Prange-Kiel Janine, Schmutterer Tobias, Fester Lars, Zhou Lepu, Imholz Philipp, Brandt Nicola, Vierk Ricardo, Jarry Hubertus, Rune Gabriele M
University of Texas Southwestern Medical Center at Dallas, Department of Cell Biology, 5323 Harry Hines Blvd., Dallas, Texas 75390, USA.
Prog Histochem Cytochem. 2013 Aug;48(2):49-64. doi: 10.1016/j.proghi.2013.07.002. Epub 2013 Jul 29.
Estradiol synthesis in the ovaries is regulated via feedback mechanisms mediated by gonadotrophin-releasing hormone (GnRH) and gonadotrophins, secreted by the hypothalamus and the pituitary, respectively. Estradiol synthesis also takes place in the hippocampus. In hippocampal slice cultures of female animals, GnRH regulates estradiol synthesis dose-dependently. Hence, both hippocampal and ovarian estradiol synthesis are synchronized by GnRH. Hippocampus-derived estradiol is essential to synapse stability and maintenance because it stabilizes the spine cytoskeleton of hippocampal neurons. Inhibition of hippocampal estradiol synthesis in mice, however, results in loss of spines and spine synapses in females, but not in males. Stereotaxic application of GnRH to the hippocampus of female rats confirms the regulatory role of GnRH on estradiol synthesis and synapse density in the female hippocampus in vivo. This regulatory role of GnRH necessarily results in estrus cyclicity of spine density in the hippocampus of females.
卵巢中的雌二醇合成通过由下丘脑和垂体分别分泌的促性腺激素释放激素（GnRH）和促性腺激素介导的反馈机制进行调节。雌二醇合成也发生在海马体中。在雌性动物的海马体切片培养物中，GnRH以剂量依赖的方式调节雌二醇合成。因此，海马体和卵巢中的雌二醇合成均由GnRH同步。海马体衍生的雌二醇对于突触稳定性和维持至关重要，因为它能稳定海马体神经元的棘突细胞骨架。然而，抑制小鼠海马体中的雌二醇合成会导致雌性而非雄性的棘突和棘突突触丧失。将GnRH立体定向应用于雌性大鼠的海马体，证实了GnRH在体内对雌性海马体中雌二醇合成和突触密度的调节作用。GnRH的这种调节作用必然导致雌性海马体中棘突密度的发情周期变化。
