Gobes Sharon M H, Ter Haar Sita M, Vignal Clémentine, Vergne Amélie L, Mathevon Nicolas, Bolhuis Johan J
Behavioural Biology and Helmholtz Institute, Utrecht University, 3508 TB Utrecht, the Netherlands.
J Comp Neurol. 2009 Oct 1;516(4):312-20. doi: 10.1002/cne.22113.
In zebra finches (Taeniopygia guttata), as in most other songbird species, there are robust sex differences in brain morphology and vocal behavior. First, male zebra finches have larger song system nuclei--involved in sensorimotor learning and production of song--than females. Second, male zebra finches learn their song from a tutor, whereas female zebra finches develop a learned preference for the song of their father but do not sing themselves. Third, female zebra finches produce an unlearned "long call," while males learn their long call (which is different from that of females) from their song tutor. We investigated behavioral and molecular neuronal responsiveness to this sexually dimorphic communication signal. Behavioral responsiveness was quantified by measuring the number of calls and approaches in response to calls that were broadcast from a speaker. We quantified neuronal activation by measuring the number of neurons expressing Zenk, the protein product of the immediate early gene ZENK, in a number of different forebrain regions in response to male calls, to female calls, or to silence. In both sexes female calls evoked more calls and approaches than male calls. There was significantly greater Zenk expression in response to female calls compared to silence in the caudomedial nidopallium, caudomedial mesopallium, and the hippocampus in females, but not in males. Thus, male and female zebra finches both show a behavioral preference for female calls, but differential neuronal activation in response to sexually dimorphic calls.
与大多数其他鸣禽物种一样，斑胸草雀（Taeniopygia guttata）在大脑形态和发声行为上存在明显的性别差异。首先，雄性斑胸草雀参与感觉运动学习和发声的鸣唱系统核团比雌性更大。其次，雄性斑胸草雀从导师那里学习它们的歌声，而雌性斑胸草雀则对其父亲的歌声形成一种习得的偏好，但自己并不唱歌。第三，雌性斑胸草雀会发出一种非习得的“长鸣”，而雄性则从它们的鸣唱导师那里学习它们的长鸣（与雌性的不同）。我们研究了对这种性别二态性通讯信号的行为和分子神经元反应。行为反应通过测量对扬声器播放的叫声做出反应的叫声数量和接近次数来量化。我们通过测量在一些不同前脑区域中表达Zenk（即刻早期基因ZENK的蛋白质产物）的神经元数量，来量化对雄性叫声、雌性叫声或静音做出反应时的神经元激活情况。在两性中，雌性叫声比雄性叫声引发了更多的叫声和接近行为。与静音相比，雌性的尾内侧巢皮质、尾内侧中脑皮质和海马体中，对雌性叫声有明显更强的Zenk表达，而雄性则没有。因此，雄性和雌性斑胸草雀都对雌性叫声表现出行为偏好，但对性别二态性叫声的神经元激活存在差异。
