Brenowitz E A, Arnold A P
Department of Psychology, University of Washington, Seattle 98195.
Brain Res. 1989 Feb 20;480(1-2):119-25. doi: 10.1016/0006-8993(89)91574-6.
Tritiated estradiol (E) was injected into bay wrens (Thryothorus nigricapillus), a tropical species in which females sing complex vocal duets with males. Autoradiographic analysis revealed that males and females have equal proportions of cells labeled by estradiol or its metabolites (E target cells) in a telencephalic region involved in song: the caudal nucleus of the ventral hyperstriatum (HVc). Other forebrain song regions failed to show labeling by E. E or its metabolites were accumulated, however, by cells in the midbrain song region ICo (the intercollicular nucleus) and in hypothalamic regions. This pattern of accumulation in the song system differs from that observed in a previous study in which bay wrens were injected with tritiated testosterone (T); T or its metabolites were accumulated by cells in HVc, RA (robust nucleus of the archistriatum), MAN (magnocellular nucleus of the neostriatum), ICo, and nXII (hypoglossal (nucleus). Such comparison suggests that cells in HVc have different steroid accumulation properties from those in other song regions. Bay wrens differ from zebra finches (Poephilia guttata), in which HVc contains very few E target cells. The wrens are more similar to canaries (Serinus canarius), because both species have E target cells in HVc, and females of both species are able to sing. The interspecies comparison raises the question of whether the ability of HVc cells to accumulate E or its metabolites in both species constitutes a precondition for the bisexual potential for song production.
将氚标记的雌二醇（E）注射到海湾鹪鹩（黑顶弯嘴鹪鹩，Thryothorus nigricapillus）体内，这是一种热带鸟类，其雌性会与雄性进行复杂的声乐二重唱。放射自显影分析显示，在参与鸣叫的端脑区域——腹侧超纹状体尾核（HVc）中，雄性和雌性被雌二醇或其代谢产物标记的细胞（E靶细胞）比例相等。其他前脑鸣叫区域未显示出被E标记。然而，E或其代谢产物在中脑鸣叫区域ICo（间丘核）和下丘脑区域的细胞中积累。鸣叫系统中的这种积累模式与之前一项研究中给海湾鹪鹩注射氚标记的睾酮（T）时观察到的模式不同；T或其代谢产物在HVc、RA（古纹状体粗核）、MAN（新纹状体大细胞核）、ICo和nXII（舌下神经核）的细胞中积累。这种比较表明，HVc中的细胞与其他鸣叫区域的细胞具有不同的类固醇积累特性。海湾鹪鹩与斑胸草雀（Poephilia guttata）不同，斑胸草雀的HVc中几乎没有E靶细胞。鹪鹩与金丝雀（Serinus canarius）更相似，因为这两个物种的HVc中都有E靶细胞，且两个物种的雌性都能鸣叫。种间比较提出了一个问题，即这两个物种中HVc细胞积累E或其代谢产物的能力是否构成了两性鸣叫产生潜力的先决条件。
