Experience-Dependent Coding of Time-Dependent Frequency Trajectories by Off Responses in Secondary Auditory Cortex
Experience-Dependent Coding of Time-Dependent Frequency Trajectories by Off Responses in Secondary Auditory Cortex
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DOI：
10.1523/jneurosci.2665-19.2020
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发表时间：
2020-06-03
影响因子：
5.3
通讯作者：
Liu, Robert C.
中科院分区：
文献类型：
--
作者：
Chong, Kelly K.;Anandakumar, Dakshitha B.;Liu, Robert C.
与时间相关的频率轨迹是许多行为相关声音的固有特征，例如物种特异性发声。动态频率轨迹，即使是短声音，也常常传达有意义的信息，这些信息可用于区分声音类别。然而，目前尚不清楚听觉皮层通路中的神经反应是什么以及在哪里对于传达行为相关频率轨迹的信息至关重要，以及这些反应如何随着经验而变化。在这里，我们发现调谐到微妙的变化，频率轨迹在听觉皮层的雌性小鼠。我们发现，听觉皮层反应可以通过纯音轨迹的变化来调制，这些变化小到八度的1/24，与灵长类动物的报告相当。特别是，后期尖峰结束后的声音刺激更经常敏感的声音的微妙的频率变化相比，尖峰在声音。这种“关”的反应，在成人A2，但不是那些在核心听觉皮层，是塑料的方式，可能会提高代表性的一个新获得的，行为相关的声音类别。我们说明了这与自然发声学习的母鼠范例。通过使用行为学启发的范例来驱动高阶神经元的听觉反应，我们的研究结果表明，小鼠听觉皮层可以跟踪精细的频率变化，这使得A2 Off响应特别能够更好地响应区分行为相关的自然声音类别的音高轨迹。
Time-dependent frequency trajectories are an inherent feature of many behaviorally relevant sounds, such as species-specific vocalizations. Dynamic frequency trajectories, even in short sounds, often convey meaningful information, which may be used to differentiate sound categories. However, it is not clear what and where neural responses in the auditory cortical pathway are critical for conveying information about behaviorally relevant frequency trajectories, and how these responses change with experience. Here, we uncover tuning to subtle variations in frequency trajectories in auditory cortex of female mice. We found that auditory cortical responses could be modulated by variations in a pure tone trajectory as small as 1/24th of an octave, comparable to what has been reported in primates. In particular, late spiking after the end of a sound stimulus was more often sensitive to the sound's subtle frequency variation compared with spiking during the sound. Such "Off" responses in the adult A2, but not those in core auditory cortex, were plastic in a way that may enhance the representation of a newly acquired, behaviorally relevant sound category. We illustrate this with the maternal mouse paradigm for natural vocalization learning. By using an ethologically inspired paradigm to drive auditory responses in higher-order neurons, our results demonstrate that mouse auditory cortex can track fine frequency changes, which allows A2 Off responses in particular to better respond to pitch trajectories that distinguish behaviorally relevant, natural sound categories.