Sex Behavior, Phallic Development and Seasonality

描述(由申请人提供)：该项目旨在明确雄激素供应的极端、昼夜和季节节律如何影响哺乳动物生殖结构和行为的发育和随后的维持。模式物种是西伯利亚仓鼠，Photor us sungorus sungorus。雄性哺乳动物诱导和维持性行为和性结构所需的每日睾酮脉冲的数量和持续时间尚不清楚。我们也不了解不同季节的环境因素如何影响生殖结构的发育。为了纠正这些缺陷，我们的目标是1)确定支持雄性交配行为的雄激素治疗的最短每日持续时间，以及激素脉冲协同控制阴茎发育的方式；2)建立最初诱导和随后维持性行为的不同雄激素需求；3)评估雄激素对阴茎生长的局部和全身作用的相对贡献；4)指定神经回路，介导类固醇对性行为的脉动影响；以及5)确定睾酮的影响是否由雄激素和/或雌激素受体介导。 在建立正常生殖发育所必需的每日雄激素治疗的最小数量、最低剂量和最佳间隔方面，本工作应为治疗生殖器发育不足的儿童以及成年性腺功能低下的男性带来新的见解和指导方针。这一系列研究应该促进有效的生理干预措施的发展，将与目前治疗人类雄激素分泌障碍的药物治疗相关的不良副作用降至最低。

DESCRIPTION (provided by applicant): This project seeks to specify how ultradian, circadian and seasonal rhythms of androgen availability influence the development and subsequent maintenance of mammalian reproductive structures and behavior. The model species is the Siberian hamster, Phodopus sungorus sungorus. The number and duration of daily testosterone pulses necessary to induce and maintain sexual behavior and structure in male mammals is unknown. Nor do we understand how environmental factors present at different seasons impact on development of reproductive structures. To correct these deficiencies we aim to 1) determine the minimum daily durations of androgen treatments that support mating behavior in males and the manner in which hormone pulses synergize to control penile development, 2) establish the different androgen requirements for initial induction versus subsequent maintenance of sex behavior, 3) assess the relative contributions of local versus systemic actions of androgens on penile growth, 4) specify the neural circuit that mediates pulsatile effects of steroids on sex behavior and 5) determine whether effects of testosterone are mediated by androgen and/or estrogen receptors. In establishing the minimal number, lowest dose, and optimal spacing of daily androgen treatments necessary for normal reproductive development, the present work should lead to new insights and guidelines for treatment of children with insufficient phallic development, as well as treatment of adult hypogonadal men. This line of research should promote development of effective physiological interventions that will minimize undesirable side-effects associated with current pharmacological treatments for human disorders of androgen secretion.