Forger N G, Wong V, Breedlove S M
Department of Psychology, University of Massachusetts, Amherts, USA.
J Neurobiol. 1995 Nov;28(3):354-62. doi: 10.1002/neu.480280308.
Steroid hormones and neurotrophic factors exert profound and widespread effects on the developing nervous system, including regulation of the size, connectivity, and survival of neurons. Androgenic control of the survival of motoneurons in the spinal nucleus of the bulbocavernosus (SNB) of rats has been well documented. We previously found that ciliary neurotrophic factor (CNTF) mimics many effects of androgen on the developing SNB. Whether effects of CNTF depend on the presence of a functional androgen receptor was evaluated in the present study. Androgen-insensitive male rats bearing the testicular feminization mutation, Tfm, and female litter-mates were treated with CNTF or with vehicle alone from embryonic day 22 through postnatal day 3. On postnatal day 4 SNB cell number was elevated in both groups receiving CNTF. Volumes of the bulbocavernosus (BC) and levator ani (LA) muscles, targets of SNB motoneurons, were also markedly increased by CNTF. Since the BC appears to degenerate completely in untreated females, these results indicate that CNTF can delay or prevent muscle fiber death. The relative sparing of muscles and motoneurons did not differ for Tfm males and females, demonstrating that effects of CNTF on the SNB neuromuscular system do not require functional androgen receptors.
类固醇激素和神经营养因子对发育中的神经系统具有深远而广泛的影响，包括对神经元大小、连接性和存活的调节。雄激素对大鼠球海绵体肌核（SNB）中运动神经元存活的控制已有充分记载。我们先前发现，睫状神经营养因子（CNTF）模拟了雄激素对发育中的SNB的许多作用。本研究评估了CNTF的作用是否依赖于功能性雄激素受体的存在。携带睾丸雌性化突变Tfm的雄激素不敏感雄性大鼠和雌性同窝仔鼠从胚胎第22天到出生后第3天接受CNTF或仅接受载体处理。在出生后第4天，接受CNTF的两组SNB细胞数量均增加。CNTF还显著增加了SNB运动神经元的靶标球海绵体肌（BC）和肛提肌（LA）的体积。由于在未处理的雌性中BC似乎完全退化，这些结果表明CNTF可以延迟或防止肌纤维死亡。Tfm雄性和雌性的肌肉和运动神经元相对保留情况没有差异，表明CNTF对SNB神经肌肉系统的作用不需要功能性雄激素受体。
