MELATONIN IN THE CNS--REGULATION OF BEHAVIORAL CYCLES

我研究的长期目标是了解 性行为的神经内分泌控制及其调节机制 全年的表达。 大多数哺乳动物，包括人类， 表达生理和行为的日周期和年周期 流程. 动物模型已被证明在研究 这些节律的神经和内分泌基础。 叙利亚仓鼠 （Mesocricetus auratus）已被广泛研究，因为其 年周期可以在实验室条件下进行实验操作 条件 日长（光周期）的增加和减少， 季节变化的特点驱使仓鼠每年 生殖刺激和抑制的周期。 这些周期是 反映在循环激素水平的波动， 在生殖器官形态和功能方面， 性和其他行为。 内分泌和行为反应 需要松果体及其夜间活动 荷尔蒙褪黑激素的分泌。 人们对下列因素的影响知之甚多： 白天的长度对每晚褪黑激素信号的产生有影响，但 神经内分泌过程对褪黑激素作出反应， 生殖潜力还不太清楚。 褪黑激素结合位点 在中枢神经系统中的特征是 并且它们的位置已经通过体外放射自显影术使用 I-褪黑素作为配体。 褪黑激素结合位点已被发现， 大脑中有许多区域，但人们对这些区域知之甚少。 一个或多个位点与介导褪黑激素在脑组织中的作用有关。 日长信息的转换。 在此提出的实验 应用程序使用男性和女性，他们强调行为。 褪黑激素将使用以下方法给予切除松果体的仓鼠： 控制振幅、持续时间和时间的程序 褪黑素信号 一个独特的微透析输液系统将是 用于将褪黑激素递送到大脑的局部区域， 含有褪黑素结合位点。 这些站点响应的能力 褪黑激素和那里传递相关信息，以光周期 将对反应系统进行评估。 对雄性仓鼠的研究 研究光周期对行为和内分泌影响 系统，并将确定是否相同或不同的褪黑激素网站 都与每个人有关。 与女性个体相关性的研究 褪黑激素结合位点与每一种行为反应。 这些实验 不仅会大大扩展我们对季节性繁殖的认识 周期，但也将提供新的见解， 内外部变量及其对行为的调节 潜力

The long-term objective of my research is to understand the neuroendocrine control of sexual behavior and the mechanism that regulate its expression throughout the year. Most mammals, including humans, express daily and yearly cycles in physiological and behavioral processes. Animal models have proven extremely useful in studying the neural and endocrine bases of these rhythmics. The Syrian hamster (Mesocricetus auratus) has been extensively investigate because its annual cycles can be experimentally manipulated under laboratory conditions. Increases and decreases in day length (photoperiod) that are characteristic of the changing seasons drive the hamster through annual cycles of reproductive stimulation and inhibition. These cycles are reflected in fluctuating levels of circulating hormones, drastic changes in reproductive organ morphology and function, and altered potential for sexual and other behaviors. Both the endocrine and behavioral responses to changing day lengths require the pineal gland and its nocturnal secretion of the hormone, melatonin. Much is known about the effect of day length on the generation of the melatonin signal each night, but the neuroendocrine processes that respond to melatonin and result in altered reproductive potential are not well understood. Melatonin binding sites in the central nervous system have been characterized pharmacologically and their location has been determined by in vitro autoradiography using I-melatonin as ligand. Melatonin binding sites have been found in numerous areas throughout the brain, yet very little is known about which site or sites are relevant for mediating the effects of melatonin in the transduction of day length information. The experiments proposed in this application use both males and females, and they emphasize behavior. Melatonin will be administered to pinealectomized hamsters using procedures that control the amplitude, duration, and timing of the melatonin signal. A unique microdialysis infusion system will be employed to deliver melatonin into localized regions of the brain that contain melatonin binding sites. The capacity for these site to respond to melatonin and there by convey relevant information to photoperiodic response systems will be evaluated. Studies with the male hamster will investigate photoperiodic influence on both behavioral and endocrine system and will determine whether the same or different melatonin sites are relevant to each. Studies with the female relevance of individual melatonin binding sites to each behavioral response. These experiments will not only greatly expand our knowledge of seasonal reproductive cycles, but will also provide new insights into the interaction of internal and external variables and their regulation of behavioral potential.