BRAIN MONOAMINES AND LUTEINIZING HORMONE SECRETION

这项研究计划的总体目标一直是确定和 描述荷尔蒙(LH)和催乳素(PRL)的作用 脑下垂体前叶对中枢神经递质和 调节黄体生成素分泌的神经肽系统 生理刺激。神经肽Y(NPY)在该系统中的作用如下 由肾上腺素能递质提供的信号的放大器，以 刺激促黄体生成素释放激素(LHRH)的分泌，并增加 LHRH提供给促性腺激素的信号。在此应用程序中，我们 建议将这项研究扩展到新的生理学背景下， 继最近证明NPY的合成在 内侧-基础下丘脑在哺乳期上调，而且至少 这在一定程度上是由于这种多肽在 结节漏斗多巴胺(TIDA)神经元。目前，无论是 生物学意义，也不是唤起的生理信号， NPY的这种状态特定的改变表达是已知的，并且建议的 研究旨在解决这两个问题。因为美国反兴奋剂机构 系统是主要的神经内分泌PRL抑制系统，我们假设 下丘脑内侧基底核NPY的增加可能 影响垂体前叶催乳素分泌的机制 DA对乳酸菌的作用和/或DA的释放 下丘脑。第二，我们将审查是否压制 哺乳期间由哺乳产生的促性腺激素分泌 刺激和PRL升高是由NPY的增加通过 与内源性阿片类药物的相互作用。作为第三个主要目标，我们将 检查催乳素和/或哺乳刺激是否为生理信号 这导致下丘脑内侧-基底核NPY表达增加 在哺乳期间。第一个具体目标包括体外研究， 将研究NPY和NPY-DA相互作用对Second的影响 培养的垂体前叶细胞的信使系统和催乳素分泌。 第二个具体目标将使用体外和体内方法来 研究神经肽Y是否调节正中隆起DA的释放 哺乳期的老鼠。对第三个特定目标的体内研究将 确定DA和NPY在癫痫发作模式产生中的作用 哺乳期PRL分泌及NPY、DA变化规律的研究 在护理过程中释放。第四个具体目标将调查 NPY-内源性阿片类药物相互作用介导抑制 用体内效应检测哺乳期促性腺激素的分泌 NPY和NPY拮抗剂，并通过检查NPY与阿片类药物的相互作用，在 哺乳期大鼠黄体生成素分泌和LHRH受体调节。 这些研究还将探讨NPY对LHRH和LHRH的体外影响 哺乳期大鼠下丘脑内侧-基底区β-内啡肽的释放。 第五个具体目标将评估哺乳刺激和/或 催乳素的一个中心作用是负责 大鼠下丘脑内侧基底核NPY表达增强 哺乳。这些研究将测试生产的效果 非哺乳期大鼠高催乳素血症及对催乳素的抑制作用 哺乳期大鼠a)内侧基底核NPY免疫反应的释放 下丘脑(RIA)，b)NPY免疫反应和神经支配模式 在TIDA和非TIDA神经元中(通过光和EM免疫细胞化学)，以及 C)TIDA和非TIDA神经元中的前ProNPY mRNA水平(原位观察 杂交)。

The overall objective of this research program has been to identify and characterize the actions of hormone (LH) and prolactin (PRL) from the anterior pituitary gland in response to the central neurotransmitter and neuropeptide systems that regulate the secretion of luteinizing physiological stimuli. Neuropeptide Y (NPY) functions in this system as an amplifier of the signals provided by the adrenergic transmitters to stimulate LH-releasing hormone (LHRH) secretion and also augments the signal provided to the gonadotrophe by LHRH. In this application, we propose to extend this research into a new physiological context, following the recent demonstrations that the synthesis of NPY in the medial-basal hypothalamus is up-regulated in lactation, and that at least part of this is attributable to a novel expression of the peptide in the tuberoinfundibular dopamine (TIDA) neurons. At present, neither the biological significance of, nor the physiological signals that evoke, this state-specific altered expression of NPY are known, and the proposed studies are designed to address these two questions. Because the ADA system is the major neuroendocrine PRL-inhibiting system, we hypothesize that the increased NPY present in the medial basal hypothalamus may affect PRL secretion from the anterior pituitary gland by modulating the action of DA on the lactotrophes and/or the release of DA from the hypothalamus. Second, we will examine whether the suppression of gonadotropin secretion during lactation that is produced by the suckling stimulus and elevated PRL is mediated by the increased NPY via an interaction with endogenous opioids. As the third main objective, we will test whether PRL and/or the suckling stimulus is the physiological signal that leads to increased NPY expression in the medial-basal hypothalamus during lactation. The first Specific Aim contains in vitro studies that will investigate the effects of NPY and NPY-DA interactions on second messenger systems and PRL secretion in cultured anterior pituitary cells. The second Specific Aim will use in vitro and in vivo approaches to examine whether NPY modulates the release of DA from the median eminence of lactating rats. In vivo studies of the third Specific Aim will determine the roles of DA and NPY in generating the episodic pattern of PRL secretion during lactation and measure the pattern of NPY and DA release during nursing. The fourth Specific Aim will investigate whether an NPY-endogenous opioid interaction mediates the inhibition of gonadotropin secretion during lactation by testing the in vivo effects of NPY and NPY antagonists, and by examining NPY-opioid interaction, in episodic LH secretion and LHRH receptor regulation in lactating rats. These studies will also investigate in vitro effects of NPY on LHRH and Beta-endorphin release from medial-basal hypothalamus of lactating rats. The fifth Specific Aim will evaluate whether the suckling stimulus and/or a central action of PRL is the physiological signal responsible for enhanced NPY expression in the medial basal hypothalamus during lactation. These studies will test the effects of producing hyperprolactinemia in non-lactating rats and of suppression of PRL release in lactating rats on a) NPY immunoreactivity in the medial basal hypothalamus (by RIA), b) NPY immunoreactivity and innervation pattern in TIDA and non-TIDA neurons (by light and EM immunocytochemistry), and c) preproNPY mRNA levels in TIDA and non-TIDA neurons (by in situ hybridization).