Neurite formation of aging sensory ganglion cells

在老化背根神经节（DRG）细胞培养中，DRG细胞显示多极、双极或假单极形式。部分假单极神经元有许多细长的神经突从干突或结构样肿胀体或肾小球的交界处延伸（单极2细胞型）。在胎儿或新生小鼠DRG细胞培养物中未观察到这些结构。在无NTF或添加NT-3、NT-4或BDNF的培养液中，单极2神经元的出现率约为5%，而添加NGF的培养液中单极2神经元的出现率约为30%，各培养液中存活神经元的数量无差异。该类型细胞的出现受NGF的影响，不受其他神经营养因子的影响。提示成年DRG神经元仅保留低亲和力NGF受体（p75）而不保留高亲和力NGF受体（trk A、B或C）。

In aging dorsal root ganglion (DRG) cell culture, DRG cells display the multipolar, bipolar or pseudounipolar forms. Some pseudounipolar neurons had many thin neurites elongated from the junction of the stem process or a structure-like swelling body or glomerulus (unipolar 2 cell type). These structures were not seen in fetal or newborn mouse DRG cell cultures. Unipolar2 neurons appeared with an incidence of about 5% in a medium without NTF or supplemented with NT-3, NT-4 or BDNF.However unipolar2 neurons increased about 30% in a medium supplemented with NGF.There is no difference of the number of surviving neurons in each of culture medium. The appearance of this type cell was affected by NGF, not affect other neurotrophic factors. It is suggested that adult DRG neurons remained only the low-affinity NGF-receptor(p75) but not the high-affinity NGF receptors(trk A, B, or C).