Scarfone E, Demêmes D, Sans A
INSERM U 254, Laboratoire de Neurophysiologie Sensorielle, Montpellier, France.
J Neurosci. 1991 May;11(5):1173-81. doi: 10.1523/JNEUROSCI.11-05-01173.1991.
Synapsin I and Synaptophysin are selectively localized in axonal endings of CNS neurons where they are associated with small synaptic vesicle membranes. The development of expression of these 2 proteins was studied by immunocytochemistry during ontogenesis of the peripheral vestibular system in the mouse. Both proteins are localized in vestibular ganglion neurons and in their peripheral sensory extensions as early as gestational day 14. While the entire periphery of these fibers is labeled during embryogenesis, both proteins are subject to relocation during the postnatal maturation of these fibers. In the mature vestibular receptors they disappear from the fibers themselves but are found concentrated in their intraepithelial endings and in the neuronal cell body. These observations show that the distribution pattern of Synapsin I and Synaptophysin in peripheral extensions of vestibular afferent neurons during development is identical to that described in axonal processes of CNS neurons. This suggests that the peripheral processes of the vestibular afferent neurons present structural and biochemical characteristics of axons. These characteristics are consistent with a bimodal sensory and secretory function of mature endings.
突触素I和突触囊泡蛋白选择性地定位于中枢神经系统神经元的轴突末端，在那里它们与小突触囊泡膜相关联。通过免疫细胞化学方法，研究了这两种蛋白质在小鼠外周前庭系统个体发育过程中的表达情况。早在妊娠第14天，这两种蛋白质就定位于前庭神经节神经元及其外周感觉延伸部分。在胚胎发育期间，这些纤维的整个外周都有标记，但在这些纤维出生后的成熟过程中，这两种蛋白质都会重新定位。在成熟的前庭感受器中，它们从纤维本身消失，但集中在内皮内末梢和神经元细胞体中。这些观察结果表明，发育过程中突触素I和突触囊泡蛋白在前庭传入神经元外周延伸部分的分布模式与中枢神经系统神经元轴突过程中所描述的相同。这表明前庭传入神经元的外周过程呈现出轴突的结构和生化特征。这些特征与成熟末梢的双峰感觉和分泌功能一致。
