Ovariectomy attenuates dendritic growth in hormone-sensitive spinal motoneurons.
Ovariectomy attenuates dendritic growth in hormone-sensitive spinal motoneurons.
复制标题
卵巢切除术减弱了激素敏感的脊髓运动神经元的树突生长。
DOI：
10.1002/neu.1059
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Sengelaub,DR
中科院分区：
文献类型：
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作者：
Hebbeler,SL;Verhovshek,T;Sengelaub,DR
大鼠的腰髓含有性二态性、类固醇敏感的球海绵体肌脊髓核（SNB）。雄性大鼠SNB运动神经元的树突发育是双相的，最初在4周龄时表现出旺盛的生长，随后在7周龄时收缩至成熟长度。最初的生长是类固醇依赖性的，通过去势或芳香酶抑制而减弱，并通过激素替代来支持。树突回缩也是类固醇敏感的，可以通过睾酮治疗来预防，但不受芳香酶抑制的影响。总之，这些结果表明雌激素在SNB发育的初始生长阶段发挥了作用。在这项研究中，我们测试了卵巢激素是否可以支持SNB体细胞和树突状细胞的发育。运动神经元形态进行了评估，在正常男性和女性围产期雄性化与双氢睾酮，然后要么卵巢切除或保持完整。SNB运动神经元在4或7周龄时用霍乱毒素-HRP逆行标记，并进行三维重建。SNB树突的初始生长减少卵巢切除术后，男性化的女性。然而，在7周龄时，完整和卵巢切除的男性化女性之间的树突长度没有差异，两组的长度均显着低于正常男性。与以前的研究结果一起，这些结果表明雌激素参与SNB树突的早期生长，但不参与随后的收缩。John Wiley & Sons，Inc. J Neurobiol 48：301-314，2001
The lumbar spinal cord of rats contains the sexually dimorphic, steroid‐sensitive spinal nucleus of the bulbocavernosus (SNB). Dendritic development of SNB motoneurons in male rats is biphasic, initially showing exuberant growth through 4 weeks of age followed by a retraction to mature lengths by 7 weeks of age. The initial growth is steroid dependent, attenuated by castration or aromatase inhibition, and supported by hormone replacement. Dendritic retraction is also steroid sensitive and can be prevented by testosterone treatment, but is unaffected by aromatase inhibition. Together, these results suggest a role for estrogens during the initial growth phase of SNB development. In this study, we tested whether ovarian hormones could support SNB somal and dendritic development. Motoneuron morphology was assessed in normal males and in females perinatally masculinized with dihydrotestosterone and then either ovariectomized or left intact. SNB motoneurons were retrogradely labeled with cholera toxin‐HRP at 4 or 7 weeks of age and reconstructed in three dimensions. Initial growth of SNB dendrites was reduced after ovariectomy in masculinized females. However, no differences in dendritic length were seen at 7 weeks of age between intact and ovariectomized masculinized females, and lengths in both groups were significantly lower than those of normal males. Together with previous findings, these results suggest that estrogens are involved in the early growth of SNB dendrites, but not in their subsequent retraction. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 301–314, 2001