Effects of early auditory experiences on song discrimination in female zebra finches, Taeniopygia guttata

雄性斑胸草雀在发育过程中通过记忆和模仿父亲的歌声来学习唱歌，以吸引雌性。另一方面，女性对熟悉的歌曲（通常是父亲的歌曲）表现出空间接近或强化行为，这表明她们在发育过程中也通过听到成年男性的歌曲在大脑中形成歌曲记忆。在次级听觉皮层，尾内侧巢皮层（NCM）和尾内侧中皮层（CMM）的神经元显示熟悉的歌曲听觉反应，然而，在女性的歌曲记忆形成和/或歌曲识别的神经基础仍然不清楚。在这里，我们探讨了雌性斑胸草雀的NCM和/或CMM是否涉及作为歌曲偏好行为基础的父亲歌曲记忆的神经元底物。我们采用了两个操作性的选择偏好测试，鲈鱼跳测定，发现女性表现出显着较弱的偏好，他们的父亲的歌曲后，双边化学病变的CMM。双侧假病变（PBS注射）的雌性动物没有改变其偏好。此外，我们通过使用腺相关病毒载体（AAV-cFOS-Tet-ON-Caspase 3和AAV-cFOS-Tet-ON-DTA）诱导NCM或CMM神经元的凋亡，所述神经元对它们父亲的歌曲的播放作出反应。这些雌性在神经元细胞死亡的诱导下也表现出对父亲歌曲的偏好下降。总之，NCM和CMM中的父歌反应神经元是父歌偏好行为所必需的。

Zebra finch males learn to sing by memorizing and mimicking their father’s songs during development for attracting females. On the other hand, females show spatial approaches or reinforced behaviors to familiar (normally their father’s) songs, suggesting they also form song memories in their brain by hearing adult male songs during development. Neurons in the secondary auditory cortex, caudomedial nidopallium (NCM) and caudomedial mesopallium (CMM) show auditory responsiveness to familiar songs, however, the neural bases for song memory formation and/or song recognition in females has remained unclear. Here we explored if the NCM and/or CMM in female zebra finches involves the neuronal substrates for father song memory as a basis for song preference behavior. We employed a two-operant choices preference test, perch-hop assay, and found that females showed a significantly weaker preference to their fathers’ songs after bilateral chemical lesions of the CMM. Females with bilateral sham lesions (PBS injection) did not change their preference. Furthermore, we induced apoptosis in the NCM or CMM neurons which responded to the playback of their father’s songs by using adeno-associated viral vectors (AAV-cFOS-Tet-ON-Caspase3 and AAV-cFOS-Tet-ON-DTA). These females also showed a decreased preference to their fathers’ songs after the inductions of neuronal cell death. Taken together, father song responsive neurons both in the NCM and CMM are necessary for father song preference behavior.