Wang R T, Halpern M
Brain Res. 1982 Apr 8;237(1):23-39. doi: 10.1016/0006-8993(82)90555-8.
Postnatal cell proliferation, presumably for the purpose of neuronal replacement, was demonstrated in the vomeronasal epithelium of adult garter snakes using experimental vomeronasal axotomy. The luminal supporting cell layer of the epithelium did not undergo mitosis, nor necrosis, but exhibited some morphological modifications following axotomy. The bipolar layer underwent progressive irreversible degeneration following denervation. Degeneration of neurons progressed initially from alteration of cellular ultrastructure, to gross distortion of neuronal shapes followed by disintegration and disappearance of necrotic neurons. Maximal depletion of neurons occurred two weeks following surgery. The columnar epithelium at that time was characterized by the presence of a cell-depleted zone located between the luminal supporting cell layer and the basal, undifferentiated (Ud) cell layer. This cell-depleted zone occupied 70-80% of each degenerated cell column. Regeneration of axotomized neurons did not occur. The basally located, Ud cells exhibited no changes indicative of necrotic processes, but underwent active cell proliferation following axotomy. Changes in proliferative properties in the Ud cell layer were temporally related to the degeneration of the neuronal cell layer following nerve lesion. The Ud cell proliferation rate was slower than the rate of Bp cell degeneration. Proliferating Ud cells in the denervated epithelium may serve as the source of reconstituted vomeronasal bipolar neurons.
利用实验性犁鼻器轴突切断术，在成年束带蛇的犁鼻器上皮中证实了出生后细胞增殖，推测其目的是进行神经元替代。上皮的腔面支持细胞层未发生有丝分裂，也未发生坏死，但在轴突切断后出现了一些形态学改变。双极细胞层在去神经支配后经历了渐进性的不可逆变性。神经元变性最初从细胞超微结构的改变开始，发展到神经元形状的严重扭曲，随后坏死神经元解体并消失。手术后两周神经元出现最大程度的减少。此时柱状上皮的特征是在腔面支持细胞层和基底未分化（Ud）细胞层之间存在一个细胞缺失区。这个细胞缺失区占每个退化细胞柱的70 - 80%。轴突切断的神经元未发生再生。位于基底的Ud细胞未表现出坏死过程的迹象，但在轴突切断后进行了活跃的细胞增殖。Ud细胞层增殖特性的变化与神经损伤后神经元细胞层的变性在时间上相关。Ud细胞的增殖速度比双极（Bp）细胞的变性速度慢。去神经支配上皮中增殖的Ud细胞可能是重建犁鼻器双极神经元的来源。
