DIFFERENCES IN CCK RELEASE AND FUNCTIONS

CCK 版本和功能的差异

• 批准号: 3402136
• 负责人: PAUL E MICEVYCH
• 金额: $ 16.17万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-07-01 至 1997-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3402136
• 关键词: animal puberty; autoradiography; cholecystokinin; developmental neurobiology; estrogens; forskolin; gender difference; gene expression; genetic regulation; hormone regulation /control mechanism; hypothalamus; in situ hybridization; inhibitor /antagonist; laboratory rat; limbic system; messenger RNA; neuroanatomy; neuroendocrine system; neuropeptide receptor; neurotransmitter receptor; neurotransmitter transport; phorbols; preoptic areas; protein structure function; receptor binding; sex behavior; steroid hormone; synapses; tetrodotoxin

The main objective of the present study is to characterize the estrogenic regulation of prepro-cholecystokinin (pCCK) messenger RNA (mRNA) in cells of the limbic-hypothalamic circuit. This interconnected circuit, which includes the medial preoptic nucleus (MPN) and the ventromedial nucleus of the hypothalamus (VMH), is implicated in the integration of sensory and hormonal cues that are involved in the CNS control of reproductive behavior. Estrogen stimulates the expression of pCCK mRNA and CCK peptide and reversibly decreases CCK receptor binding levels in the VMH. The effects of exogenous CCK on reproductive behavior are estrogen dependent and site-specific; in the VMH, CCK inhibits and in the MPN, CCK facilitates lordosis behavior. The proposed research is a systematic examination of estrogenic modulation of pCCK mRNA levels in the limbic- hypothalamic circuit. Initially, we will determine whether estrogen activation of preproCCK mRNA expression is differentially regulated in cells projecting to the MPN compared with those that project to the VMH. We hypothesize that estrogen acts trans-synaptically to regulate pCCK mRNA expression and we propose to study the mechanisms through which estrogen upregulates pCCK message and peptide in the CNS. Experiments will determine if pCCK mRNA levels are regulated by estrogen when electrical activity is disrupted (with local infusions of tetrodotoxin) or when protein synthesis is disrupted (with anisomycin implants). These experiments will test also whether elevating second messengers with phorbol ester and forskolin will augment estrogen induced pCCK mRNA levels. Morphological evidence will be obtained for estrogenic stimulation of early response genes in pCCK cells and whether this is a trans-synaptic effect of estrogen. In the MPN, exogenous CCK facilitates lordosis but the type and distribution of CCK receptors has not been determined. a CCK receptor autoradiography study will map and characterize the distribution of CCK binding sites in the medial preoptic area. This experiment will help elucidate the observed facilitatory effects of endogenous CCK in the MPN. CCK-B receptors are found in the VMH, and the use of a selective CCK-B receptor antagonist, will allow us to examine the role of endogenous CCK in the modulation of lordosis behavior. We have shown that pCCK levels, in adulthood, are determined by the gonadal steroid environment. The adult steroid pattern appears at puberty. The last experiments will characterize the effects of estrogen during pubertal development of the limbic-hypothalamic CCK circuit and correlate the changes in expression of pCCK mRNA with induction of lordosis behavior. Together the proposed research will enhance our understanding not only of the limbic-hypothalamic CCK circuit but also contribute to our understanding of mechanisms involved in gonadal steroid trans-synaptic regulation of CNS neurochemistry.

本研究的主要目的是表征雌激素 细胞中前胆囊收缩素 (pCCK) 信使 RNA (mRNA) 的调节 边缘系统-下丘脑回路。 这个互连电路， 包括内侧视前核（MPN）和腹内侧核 下丘脑 (VMH) 参与感觉统合 以及参与中枢神经系统生殖控制的激素信号 行为。 雌激素刺激 pCCK mRNA 和 CCK 的表达 肽并可逆地降低 VMH 中的 CCK 受体结合水平。 外源性CCK对生殖行为的影响是雌激素 依赖性和特定地点；在 VMH 中，CCK 抑制；在 MPN 中，CCK 抑制 促进脊柱前凸行为。 拟议的研究是一项系统的 检查边缘系统中 pCCK mRNA 水平的雌激素调节 下丘脑回路。 首先，我们将确定是否有雌激素 preproCCK mRNA 表达的激活在 投射到 MPN 的细胞与投射到 VMH 的细胞进行比较。 我们假设雌激素通过跨突触作用来调节 pCCK mRNA 表达，我们建议研究其机制 雌激素上调 CNS 中的 pCCK 信息和肽。 实验 将确定 pCCK mRNA 水平是否受雌激素调节 电活动被破坏（局部注射河豚毒素） 或者当蛋白质合成被破坏时（使用茴香霉素植入物）。 这些 实验还将测试是否可以用 佛波酯和毛喉素会增强雌激素诱导的 pCCK mRNA 水平。 将获得雌激素的形态学证据 pCCK 细胞中早期反应基因的刺激以及这是否是一个 雌激素的跨突触作用。 在 MPN 中，外源 CCK 促进 脊柱前凸，但 CCK 受体的类型和分布尚未明确 决定。 CCK 受体放射自显影研究将绘制和 表征内侧视前区 CCK 结合位点的分布 区域。 该实验将有助于阐明观察到的促进作用 MPN 中内源性 CCK 的影响。 CCK-B 受体存在于 VMH 和选择性 CCK-B 受体拮抗剂的使用将使我们能够 检查内源性 CCK 在脊柱前凸调节中的作用 行为。 我们已经证明，成年期的 pCCK 水平是由 通过性腺类固醇环境。 成人类固醇模式出现 在青春期。 最后的实验将表征以下效果 边缘-下丘脑 CCK 青春期发育过程中的雌激素 电路并将 pCCK mRNA 表达的变化与 诱导脊柱前凸行为。 拟议的研究将共同 不仅增强我们对边缘-下丘脑 CCK 回路的理解 也有助于我们理解所涉及的机制 中枢神经系统神经化学的性腺类固醇跨突触调节。