Vanický Ivo, Blaško Juraj, Tomori Zoltán, Michalová Zuzana, Székiová Eva
Institute of Neurobiology Biomedical Research Center Slovak Academy of Sciences, Šoltésovej 4, Košice 04001, Slovakia.
Institute of Experimental Physics Slovak Academy of Sciences, Watsonova 47, Košice 04001, Slovakia.
IBRO Neurosci Rep. 2024 Mar 22;16:476-484. doi: 10.1016/j.ibneur.2024.03.008. eCollection 2024 Jun.
In the rat, tail nerves are the longest peripheral nerves in their body. We suggest that ventral caudal nerve (VCN) may serve as a model for studying nerve injury and long distance regeneration. For this purpose, we have studied the anatomy and morphometry of the VCN in control animals. 10 cm long segment of the VCN was removed, and transversal sections were collected at 10 mm distances. The myelinated axons were counted, and the series of data were used to characterize the craniocaudal tapering of the nerve. In a separate group of animals, retrograde tracing with Fluorogold was used to localize and quantitate the spinal neurons projecting their axons into the VCN. After complete nerve transection, the time course of histopathological changes in the distal segment was studied. The primary goal was to define the time needed for axonal disintegration. In later periods, axonal debris removal and rearrangement of tissue elements was documented. After compression injury (axonotmesis), Wallerian degeneration was followed by spontaneous regeneration of axons. We show that the growing axons will span the 10 cm distance within 4-8 weeks. After different survival periods, the numbers of regenerating axons were counted at 10 mm distances. These data were used to characterize the dynamics of axonal regeneration during 4 months' survival period. In the present study we show that axonal regeneration across 10 cm distance can be studied and quantitatively analyzed in a small laboratory animal.
在大鼠中，尾神经是其体内最长的外周神经。我们认为腹侧尾神经（VCN）可作为研究神经损伤和长距离再生的模型。为此，我们研究了对照动物中VCN的解剖结构和形态测量学。切除10厘米长的VCN节段，并每隔10毫米收集横向切片。对有髓轴突进行计数，并将一系列数据用于描述神经的头尾逐渐变细情况。在另一组动物中，使用荧光金进行逆行追踪，以定位和定量将轴突投射到VCN中的脊髓神经元。在完全切断神经后，研究了远端节段组织病理学变化的时间进程。主要目标是确定轴突崩解所需的时间。在后期，记录了轴突碎片的清除和组织成分的重新排列。在压迫性损伤（轴突断裂）后，沃勒变性之后是轴突的自发再生。我们发现生长中的轴突将在4至8周内跨越10厘米的距离。在不同的存活期后，每隔10毫米对再生轴突的数量进行计数。这些数据用于描述4个月存活期内轴突再生的动态过程。在本研究中，我们表明在小型实验动物中可以研究并定量分析跨越10厘米距离的轴突再生。
