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

雄性斑马雀在发育过程中通过记忆和模仿父亲的歌曲来学习唱歌，以吸引雌性斑马雀。另一方面，女性对熟悉的(通常是她们父亲的)歌曲表现出空间上的接近或强化的行为，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了歌曲记忆。次级听觉皮质、尾内侧nidopallium(NCM)和尾内侧系膜(Cmm)的神经元对熟悉的歌曲表现出听觉反应，然而，女性歌曲记忆形成和/或歌曲识别的神经基础尚不清楚。在这里，我们探索了雌性斑马雀的NCM和/或CMM是否涉及父亲歌曲记忆的神经元底物，作为歌曲偏好行为的基础。我们采用了一种双操作选择偏好测试，即Perch-hop分析，发现在CMM的双侧化学损伤后，女性对父亲的歌曲表现出明显较弱的偏好。有双侧假病变的女性(注射PBS)不会改变她们的偏好。此外，我们用腺相关病毒载体(AAV-CFOS-Tet-on-Caspase3和AAV-CFOS-Tet-on-DTA)诱导了NCM或CMM神经元的凋亡，这些神经元对父亲的歌曲回放有反应。在诱导神经细胞死亡后，这些雌性动物对父亲的歌曲也表现出更低的偏好。综上所述，NCM和CMM中的父亲歌曲反应神经元对于父亲歌曲偏好行为都是必需的。

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.