AMINO ACID AND PEPTIDERGIC CONTROL OF SUPRAOPTIC NEURONS

荷尔蒙后叶加压素和催产素，在 维持血容量和渗透压，并在不同的生殖 哺乳动物的功能是由大细胞神经内分泌分泌的 下丘脑-神经垂体系统(HNS)的细胞(MNC)。的目标是 这里提出的研究是为了研究一些受体介导的 控制电活动和分泌活动的机制 在胞体水平和轴突终末。特别是，这项研究是 集中于某些氨基酸和二肽的影响，包括 γ-氨基丁酸、谷氨酸、天冬氨酸、N-乙酰天冬氨酸(NAA)和 N-乙酰天冬氨酸(NAAG)，它可能是许多生物体内的神经递质 包括HNS在内的CNS地区。 为了实现这些目标，全电池电压和电流钳位 技术将被用来研究受体的性质 兴奋性和抑制性氨基酸，受体-离子通道的性质 偶联和这些假定的神经递质对整体的影响 跨国公司的电子活动。录音将从分离的 成年大鼠视上核和培养新生大鼠的单核细胞 视上神经元在感受器机制研究中的作用 下丘脑的细胞体。录音也将从孤立的 成人神经垂体轴突终末在轴突形成机制的研究 终点站。成年神经元和轴突终末将从正常 大鼠和荷尔蒙分泌增加了两倍的大鼠 生理刺激：哺乳和脱水。这些 电生理研究将与对其影响的研究相结合。 这些可能的神经递质可以控制分泌，还可以提供 对化合物如何在治疗上有好处的洞察 中风和癫痫，针对氨基酸介导的受体和 相关的离子通道，但与中枢神经系统中的其他主要靶点，可以 影响这一生理上重要的激素分泌系统。

The hormones vasopressin and oxytocin, which have crucial roles in maintenance of blood volume and osmolality and in various reproductive functions in mammals, are secreted by the magnocellular neuroendocrine cells (MNCs) of the hypothalamo-neurohypophysial system (HNS). The goal of the research proposed here is to investigate some of the receptor-mediated mechanisms that control electrical and secretory activities both at the level of the soma and at the axon terminal. In particular, the research is focussed upon the effects of certain amino acids and dipeptides, including gamma-aminobutyric acid, glutamate, aspartate, N-acetylaspartate (NAA), and N-acetylaspartatylglutamate (NAAG) which may be neurotransmitters in many areas of the CNS including the HNS. To achieve these objectives, whole-cell voltage and current clamp techniques will be used to investigate the nature of the receptors for excitatory and inhibitory amino acids, the nature of receptor-ion channel coupling and the effects of these putative neurotransmitters on the overall electrical activities of MNCs. Recording will be made from dissociated MNCs of the adult rat supraoptic nucleus and from cultured neonatal supraoptic neurons in studies of receptor mechanisms at the level of the cell body in the hypothalamus. Recordings will also be made from isolated axon terminals of the adult neurohypophysis to study mechanisms at the axon terminal. Adult neurons and axon terminals will be obtained from normal rats and from rats where hormone secretion is increased by two physiological stimuli: lactation and dehydration. These electrophysiological studies will be combined with studies on the effects of these putative neurotransmitters may control secretion and also provide insights into how compounds, which may be therapeutically beneficial in stroke and epilepsy, directed at amino acid-mediated receptors and associated ion channels, but with other prime target sites in the CNS, may affect this physiologically important hormone-secreting system.