caa a22 4500 469083204 CHVBK 20180323132956.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF00645057 doi (NATIONALLICENCE)springer-10.1007/BF00645057 Sex steroids do not alter sex differences in tyrosine hydroxylase activity of dopaminergic neurons in vitro [Elektronische Daten] [Cordian Beyer, Beate Eusterschulte, Christof Pilgrim, Ingrid Reisert] Summary: In order to distinguish the effects of genetic sex from those of sex hormones on the sexual differentiation of dopaminergic neurons, catecholamine synthesis was studied in gender-specific cultures of embryonic day-14 rat diencephalon. In addition to embryos from normal dams, embryos were used whose mothers had been treated with the estrogen antagonist tamoxifen or the testosterone antagonist cyproterone acetate on days 12 and 13 of gestation. Cultures from embryos of untreated dams were fed daily with a medium containing 17β-estradiol or testosterone. After 10 days in vitro, cultures were immunostained for tyrosine hydroxylase and the accumulation of dihydroxyphenylalanine (DOPA) was measured in the presence of the DOPA decarboxylase inhibitor NSD 1015. Rates of DOPA synthesis, unlike the numbers of tyrosine hydroxylase-immunoreactive neurons, were markedly higher in female cultures under all experimental conditions. Treatment of dams with antisteroids prior to removal of the embryos had no influence on these results. Treatment of cultures with both steroids decreased DOPA formation in a dose-dependent manner without altering the sex difference. These results suggest that cultured diencephalic dopaminergic neurons develop sex differences in the activity of tyrosine hydroxylase. This sexual dimorphism is initiated independently of the action of gonadal steroid hormones. Sex hormones exert an additional modulatory influence on the activity of the enzyme but do not abolish or reverse sex differences. Therefore, the concept of a purely epigenetic mode of sexual differentiation of the mammalian brain needs to be broadened to incorporate other mechanisms, such as the cell-autonomous fulfillment of a sex-specific genetic program. Springer-Verlag, 1992 Sex differences nationallicence Development nationallicence Cell culture, CNS nationallicence Catecholamine synthesis nationallicence Antisteroids nationallicence Rat (Sprague Dawley, Wiga) nationallicence Beyer Cordian Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut Eusterschulte Beate Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut Pilgrim Christof Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut Reisert Ingrid Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut Cell and Tissue Research Springer-Verlag 270/3(1992-12-01), 547-552 0302-766X 270:3<547 1992 270 441 https://doi.org/10.1007/BF00645057 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00645057 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Beyer Cordian Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut NATIONALLICENCE 700 1- Eusterschulte Beate Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut NATIONALLICENCE 700 1- Pilgrim Christof Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut NATIONALLICENCE 700 1- Reisert Ingrid Abteilung Anatomie und Zellbiologie der Universität, Albert-Einstein-Allee 11, W-7900, Ulm, Federal Republic of Germany aut NATIONALLICENCE 773 0- Cell and Tissue Research Springer-Verlag 270/3(1992-12-01), 547-552 0302-766X 270:3<547 1992 270 441 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer