NEURAL PATHWAYS FROM PHOTORECEPTORS TO THE PITUITARY

从光感受器到垂体的神经通路

• 批准号: 3312069
• 负责人: GARY L JACKSON
• 金额: $ 15.57万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-08-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3312069
• 关键词: bioperiodicity; central neural pathway /tract; circadian rhythms; controlled environment; controlled environment chamber; drug delivery systems; estradiol; estrus; experimental brain lesion; follicle stimulating hormone; hormone regulation /control mechanism; hypothalamus; implant; luteinizing hormone; melatonin; neural information processing; neuroendocrine system; olfactory lobe; ovariectomy; photobiology; progesterone; prolactin; radioimmunoassay; seasons; sheep; statistics /biometry; stereotaxic techniques; suprachiasmatic nucleus

The overall specific aims are to define the photoperiod conditions which permit expression of endogenous circannual rhythms of reproductive activity (anestrus versus estrous cycles as defined by blood progesterone) and prolactin secretion and to define the neural structures involved in generation and control of these rhythms using the sheep as the experimental model. Specific aims are: 1. To complete a study in progress testing the hypothesis that endogenous rhythms of reproductive activity in sheep are expressed only under certain constant photoperiods. Expression of circannual rhythms of reproductive activity and prolactin secretion will be compared in ewes housed under 12L:12D versus 8L:16D photoperiods. 2. To test the hypothesis that the effect of a specific signal (photoperiod regimen) on expression of endogenous circannual rhythms depends on the stage of the annual rhythm at which that signal is applied. Ewes will be placed under 12L:12D at 4 distinct stages of their annual cycle. Subsequent patterns of reproductive activity and prolactin secretion will be monitored. 3. To test the hypothesis that expression of an endogenous rhythm of reproductive activity is masked in ovary-intact ewes kept under a 12L:12D photoperiod. Comparison will be made of temporal changes in onset and cessation of estrous cycles in intact ewes versus changes of LH in ovariectomized estrogen-treated ewes housed under 12L:12D and 8L:16D photoperiods. 4. To test the null hypothesis that removal of the olfactory bulbs will not affect the ability of photoperiod changes to alter LH and prolactin secretion in ewes. The effect of olfactory bulbectomy on basal secretion of LH and FSH and on responses of these hormones to changes in photoperiod will be monitored. 5. To test the null hypotheses that lesions of the suprachiasmatic nucleus (SCN), lesions of the anterior hypothalamic area (AHA), or olfactory bulbectomy will not affect expression of circannual rhythms of reproductive activity and prolactin secretion in ewes kept under a constant photoperiod. In 3 separate experiments ewes will be subjected to either SCN lesions, AHA lesions, olfactory bulbectomy, or sham surgery and then housed under 8L:16D to determine if expression of the putative endogenous rhythm is altered.

总的具体目标是定义光周期条件， 允许表达生殖活动的内源性年周期节律 （乏情期与发情周期，由血孕酮定义）和 催乳素分泌，并确定参与的神经结构 以绵羊为实验动物， 模型 具体目标是： 1.完成一项正在进行的研究， 绵羊生殖活动的节律只有在一定的 恒定光周期 生殖周期节律的表达 活动和催乳素分泌将比较母羊圈养在 12L：12D对比8L：16D光周期。 2.为了检验特定信号（光周期）的影响 方案）对内源性昼夜节律表达的影响取决于 在该信号被应用时的年节律的阶段。 Ewes会 在12L：12D下，在其年周期的4个不同阶段。 随后的生殖活动和催乳素分泌模式将 被监控。 3.为了验证这一假设，表达的内源性节奏， 在12 L：12 D条件下饲养的卵巢完整母羊中， 光周期 将比较发病时间的变化， 完整母羊发情周期的停止与LH的变化 去势雌激素处理母羊，饲养于12 L：12 D和8 L：16 D下 光周期 4.为了检验零假设，即切除嗅球不会 影响光周期变化改变LH和催乳素的能力 母羊的分泌物。 嗅球切除术对基础分泌的影响 以及这些激素对光周期变化的反应 将受到监控。 5.检验视交叉上核病变 (SCN)下丘脑前区（AHA）病变，或嗅觉 球切除术不会影响生殖细胞的昼夜节律表达， 活动和催乳素分泌的绵羊保持在恒定的光周期。 在3个单独的实验中，将对母羊进行SCN病变、AHA 病变，嗅球切除术或假手术，然后在8L：16D下饲养 以确定假定的内源性节律的表达是否改变。