Lavigne-Rebillard M, Pujol R
INSERM-U. 254, Montpellier, France.
Acta Otolaryngol. 1988 May-Jun;105(5-6):398-402. doi: 10.3109/00016488809119492.
Twelve cochleas from human fetuses ranging in age from 13 to 22 gestational weeks were investigated by transmission electron microscopy in order to follow the development of hair cell innervation. First, we were able to confirm the two general gradients of cochlear maturation, i.e. 'internal-to-external' and 'base-to-apex'. In the 14th week of gestation, the inner hair cell pattern of innervation was almost mature, with well formed afferent synapses and axo-dendritic efferent contacts. At the outer hair cell level, only afferents, probably both spiral and radial ones, were present up to week 16. At week 22, axo-somatic synapses were observed between the medial efferents and the outer hair cells, but they were not yet completely mature. At this stage the myelination had begun within the spiral lamina fibres. These findings confirmed that the different stages of synaptogenesis in the human cochlea are similar to that described in other mammals, and thus the same kind of functional relationships could be proposed.
为了追踪毛细胞神经支配的发育过程，利用透射电子显微镜对12个年龄在妊娠13至22周的人类胎儿的耳蜗进行了研究。首先，我们能够证实耳蜗成熟的两个一般梯度，即“从内到外”和“从基底到顶部”。在妊娠第14周，内毛细胞的神经支配模式几乎成熟，具有形成良好的传入突触和轴突-树突传出接触。在外毛细胞水平，直到第16周只有传入神经，可能既有螺旋神经又有放射状神经。在第22周，在内侧传出神经和外毛细胞之间观察到轴突-胞体突触，但它们尚未完全成熟。在这个阶段，螺旋板纤维内已经开始有髓鞘形成。这些发现证实，人类耳蜗突触发生的不同阶段与其他哺乳动物中描述的相似，因此可以提出相同类型的功能关系。
