酸作为示踪剂。 将特别注意传入神经的大小和位置 SFO和AP的来源与规模和目的地的比较 他们传出的投射。这项研究将加深我们对 口渴和动态平衡的基本机制，并将提供见解 进入协调行为、神经内分泌和 自我平衡功能的自主控制。它专注于简单的路径， 高级前脑机制和低级脑干区之间的一些差异 接受直接的内脏传入输入。它强调的是行为 控制但不忽视生理机制，以避免错误 对行为变化的解释。这项多学科的研究 将更好地了解与健康相关的复杂问题，如 高血压、原发性高钠血症、不当综合征 抗利尿激素分泌和心因性多饮。

As circumventricular organs, the subfornical organ (SFO), situated at the front of the brain, and the area postrema (AP), located at the rear of the brain, lack a blood-brain barrier making them putative central receptor sites for humoral factors affecting behavioral and physiological controls of homeostasis. Each has efferent neural projections enabling them to affect brain function. The SFO primarily affects preoptichypothalamic function and the AP primarily affects relays for ascending visceral afferent information. The first major objective of this grant is to determine the functional roles of the neural components of the projections of the SFO and AP in behavioral, neuroendocrine and physiological controls of water and salt balance. Microtransections, microlesions and aspiration lesions will be used to interrupt specific elements of the neural circuitry and the preparations will be analyzed for specific and general deficits in behavioral and physiological control mechanisms. These preparations will be given individual challenges and their drinking responses followed over the short and long term while monitoring urine output and plasma parameters to assess alterations in internal state. The second major objective is to continue neuroanatomical studies of the neural connectivity of the SFO, AP, and the nucleus of the solitary tract using conjugates of horseradish peroxidase, fluorescent dyes and tritiated amino acids as tracers. Particular attention will be given to the size and location of the afferent sources to the SFO and AP in comparison to the size and destination of their efferent projections. This research will further our understanding of basic mechanisms of thirst and homeostasis and will provide insights into the neural circuitry coordinating behavioral, neuroendocrine and autonomic controls of homeostatic function. It focuses on simple pathways, some between higher forebrain mechanisms and lower brainstem areas receiving direct visceral afferent input. It emphasizes behavioral controls but does not neglect physiological mechanisms to avoid mistaken interpretations of behavioral changes. This multidisciplinary research will better enable understanding of complex health related problems such as hypertension, essential hypernatremia, syndrome of inappropriate antidiuretic hormone secretion and psychogenic polydipsia.