Arnold A P
Department of Psychology, University of California, Los Angeles 90024-1563.
J Neurobiol. 1992 Dec;23(10):1506-28. doi: 10.1002/neu.480231010.
In many species of passerine songbirds, males learn their song during defined periods of life. Female song is often reduced or absent, as are the brain regions controlling song. Sexual differences in the brain arise because of the action of sex steroids, which trigger the formation of some neural pathways (especially the pathway from the higher vocal center to the robust nucleus) and prevent the atrophy of others in males. These neural changes occur during periods of developmental song learning and can recur during periods of learning in adult birds. The process of learning is correlated with major increases or decreases in the numbers of neurons in specific neuronal populations, suggesting that the formation or loss of specific neural pathways regulates the ability to learn. Species differences in sexual differentiation and learning allow informative cross-species comparisons of neural structure and behavior.
在许多雀形目鸣禽物种中，雄性在特定的生命阶段学习它们的歌声。雌性的歌声通常减少或没有，控制歌声的脑区也是如此。大脑中的性别差异是由性类固醇的作用引起的，性类固醇触发了一些神经通路（特别是从高级发声中枢到粗壮核的通路）的形成，并防止雄性其他神经通路萎缩。这些神经变化发生在发育性歌声学习阶段，并且在成年鸟类学习阶段可能再次出现。学习过程与特定神经元群体中神经元数量的大幅增加或减少相关，这表明特定神经通路的形成或丧失调节了学习能力。性别分化和学习方面的物种差异使得对神经结构和行为进行有益的跨物种比较成为可能。
