Sex Behavior, Phallic Development and Seasonality

描述（由申请人提供）：本项目旨在明确雄激素可用性的昼夜节律和季节节律如何影响哺乳动物生殖结构和行为的发育和后续维持。典型的物种是西伯利亚仓鼠，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丸激素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小每日持续时间，以及激素脉冲协同控制阴茎发育的方式；2)确定初始诱导与随后维持性行为的不同雄激素需求；3)评估雄激素局部作用与全身作用对阴茎生长的相对贡献。4)明确介导类固醇对性行为的脉动效应的神经回路；5)确定睾酮的作用是否由雄激素和/或雌激素受体介导。

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.