Anagnostaras S G, Maren S, DeCola J P, Lane N I, Gale G D, Schlinger B A, Fanselow M S
Department of Psychology, The University of California, Los Angeles 90095-1563, USA.
Behav Brain Res. 1998 Apr;92(1):1-9. doi: 10.1016/s0166-4328(97)00115-0.
We recently reported that Pavlovian fear conditioning and hippocampal perforant-path long-term potentiation (LTP) are sexually dimorphic in rats. Males show greater contextual fear conditioning, which depends on the hippocampus, as well as greater hippocampal LTP. In order to examine the role of circulating gonadal hormones in adult male rats, animals were castrated in two experiments, and Pavlovian fear conditioning and in vivo perforant-path LTP were examined. It was found that sexually-dimorphic LTP and fear conditioning are not regulated by the activational effects of testicular hormones in adult male rats. That is, in every respect, castrated male rats were similar to intact male rats in Pavlovian fear conditioning and hippocampal LTP. It is likely that sexual dimorphism in this system is established earlier in development by the organizational effects of gonadal hormones.
我们最近报道，巴甫洛夫式恐惧条件反射和海马穿通通路长时程增强（LTP）在大鼠中具有性别差异。雄性大鼠表现出更强的情境恐惧条件反射，这依赖于海马体，同时海马LTP也更强。为了研究成年雄性大鼠体内循环性腺激素的作用，在两项实验中对动物进行了阉割，并检测了巴甫洛夫式恐惧条件反射和体内穿通通路LTP。结果发现，成年雄性大鼠的性别差异LTP和恐惧条件反射不受睾丸激素激活作用的调节。也就是说，在各个方面，阉割后的雄性大鼠在巴甫洛夫式恐惧条件反射和海马LTP方面与完整雄性大鼠相似。该系统中的性别差异很可能在发育早期由性腺激素的组织作用所确立。
