Impact of Auditory Experience on the Structural Plasticity of the AIS in the Mouse Brainstem Throughout the Lifespan
Impact of Auditory Experience on the Structural Plasticity of the AIS in the Mouse Brainstem Throughout the Lifespan
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DOI：
10.3389/fncel.2019.00456
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发表时间：
2019-10-15
影响因子：
5.3
通讯作者：
Kim, Jun Hee
中科院分区：
文献类型：
--
作者：
Kim, Eun Jung;Feng, Chenling;Kim, Jun Hee
声音输入对哺乳动物大脑神经元回路的发育和维持有着至关重要的影响。我们研究了听觉神经元在发育、成年和衰老过程中对各种听觉体验的结构和功能可塑性。采用电生理、计算机模拟和免疫组织化学方法，研究了不同年龄和不同听觉环境下小鼠听性脑干斜方体内侧核（MNTB）轴突起始段（AIS）的结构可塑性。MNTB神经元的AIS的结构和空间位置取决于它们沿着tonotopic轴的功能地形位置，将高频到低频声音响应神经元（HF或LF神经元）对齐。HF神经元在整个生命过程中显著地经历AIS的结构重塑。AIS在发育过程中逐渐缩短，在成年期稳定，并在衰老中变得更长。声音输入与设置和维持AIS可塑性和音调在各个年龄段至关重要。声音刺激增加听觉神经元的兴奋性。计算机模拟显示，AIS长度、位置和直径的改变可以影响发育中脑干中MNTB神经元的放电特性。轴突结构在不同年龄对各种听觉体验的适应能力表明，声音输入对听觉脑的结构和功能特性的发展和维持至关重要。
Sound input critically influences the development and maintenance of neuronal circuits in the mammalian brain throughout life. We investigate the structural and functional plasticity of auditory neurons in response to various auditory experiences during development, adulthood, and aging. Using electrophysiology, computer simulation, and immunohistochemistry, we study the structural plasticity of the axon initial segment (AIS) in the medial nucleus of the trapezoid body (MNTB) from the auditory brainstem of the mice (either sex), in different ages and auditory environments. The structure and spatial location of the AIS of MNTB neurons depend on their functional topographic location along the tonotopic axis, aligning high- to low-frequency sound-responding neurons (HF or LF neurons). HF neurons dramatically undergo structural remodeling of the AIS throughout life. The AIS progressively shortens during development, is stabilized in adulthood, and becomes longer in aging. Sound inputs are critically associated with setting and maintaining AIS plasticity and tonotopy at various ages. Sound stimulation increases the excitability of auditory neurons. Computer simulation shows that modification of the AIS length, location, and diameter can affect firing properties of MNTB neurons in the developing brainstem. The adaptive capability of axonal structure in response to various auditory experiences at different ages suggests that sound input is important for the development and maintenance of the structural and functional properties of the auditory brain throughout life.