Schlinger B A, Arnold A P
Department of Psychology, University of California, Los Angeles 90024-1563.
Proc Natl Acad Sci U S A. 1991 May 15;88(10):4191-4. doi: 10.1073/pnas.88.10.4191.
The neural system controlling song in passerine birds can undergo striking morphological and functional changes during both development and adulthood, and many of these changes are regulated by estrogenic hormones. Estrogens circulate at high levels in blood of male songbirds and persist after castration. We measured the activity of aromatase, the enzyme that converts androgens to estrogens, in various tissues from adult male and female zebra finches. As expected, aromatase activity was present in male hypothalamus/preoptic area and pituitary and female ovary, but aromatase was unusually active in whole telencephalon of males and females. By contrast, activity was undetected in testes, adrenals, or other tissues of males. These results suggest that brain is the source of circulating estrogens in the male zebra finch and that estrogen actions on the song system result from local rather than peripheral aromatization.
在鸣禽中，控制鸣叫的神经系统在发育和成年期都会发生显著的形态和功能变化，其中许多变化受雌激素调节。雌激素在雄性鸣禽血液中循环水平较高，阉割后仍持续存在。我们测量了成年雄性和雌性斑胸草雀不同组织中芳香化酶（将雄激素转化为雌激素的酶）的活性。正如预期的那样，芳香化酶活性存在于雄性下丘脑/视前区、垂体以及雌性卵巢中，但在雄性和雌性的整个端脑中，芳香化酶异常活跃。相比之下，在雄性的睾丸、肾上腺或其他组织中未检测到活性。这些结果表明，大脑是雄性斑胸草雀循环雌激素的来源，并且雌激素对鸣叫系统的作用源于局部而非外周的芳香化作用。
