Wade J, Huang J M, Crews D
Department of Psychology, University of Texas, Austin.
J Neuroendocrinol. 1993 Feb;5(1):81-93. doi: 10.1111/j.1365-2826.1993.tb00366.x.
The effects of steroid hormones on sexual dimorphisms in the brain, behavior and accessory sex structures were investigated in two species of whiptail lizards. The studies were conducted both in adults and hatchlings of a sexually reproducing species (Cnemidophorus inornatus) and an all-female species (C. uniparens) which displays 'sexual' behaviors typical of males and females. Adults were gonadectomized and approximately 3 months later given either a Silastic capsule filled with sex steroid or an empty capsule. Young animals of both species were left intact and given a capsule on the day of hatching. An additional group of C. uniparens was ovariectomized on the day of hatching. Following treatment, measures of oviduct (estrogen-dependent), renal sex segment (androgen-dependent) and wolffian duct (androgen-dependent) hypertrophy were taken in some experiments. Animals were also tested for sexual behavior in some of the studies. The volumes of the anterior hypothalamus-preoptic area and ventromedial hypothalamus were measured in each individual. Estrogen, testosterone and dihydrotestosterone stimulated peripheral structures at both time periods in both sexes and species. The hormones also stimulated courtship and copulatory behaviors in many of the adult animals. However, testosterone in the anterior hypothalamus-preoptic area of male C. inornatus was the only treatment which produced parallel effects on the volume of a brain area and the behaviors which it controls. These data add whiptail lizards to the list of species in which steroid hormones affect the volume of brain regions in adulthood, but suggest that such changes in morphology are not necessarily predictive of functional differences.
在两种鞭尾蜥中研究了类固醇激素对大脑、行为和附属生殖结构性别二态性的影响。研究在有性繁殖物种（饰纹鞭尾蜥）和全雌性物种（单性鞭尾蜥）的成年个体和幼体中进行，单性鞭尾蜥表现出典型的雄性和雌性“性行为”。对成年个体进行性腺切除，大约3个月后，给它们植入一个装有性类固醇的硅橡胶胶囊或一个空胶囊。两种物种的幼体不做处理，在孵化当天给它们植入一个胶囊。另一组单性鞭尾蜥在孵化当天进行卵巢切除。处理后，在一些实验中测量了输卵管（雌激素依赖）、肾性节（雄激素依赖）和中肾管（雄激素依赖）的肥大情况。在一些研究中还对动物的性行为进行了测试。测量了每个个体下丘脑前视前区和腹内侧下丘脑的体积。雌激素、睾酮和双氢睾酮在两个时间段对两性和两个物种的外周结构均有刺激作用。这些激素还刺激了许多成年动物的求偶和交配行为。然而，雄性饰纹鞭尾蜥下丘脑前视前区的睾酮是唯一一种对脑区体积及其控制的行为产生平行影响的处理方式。这些数据将鞭尾蜥添加到类固醇激素在成年期影响脑区体积的物种列表中，但表明这种形态学变化不一定能预测功能差异。
