Hintze Anika, Gültas Mehmet, Semmelhack Esther A, Wichmann Carolin
Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience, InnerEarLab and Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany.
Collaborative Research Center 1286, University of Göttingen, Göttingen, Germany.
iScience. 2021 Mar 8;24(4):102282. doi: 10.1016/j.isci.2021.102282. eCollection 2021 Apr 23.
Endbulbs of Held are located in the anteroventral cochlear nucleus and present the first central synapses of the auditory pathway. During development, endbulbs mature functionally to enable rapid and powerful synaptic transmission with high temporal precision. This process is accompanied by morphological changes of endbulb terminals. Loss of the hair cell-specific protein otoferlin (Otof) abolishes neurotransmission in the cochlea and results in the smaller endbulb of Held terminals. Thus, peripheral hearing impairment likely also leads to alterations in the morphological synaptic vesicle (SV) pool size at individual endbulb of Held active zones (AZs). Here, we investigated endbulb AZs in pre-hearing, young, and adult wild-type and mice. During maturation, SV numbers at endbulb AZs increased in wild-type mice but were found to be reduced in mice. The SV population at a distance of 0-15 nm was most strongly affected. Finally, overall SV diameters decreased in animals during maturation.
Held终球位于前腹侧蜗神经核，是听觉通路的首个中枢突触。在发育过程中，Held终球在功能上逐渐成熟，以实现具有高时间精度的快速而强大的突触传递。这一过程伴随着Held终球终末的形态学变化。毛细胞特异性蛋白 otoferlin（Otof）的缺失会消除耳蜗中的神经传递，并导致Held终球终末变小。因此，外周听力障碍可能也会导致单个Held终球活性区（AZ）处形态学突触小泡（SV）池大小的改变。在此，我们研究了听力前、幼年和成年野生型及 小鼠的Held终球活性区。在成熟过程中，野生型小鼠Held终球活性区的突触小泡数量增加，但在 小鼠中却减少。距离为0 - 15纳米处的突触小泡群体受影响最为强烈。最后，在 动物成熟过程中，总体突触小泡直径减小。
