Matsuda S, Kobayashi N, Mominoki K, Wakisaka H, Mori M, Murakami S
Department of Anatomy, Ehime University School of Medicine.
Kaibogaku Zasshi. 1998 Dec;73(6):603-13.
Sensory ganglion neurons in higher vertebrates are unique in that they are pseudounipolar with a single stem process that divides at some distance from the cell body into central and peripheral processes. In the early stages of development, these neurons are bipolar but later they became pseudounipolar. This developmental process of sensory ganglion neurons with satellite cells was examined by scanning electron microscopy following removal of connective tissue. This pseudo-unipolarization began earlier but proceeded at a slower rate in chick than in rat embryos. This difference may due to the difference found in the extent and intimacy of satellite cell investments in these two animals, which was due to the fact that sensory neurons undergo pseudo-unipolarization only in the presence of satellite cells in vitro. The neuronal perikaryal projections were observed by scanning electron microscopy after removal of connective tissue and satellite cells. Morphometric analysis reveal that perikaryal projections were more numerous on the surface of mature pseudounipolar neurons than on the surface of premature bipolar neurons, and that the number of projections increased as the neuronal cell bodies grew larger. This may support the hypothesis that perikaryal projections are structural devices for increasing the neuron-satellite interface and for improving the efficiency of metabolic exchange between these two cell types. These results suggest that satellite cells play an important role in neuronal maturation.
高等脊椎动物的感觉神经节神经元具有独特性，它们是假单极的，有一个单一的主干突起，该突起在离细胞体一定距离处分为中枢突和外周突。在发育早期，这些神经元是双极的，但后来变成了假单极。在去除结缔组织后，通过扫描电子显微镜检查了感觉神经节神经元与卫星细胞的这种发育过程。这种假单极化在鸡胚胎中开始得更早，但进展速度比大鼠胚胎慢。这种差异可能是由于在这两种动物中卫星细胞包绕的程度和紧密程度不同，这是因为感觉神经元仅在体外有卫星细胞存在时才会发生假单极化。在去除结缔组织和卫星细胞后，通过扫描电子显微镜观察神经元胞体的突起。形态计量分析表明，成熟假单极神经元表面的胞体突起比未成熟双极神经元表面的更多，并且随着神经元细胞体变大，突起的数量增加。这可能支持这样一种假说，即胞体突起是增加神经元 - 卫星细胞界面以及提高这两种细胞类型之间代谢交换效率的结构装置。这些结果表明卫星细胞在神经元成熟过程中起重要作用。
