Albert D J, Jonik R H, Walsh M L
Psychology Department, University of British Columbia, Vancouver, Canada.
Physiol Behav. 1990 May;47(5):825-30. doi: 10.1016/0031-9384(90)90004-n.
Female hooded rats were ovariectomized and implanted with a single estrogen-filled and a single testosterone-filled Silastic tube. Control animals were ovariectomized and implanted with empty tubes. The implants produced an estrogen concentration of 30 pg/ml and a testosterone concentration of 0.25 ng/ml, levels close to those found in intact females. Two weeks following surgery, all animals were housed in individual cages, placed on a 23-hr food-deprivation schedule, and adapted to a liquid food. They were then housed in hormone-implant/empty-implant pairs and given a series of 3 restricted-access competition tests and 3 free-access competition tests (1/day). The animals were then paired with new partners and given a second series of restricted-access and free-access competition tests. Ovariectomized females with hormone implants were more successful at maintaining access to the liquid food and more aggressive than their competitors without hormone replacement. The aggression was used to maintain access to food during free-access as well as restricted-access competition. Following the competition tests, animals with hormone implants were significantly more aggressive toward an unfamiliar conspecific than were their cagemates with empty implants. The level of success and aggression by females with testosterone + estrogen implants appears greater than that which occurs with either hormone alone and comparable to that observed in intact females.
对雌性带帽大鼠进行卵巢切除，并植入一根填充雌激素的和一根填充睾酮的硅橡胶管。对照动物进行卵巢切除并植入空管。植入物产生的雌激素浓度为30皮克/毫升，睾酮浓度为0.25纳克/毫升，这一水平接近未切除卵巢的雌性大鼠体内的激素水平。手术后两周，所有动物被单独饲养在笼子里，采用23小时食物剥夺方案，并适应液体食物。然后将它们以激素植入/空植入的方式配对，并进行一系列3次限时获取竞争测试和3次自由获取竞争测试（每天1次）。然后将这些动物与新的伙伴配对，并进行第二轮限时获取和自由获取竞争测试。植入激素的卵巢切除雌性大鼠在维持获取液体食物的机会方面比未进行激素替代的竞争对手更成功，也更具攻击性。在自由获取和限时获取竞争中，攻击性被用来维持获取食物的机会。在竞争测试后，植入激素的动物对陌生同种动物的攻击性明显高于植入空管的同笼伙伴。同时植入睾酮和雌激素的雌性大鼠的成功程度和攻击性水平似乎高于单独使用任何一种激素的情况，并且与未切除卵巢的雌性大鼠的情况相当。
