Perlman William R, Ramachandran Baskaran, Arnold Arthur P
Department of Physiological Science, Interdepartmental Program for Neuroscience and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California 90095-1606, USA.
J Comp Neurol. 2003 Jan 20;455(4):513-30. doi: 10.1002/cne.10510.
Zebra finch males sing and females do not, and the underlying neural circuitry in males is more developed than that in females. Sex steroid hormones influence the development of sex differences in this circuitry, including differences in androgen receptor (AR) expression, although the role of androgens has been controversial. We isolated a cDNA encoding a portion of the zebra finch AR and used in situ hybridization to examine the spatiotemporal pattern of AR mRNA expression in the brain during late embryonic development and at hatching. We detected AR mRNA in all the major subdivisions of the brain as early as embryonic day 10. No qualitative sex differences in AR mRNA expression patterns were observed. Cells lining the ventral arm of the lateral telencephalic ventricles expressed AR mRNA on embryonic day 11 and posthatching day 1, as did cells lining the third ventricle at all three developmental stages examined, suggesting that androgens may play a role in early stages of cellular proliferation, migration, or differentiation. AR mRNA was also detected in the hippocampus, neostriatum, septum, ventromedial archistriatum, hypothalamic regions, dorsal mesencephalon, and in and around the brainstem nucleus tracheosyringealis. Our results suggested that androgens act early in neural development and therefore may contribute to the process of sexual differentiation.
雄性斑胸草雀会唱歌而雌性不会，并且雄性体内的基础神经回路比雌性的更发达。性类固醇激素会影响该神经回路中性别差异的发育，包括雄激素受体（AR）表达的差异，尽管雄激素的作用一直存在争议。我们分离出了一段编码斑胸草雀AR部分序列的cDNA，并使用原位杂交技术来检测胚胎发育后期和孵化时大脑中AR mRNA表达的时空模式。早在胚胎第10天，我们就在大脑的所有主要亚区检测到了AR mRNA。未观察到AR mRNA表达模式存在定性的性别差异。在胚胎第11天和孵化后第1天，侧脑室腹侧臂内衬的细胞表达AR mRNA，在所检测的所有三个发育阶段，第三脑室内衬的细胞也表达AR mRNA，这表明雄激素可能在细胞增殖、迁移或分化的早期阶段发挥作用。在海马体、新纹状体、隔区、腹内侧原纹状体、下丘脑区域、中脑背侧以及气管旁核及其周围也检测到了AR mRNA。我们的结果表明，雄激素在神经发育早期起作用，因此可能有助于性别分化过程。
