PDF(Pubmed)
Abstract：
Based on the auditory periphery and the small head size, Etruscan shrews (Suncus etruscus) approximate ancestral mammalian conditions. The auditory brainstem in this insectivore has not been investigated. Using labelling techniques, we assessed the structures of their superior olivary complex (SOC) and the nuclei of the lateral lemniscus (NLL). There, we identified the position of the major nuclei, their input pattern, transmitter content, expression of calcium binding proteins (CaBPs) and two voltage-gated ion channels. The most prominent SOC structures were the medial nucleus of the trapezoid body (MNTB), the lateral nucleus of the trapezoid body (LNTB), the lateral superior olive (LSO) and the superior paraolivary nucleus (SPN). In the NLL, the ventral (VNLL), a specific ventrolateral VNLL (VNLLvl) cell population, the intermediate (INLL) and dorsal (DNLL) nucleus, as well as the inferior colliculus\'s central aspect were discerned. INLL and VNLL were clearly separated by the differential distribution of various marker proteins. Most labelled proteins showed expression patterns comparable to rodents. However, SPN neurons were glycinergic and not GABAergic and the overall CaBPs expression was low. Next to the characterisation of the Etruscan shrew\'s auditory brainstem, our work identifies conserved nuclei and indicates variable structures in a species that approximates ancestral conditions.
摘要：
根据听觉外围和小头部尺寸，伊特鲁里亚（Suncusetruscus）近似祖先哺乳动物条件。这种食虫动物的听觉脑干尚未得到研究。使用贴标技术，我们评估了它们的上橄榄复合体（SOC）的结构和外侧圆心（NLL）的核。在那里,我们确定了主要原子核的位置，他们的输入模式，发射机内容，钙结合蛋白（CaBPs）和两个电压门控离子通道的表达。最突出的SOC结构是梯形体（MNTB）的内侧核，梯形体（LNTB）的外侧核，外侧上橄榄（LSO）和上旁橄榄核（SPN）。在NLL中，腹侧（VNLL），特定的腹外侧VNLL（VNLLvl）细胞群，中间（INLL）和背侧（DNLL）核，以及下丘的中央方面被辨别。INLL和VNLL通过各种标记蛋白的差异分布而清楚地分离。大多数标记的蛋白质显示与啮齿动物相当的表达模式。然而,SPN神经元是甘氨酸能的，而不是GABA能的，并且整体CaBP表达较低。在伊特鲁里亚人听觉脑干的特征旁边,我们的工作确定了保守的原子核，并指出了接近祖先条件的物种中的可变结构。
