衰老对大鼠盆神经有髓和无髓纤维数量、大小及传导速度的影响。

Effects of aging on numbers, sizes and conduction velocities of myelinated and unmyelinated fibers of the pelvic nerve in rats.

作者信息

Nakayama H, Noda K, Hotta H, Ohsawa H, Hosoya Y

机构信息

Department of the Autonomic Nervous System, Tokyo Metropolitan Institute of Gerontology, Japan.

出版信息

J Auton Nerv Syst. 1998 Apr 30;69(2-3):148-55. doi: 10.1016/s0165-1838(98)00013-7.

DOI:10.1016/s0165-1838(98)00013-7

PMID:9696271

Abstract

The effects of aging on the conduction velocities, numbers and sizes of the myelinated and unmyelinated fibers of the pelvic nerve in Wistar rats, aged 3-9 and 30-37 months were examined using electrophysiological and ultrastructural techniques. The myelinated fibers did not show significant age-related changes in the maximum conduction velocities (9.7 +/- 1.1 m/s in adult vs. 11.0 +/- 1.5 m/s in aged rats), the number of fibers (662 +/- 27 vs. 625 +/- 56) and distribution of fiber diameters. In aged rats, the unmyelinated fibers did not show a significant change in maximum conduction velocity (1.5 +/- 0.1 m/s vs. 1.5 +/- 0.1 m/s), but showed a significant decrease in the number of fibers (4133 +/- 114 vs. 3113 +/- 456), specifically of fibers smaller than 0.7 microm in diameter. It is concluded that myelinated fibers of the pelvic nerve in rats preserve their conduction ability and fiber population during aging, but unmyelinated fibers, particularly fibers with smaller diameters decrease in number. Unmyelinated fibers with larger diameters maintain their conduction ability and numbers with aging.

摘要

采用电生理和超微结构技术，研究了3 - 9月龄和30 - 37月龄Wistar大鼠盆腔神经中髓鞘化和无髓鞘化纤维的传导速度、数量及大小随年龄增长的变化情况。髓鞘化纤维在最大传导速度（成年大鼠为9.7±1.1 m/s，老年大鼠为11.0±1.5 m/s）、纤维数量（662±27 vs. 625±56）及纤维直径分布方面未表现出与年龄相关的显著变化。在老年大鼠中，无髓鞘化纤维的最大传导速度未发生显著变化（1.5±0.1 m/s vs. 1.5±0.1 m/s），但纤维数量显著减少（4133±114 vs. 3113±456），尤其是直径小于0.7微米的纤维。研究得出结论，大鼠盆腔神经的髓鞘化纤维在衰老过程中保留其传导能力和纤维数量，但无髓鞘化纤维，特别是直径较小的纤维数量减少。直径较大的无髓鞘化纤维在衰老过程中保持其传导能力和数量。