Jones K J
Department of Physical Therapy, University of Illinois, Chicago 60612.
Exp Neurol. 1993 May;121(1):133-8. doi: 10.1006/exnr.1993.1079.
In recent studies, we have shown that administration of androgens to male hamsters enhances functional recovery from facial paralysis induced by facial nerve crush at the level of the stylomastoid foramen. Furthermore, we have established that the mechanism behind this enhancement of regeneration involves an acceleration of the rate of regeneration, without a shortening in the delay of sprout formation. From those studies, several unexpected findings of inherent sex differences emerged. First, intact (nongonadectomized) females have a faster facial nerve regeneration rate than males and, second, testosterone has a less dramatic effect on the rate of regeneration in females compared to males. In the present study, we explored these novel findings of sex differences in the response of motor neurons to injury. Adult intact female hamsters were subjected to right facial nerve crush axotomy at the level of stylomastoid foramen and either implanted with two or four silastic capsules containing 5 alpha-dihydrotestosterone, or sham-implanted for controls. A group of adult intact male hamsters was also subjected to right facial nerve crush axotomy. Animals were observed daily, beginning on Day 1 postoperatively and continuing throughout a 3-week recovery period for signs of functional recovery from facial paralysis. The average day of return of each of four behavioral components (semi-blink, blink reflex, full vibrissae movement, and complete recovery) was calculated for all four experimental groups. The results indicate that intact females recover functional return of movement following crush injury significantly faster than intact males. In contrast to our previous findings in male hamsters, administration of exogenous steroids does not accelerate recovery from facial paralysis in adult female hamsters.(ABSTRACT TRUNCATED AT 250 WORDS)
在最近的研究中，我们发现给雄性仓鼠注射雄激素可增强其因茎乳孔水平面神经挤压所致面瘫后的功能恢复。此外，我们还确定这种再生增强背后的机制涉及再生速率的加快，而芽生形成的延迟并未缩短。从这些研究中，出现了一些关于固有性别差异的意外发现。首先，未阉割的成年雌性仓鼠的面神经再生速率比雄性快，其次，与雄性相比，睾酮对雌性再生速率的影响较小。在本研究中，我们探讨了运动神经元对损伤反应中这些性别差异的新发现。成年未阉割雌性仓鼠在茎乳孔水平接受右侧面神经挤压切断术，然后植入两个或四个含有5α-双氢睾酮的硅橡胶胶囊，或进行假植入作为对照。一组成年未阉割雄性仓鼠也接受右侧面神经挤压切断术。从术后第1天开始每天观察动物，持续整个3周的恢复期，观察面瘫功能恢复的迹象。计算了所有四个实验组四个行为成分（半眨眼、眨眼反射、触须完全运动和完全恢复）各自恢复的平均天数。结果表明，未阉割的雌性仓鼠在挤压损伤后运动功能恢复明显快于未阉割的雄性仓鼠。与我们之前在雄性仓鼠中的发现相反，给予外源性类固醇并不会加速成年雌性仓鼠面瘫后的恢复。（摘要截短至250字）
