ELECTROPHYSIOLOGICAL CORRELATES OF VASOPRESSIN RELEASE

该项目的长期目标是促进 了解的功能和形态组织的 下丘脑-神经垂体系统，负责 加压素和催产素的分泌。 该系统 主要在体外使用视上神经垂体外植体进行研究 因为稳定的细胞内记录是可能的， 制备，并且由于膜性质和神经递质作用 更容易研究细胞外的控制水平 液 该项目将在很大程度上侧重于详细分析 在形态、膜性能等方面的异同 和神经递质的反应， 雄性和雌性大鼠视上核内的加压素神经元 如通过细胞内记录和填充， 免疫细胞化学鉴定 一般的假设是， 催产素和加压素神经元具有可区分的特征， 超越其肽能表型，这是其基础或促进其 在激素释放过程中表达特定放电模式的能力。 一些 差异可能是性别依赖性的，或者在女性中，选择性地表达 在哺乳期，赋予这些神经元一种功能性的 可塑性以适应激素分泌的需求。 该项目还 包括确定是否神经元在eh核周区的 视上核起中间神经元作用并提供抑制性突触 神经分泌神经元的输入。 建议的具体目标 研究期间：1）继续表征 电生理和形态学特征 催产素和加压素神经元，目的是了解为什么一些 属性是共享的，其他属性不在这两个类之间， 神经分泌细胞; 2）确定神经分泌细胞的机制， 神经调节剂组胺选择性地使膜去极化， 增强后叶加压素的去极化后电位，而不是催产素 3）确定GABA介导的神经元的性质和重要性 催产素和加压素神经元上的突触活动。 加压素 这对确定所有哺乳动物的适当水分平衡非常重要， 包括人类在内，其控制功能障碍导致许多病理性 条件，如尿崩症和慢性高钠血症。 一个 对控制催产素神经元活动的机制的理解是 重要的是要了解这种激素的作用，在女性 哺乳和劳动，以及其在男性中的不理解。

The broad, long-term objective of this project is to advance understanding of the functional and morphological organization of the hypothalamo-neurohypophysial system, which is responsible for the secretion of the hormones vasopressin and oxytocin. The system is studied primarily in vitro using a supraoptico-neurohypophysial explant from rats because stable intracellular recording are possible in this preparation, and because membrane properties and neurotransmitter actions are more easily studied with level of control over the extracellular fluid. This project will focus in large part on a detailed analysis of the similarities and differences in the morphology, membrane properties and neurotransmitter responsiveness of identified oxytocin and vasopressin neurons within the supraoptic nucleus in male and female rats as determined from intracellular recording and filling followed by immunocytochemical identification. The general hypothesis is that oxytocin and vasopressin neurons have distinguishable characteristics beyond their peptidergic phenotype, which underlie or facilitate their ability to express specific firing patterns during hormone release. Some differences may be sex-dependent, or in females, expressed selectively during the state of lactation, endowing these neurons with a functional plasticity to fit the demands of hormone secretion. The project also involves determining whether neurons in eh perinuclear zone of the supraoptic nucleus behave as interneurons and provide inhibitory synaptic inputs to neurosecretory neurons. The specific aims for the proposed research period are: 1) To continue the characterization of electrophysiological and morphological characteristics of identified oxytocin and vasopressin neurons, with the goal of understanding why some properties are shared and others are not between these two classes of neurosecretory cell; 2) To determine the mechanism by which the neuromodulator histamine selectively depolarizes the membrane and enhances the depolarizing afterpotential in vasopressin, but not oxytocin neurons; 3) To determine the nature and importance of GABA-mediated synaptic activity on oxytocin and vasopressin neurons. Vasopressin is very important in determining proper water balance in all mammals, including man, and dysfunctions in its control lead to many pathological conditions, such as diabetes insipidus and chronic hypernatremia. An understanding of the mechanisms controlling oxytocin neuron activity are important to the understanding of this hormone;s role in females during lactation and labor, and to its ill-understood in males.