NEUROCHEMICAL INTERACTIONS AND OXYTOCIN NEURONS

这项研究的长期目标是了解神经 哺乳期间催产素释放的潜在机制。 的 本提案中的实验具体旨在确定 去甲肾上腺素和兴奋性氨基酸，如谷氨酸， 已鉴定的催产素神经元的电生理特性 用细胞内电流和电压钳记录哺乳期大鼠 在下丘脑-神经垂体外植体或急性分离的神经元中 从哺乳期的老鼠身上。 本提案结合了 兴奋性氨基酸作用的表征， 去甲肾上腺素与识别的记录神经元作为 催产素能的或血管加压素能的，使用免疫细胞化学或 免疫印迹技术。 这个项目的主要假设是， 去甲肾上腺素和兴奋性氨基酸相互作用， 泌乳期间催产素神经元的行为。 具体目标是 项目是：1）检查去甲肾上腺素和α-1的作用 激动剂对泌乳期催产素神经元膜特性的影响 雌性大鼠; 2）表征兴奋性氨基酸对 催产素神经元，特别是确定AMPA和NMDA 受体存在;和3）确定兴奋性受体的水平， 氨基酸和去甲肾上腺素协同作用于催产素神经元。 对于每一个目标，催产素神经元的放电模式的影响，以及 作为对特定膜电位特性和离子的影响， 渠道将得到解决。 此外，任何影响的相关性 催产素的释放将使用发射机调制的尖峰序列进行测试 来驱动电刺激从孤立的 神经叶 催产素的释放对所有哺乳动物的正常泌乳至关重要。 哺乳动物，但几乎没有什么是已知的具体膜 这些神经元在哺乳期间的特性。

The long-term objective of this research is to understand the neural mechanisms underlying the release of oxytocin during lactation. The experiments in the present proposal are aimed specifically at determining how norepinephrine and excitatory amino acids, such as glutamate, affect the electrophysiological characteristics of identified oxytocin neurons in the lactating rat using intracellular current and voltage clamp recordings in the hypothalamo-neurohypophysial explant or in acutely isolated neurons from the lactating rat. The present proposal combines the characterization of the actions of excitatory amino acids and norepinephrine with the identification of the recorded neurons as oxytocinergic or vasopressinergic using immunocytochemical or immunoblotting techniques. The broad hypothesis of this project is that norepinephrine and excitatory amino acids interact to shape the firing behavior of oxytocin neurons during lactation. The Specific Aims of this project are: 1) to examine the effects of norepinephrine and alpha-1 agonists on the membrane properties of oxytocin neurons in lactating female rats; 2) to characterize the action of excitatory amino acids on oxytocin neurons and in particular to identify whether both AMPA and NMDA receptors are present; and 3) to determine the level at which excitatory amino acids and norepinephrine act synergistically on oxytocin neurons. For each aim the effects on the firing pattern of oxytocin neurons as well as the effects on specific membrane potential characteristics and ion channels will be addressed. In addition, the relevance of any effects to oxytocin release will be tested using transmitter-modulated spike trains to drive the electrical stimulation of hormone release from isolated neural lobes. Oxytocin release is essential to normal lactation in all mammals, yet virtually nothing is known about the specific membrane properties of these neurons during lactation.