NICOTINE REGULATION OF DEVELOPING BRAIN CATECHOLAMINES

尼古丁对发育中大脑儿茶酚胺的调节

• 批准号: 2700914
• 负责人: FRANCES M. LESLIE
• 金额: $ 17.82万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-05-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2700914
• 关键词: age difference; brain mapping; catecholamines; developmental genetics; developmental neurobiology; dopamine; embryo /fetus toxicology; in situ hybridization; laboratory rat; locus coeruleus; messenger RNA; neurochemistry; neurotransmitter transport; nicotine; nicotinic receptors; norepinephrine; radiotracer; receptor binding; receptor expression; substantia nigra; tissue /cell culture; tyrosine 3 monooxygenase

DESCRIPTION: (Applicant's Abstract) With recent data indicating an increased incidence of cigarette use among young women, the potential consequences of maternal smoking on fetal outcome is an issue of increasing clinical significance. In vivo data indicate that prenatal nicotine exposure has significant effects on the development of brain catecholamine (CA) systems, and that this may underlie some observed behavioral deficits. However, the exact mechanism by which nicotine affects central CA development is unclear. The purpose of the present application is to determine whether brain CA neurons are directly regulated by nicotinic receptors (nAChRS) during early brain development. Unlike the majority of previous studies, we propose to use in vitro methodologies so that experimental variables can be better controlled and indirect effects minimized. Quantitative anatomical techniques will be used to examine the developmental expression of nAChR mRNA and high affinity binding sites within developing norepinephrine (NE) and dopamine (DA) cells of the locus coeruleus (LC) and substantia nigra/ventral tegmental area (SN/VTA), respectively. Combined isotopic and non-isotopic in situ hybridization will be used to quantitate the developmental expression of nAChR subunit mRNAs within cells which also express the CA synthetic enzyme, tyrosine hydroxylase. High affinity nAChR binding in these developing cell groups will also be examined using [3H]cytisine and [3H]epibatidine as radioligands. Animals to be used for the study will be analyzed by age and sex, and will encompass the full range of CA development from embryonic day 15 through adult. The functional role of nAChRs in controlling NE and DA release in developing brain will be evaluated using transmitter release assays. Using brain slices, the effects of nicotine will be examined on NE and DA release from selected terminal fields of the LC and SN/VTA. The age of onset of nAChR regulation will be examined, as will the pharmacological characteristics of the receptor in immature brain. In particular, we will evaluate the hypothesis that the properties of nAChRs regulating LC function change with age. A primary neuronal cell culture model will also be used to analyze the properties of nAChRs on developing LC neurons, and to examine the developmental consequences of chronic nAChR activation. It is anticipated that the proposed in vitro analysis will provide a substantial framework for interpreting data on the effects of chronic perinatal nicotine administration in vivo.

描述：(申请人摘要) 最近的数据表明吸烟的发生率在 年轻女性，母亲吸烟对胎儿结局的潜在后果 是一个越来越具有临床意义的问题。活体数据表明， 产前尼古丁暴露对糖尿病的发生有显著影响 脑儿茶酚胺(CA)系统，这可能是一些观察到的 行为缺陷。然而，尼古丁影响的确切机制 中央CA的发展尚不清楚。本申请的目的是 是确定大脑CA神经元是否受到尼古丁的直接调节 早期大脑发育过程中的受体(NAChRs)。与大多数人不同 在之前的研究中，我们建议使用体外方法 实验变量可以更好地控制和间接影响 最小化。将使用定量解剖学技术来检查 NAChR mRNA和高亲和力结合部位的发育性表达 在发育中的去甲肾上腺素(NE)和多巴胺(DA)细胞内 蓝斑(LC)和黑质/腹侧被盖区(SN/VTA)； 分别进行了分析。结合同位素和非同位素原位杂交将 用来定量检测nAChR亚单位mRNAs的发育表达 在也表达CA合成酶的细胞内，酪氨酸 羟基酶。这些发育中的细胞群中高亲和力的nAChR结合 也将使用[~3H]胞嘧啶和[~3H]表巴替丁作为 放射性配基。将用于这项研究的动物将按年龄和 性，并将涵盖从胚胎当天起CA发育的全部范围 15岁至成人。NAChRs在调控NE和DA中的作用 将使用递质释放来评估发育中的大脑的释放 化验。利用脑片，将研究尼古丁对去甲肾上腺素的影响 以及从LC和SN/VTA的选定终端字段释放DA。《时代》 将检查nAChR调节的起始时间，以及药理学 未成熟脑中受体的特征。特别是，我们将 评估nAChRs调节LC功能的性质的假说 随着年龄的增长而改变。原代神经元细胞培养模型也将用于 分析nAChRs在发育中的LC神经元上的特性，并检测 慢性nAChR激活的发育后果。它是 预计拟议的体外分析将提供实质性的 解释慢性围产期尼古丁影响数据的框架 体内给药。