Neuroendocrine Regulation of Biological Timing

生物时间的神经内分泌调节

• 批准号: 6528667
• 负责人: BRIAN J PRENDERGAST
• 金额: $ 4.81万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6528667
• 关键词: Peromyscus; behavioral /social science research tag; biological clocks; bioperiodicity; circadian rhythms; gonadotropin releasing factor; hormone regulation /control mechanism; hypothalamus; immunocytochemistry; in situ hybridization; neuroendocrine system; neuroimmunomodulation; neurons; neuroregulation; seasons; sex behavior

DESCRIPTION (provided by applicant): The goal of the proposed research is to evaluate neuroendocrine mechanisms that coordinate seasonal reproduction in deer mice (Peromyscus maniculatus). Individuals of this long-day breeding species display reproductive involution in short days, followed by photorefractoriness and spontaneous gonadal recrudescence, the onset of which is regulated by an endogenous interval timer (IT). Whereas many studies have addressed factors mediating autumnal regression, little is known about neuroendocrine changes that permit accurate timing of photorefractoriness. These studies assess the functional significance of biological clocks by testing whether latitudinal differences in the onset of vernal breeding are associated with differences in the period of the IT in wild rodents. Deer mice will be housed in winter photoperiods to trigger reproductive regression. The timing of refractoriness will be compared between groups of mice derived from different northern latitudes. Follow-up experiments will specify the relevant photoperiodic experiences that determine the duration of the IT, whether the IT has a heritable genetic basis, and the response of the IT to artificial selection. A related set of experiments will address the physiological bases of photorefractoriness. Immunocytochemical techniques will be used to quantify the number, size, and density of GnRH-immunoreactive neurons after photorefractoriness has been triggered in short days, and patterns of GnRH mRNA expression will be compared between photorefractory and photoresponsive individuals via in situ hybridization. Experiments will determine whether changes in subpopulations of hypothalamic GnRH neurons mediate photorefractoriness, or alternatively whether photorefractoriness is a sequence of changes in pituitary responsiveness to GnRH. These studies will combine ecological and molecular techniques to assess neuroendocrine mechanisms governing reproductive variation and seasonal timekeeping.

描述（由申请人提供）：拟议研究的目的是 评估协调季节性繁殖的神经内分泌机制 鹿小鼠（peromyscus maniculatus）。这个长期繁殖的人 物种在短时间内表现出生殖交往，其次是 光屈光度和自发性性腺复发性，其发作的发作 由内源性间隔计时器（IT）调节。而许多研究有 解决了介导秋季回归的因素，对 神经内分泌的变化，可以准确地光浪费性。 这些研究通过 测试春季繁殖发作的纬度差异是否是 与野生啮齿动物中IT期间的差异有关。鹿小鼠 将在冬季光周期中构成以触发生殖回归。这 将比较磨性的时机 不同的北部纬度。后续实验将指定相关的 确定IT持续时间的光周期体验，是否是IT 具有可遗传的遗传基础，以及IT对人造的反应 选择。一组相关的实验将解决 光致富。免疫细胞化学技术将用于量化 GNRH-免疫反应性神经元的数量，大小和密度 光致富性在短时间内触发，gnRH mRNA的模式 将比较光致敬和光反应之间的表达 个人通过原位杂交。实验将确定是否 下丘脑GNRH神经元亚群的变化介导 光致硬膜或光浪漫度是否为序列 垂体对GNRH的反应性变化。这些研究将结合在一起 评估神经内分泌机制的生态和分子技术 管理生殖变化和季节性计时。