CIRCUMVENTRICULAR ORGANS--MODULATORS OF HOMEOSTASIS

穹窿下器（subfornicalorgan，SFO）是室周器官，位于室管膜下，位于室管膜下。 大脑前部和位于大脑后部的最后区（AP） 大脑，缺乏血脑屏障，使他们假定的中央受体 影响行为和生理控制的体液因素的位点 体内平衡的原理 每个人都有传出神经投射， 影响大脑功能 SFO主要影响前视丘后丘脑 功能和AP主要影响中继上升内脏 传入信息 这项补助金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、神经内分泌和生理控制中的作用 水和盐的平衡。 微横断、微损伤和抽吸 损伤将用于中断神经回路的特定元件 并将分析制剂的具体和一般缺陷， 行为和生理控制机制。 这些准备工作将 接受个人挑战，然后他们的饮酒反应 在监测尿量和血浆参数的同时， 评估内部状态的变化。 第二个主要目标是 继续对SFO，AP， 和孤束核用辣根共轭物 过氧化物酶、荧光染料和氚化氨基酸作为示踪剂。 将特别注意传入神经的大小和位置 与SFO和AP的大小和目的地相比， 它们的传出投射 这项研究将进一步加深我们对 口渴和体内平衡的基本机制， 进入协调行为、神经内分泌和 自我平衡功能的自主控制。 它专注于简单的途径， 一些在高级前脑机制和低级脑干区域之间 接受直接内脏传入输入。 它强调行为 控制但不忽视生理机制，以避免错误 行为变化的解释。 这项多学科的研究 更好地理解复杂的健康相关问题， 高血压，原发性高钠血症，不恰当综合征 抗利尿激素分泌和心因性烦渴。

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.