Maturation of Spontaneous Firing Properties after Hearing Onset in Rat Auditory Nerve Fibers: Spontaneous Rates, Refractoriness, and Interfiber Correlations
Maturation of Spontaneous Firing Properties after Hearing Onset in Rat Auditory Nerve Fibers: Spontaneous Rates, Refractoriness, and Interfiber Correlations
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DOI：
10.1523/jneurosci.1187-16.2016
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发表时间：
2016-10-12
影响因子：
5.3
通讯作者：
Glowatzki, Elisabeth
中科院分区：
文献类型：
--
作者：
Wu, Jingjing Sherry;Young, Eric D.;Glowatzki, Elisabeth
听觉神经纤维（ANFs）表现出一系列与声音阈值负相关的自发放电率（SRs）。为了探讨耳蜗成熟过程中srf分化的潜在机制和时间进程，我们在听力发作后使用不同年龄的急性切除大鼠耳蜗，对ANF树突进行了松散斑块的细胞外记录。SRs的多样化主要发生在产后第二周和第三周之间。ANF尖峰序列的统计特性显示了在较老的制剂中接近成人特征的发育变化。与细胞内记录的EPSCs比较发现，ANF尖峰序列的大部分特性源于突触前递质释放的特性。药理学试验和波形分析表明，内源性放电产生部分ANF尖峰，说明其不寻常的性质；内源性放电在成熟过程中逐渐减弱。配对记录显示，接触同一内毛细胞的anf可能有不同的SRs，但它们的峰值时间没有相关性。
Auditory nerve fibers (ANFs) exhibit a range of spontaneous firing rates (SRs) that are inversely correlated with threshold for sounds. To probe the underlying mechanisms and time course ofSRdifferentiation during cochlear maturation, loose-patch extracellular recordings were made from ANF dendrites using acutely excised rat cochlear preparations of different ages after hearing onset. Diversification of SRs occurred mostly between the second and the third postnatal week. Statistical properties of ANF spike trains showed developmental changes that approach adult-like features in older preparations. Comparison with intracellularly recorded EPSCs revealed that most properties of ANF spike trains derive from the characteristics of presynaptic transmitter release. Pharmacological tests and waveform analysis showed that endogenous firing produces some fraction of ANF spikes, accounting for their unusual properties; the endogenous firing diminishes gradually during maturation. Paired recordings showed that ANFs contacting the same inner hair cell could have different SRs, with no correlation in their spike timing.