Differential development of myelin in zebra finch song nuclei
Differential development of myelin in zebra finch song nuclei
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DOI：
10.1002/cne.25019
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发表时间：
2020-09-16
影响因子：
2.5
通讯作者：
Perkel, David J.
中科院分区：
文献类型：
--
作者：
Champoux, Katharine L.;Miller, Kimberly E.;Perkel, David J.
鸣鸟通过听和练习歌曲来学习发声。随着歌曲的发展，克里思变得更快，更精确。在鸣禽的大脑中，离散的核团形成了相互连接的有髓鞘回路，控制着歌曲的获得和产生。髓鞘通过隔离神经元的轴突和减少膜电容来增加动作电位传播的速度。随着大脑的发育，髓鞘的密度增加，但髓鞘在离散的鸣唱核中发育的时间过程还没有被系统地定量研究。我们测试的假设，髓鞘的发展差异，在不同的时间和歌曲核。我们研究了斑胸草雀（Taeniopygia guttata）从孵化后第8天（d）到成年（最长147 d）的5个主要鸣唱核团的髓鞘发育：HVC（专有名称）、弓皮质强健核（RA）、X区、前巢皮质外侧大细胞核和丘脑背外侧核内侧部（DLM）。所有这些细胞核在发育过程中都表现出髓鞘形成密度的增加，但速度不同，最终程度也不同。指数曲线拟合显示，DLM表现出较早的髓鞘形成比其他核，和HVC表现出最慢的髓鞘形成的歌曲核。总之，这些数据显示了不同的成熟髓鞘在不同部分的歌曲系统。这种差异性成熟将很好地在调节习得歌曲的发展方面发挥作用。
Songbirds learn vocalizations by hearing and practicing songs. As song develops, the tempo becomes faster and more precise. In the songbird brain, discrete nuclei form interconnected myelinated circuits that control song acquisition and production. The myelin sheath increases the speed of action potential propagation by insulating the axons of neurons and by reducing membrane capacitance. As the brain develops, myelin increases in density, but the time course of myelin development across discrete song nuclei has not been systematically studied in a quantitative fashion. We tested the hypothesis that myelination develops differentially across time and song nuclei. We examined myelin development in the brains of the zebra finch (Taeniopygia guttata) from chick at posthatch day (d) 8 to adult (up to 147 d) in five major song nuclei: HVC (proper name), robust nucleus of the arcopallium (RA), Area X, lateral magnocellular nucleus of the anterior nidopallium, and medial portion of the dorsolateral thalamic nucleus (DLM). All of these nuclei showed an increase in the density of myelination during development but at different rates and to different final degrees. Exponential curve fits revealed that DLM showed earlier myelination than other nuclei, and HVC showed the slowest myelination of song nuclei. Together, these data show differential maturation of myelination in different portions of the song system. Such differential maturation would be well placed to play a role in regulating the development of learned song.