Matsunaga T, Kanzaki J, Ogawa Y, Hosoda Y
Department of Otolaryngology, School of Medicine, Keio University, Tokyo, Japan.
Auris Nasus Larynx. 1994;21(2):90-7. doi: 10.1016/s0385-8146(12)80026-5.
To investigate the central-peripheral transitional region (TR) of the eighth nerve in elderly humans and to determine the reasons for its fragility, the eighth nerve root was studied by light and electron microscopy and by immunohistochemistry. Central and peripheral nervous tissue showed complex interdigitations at the TR. Slight proliferation of central glial tissue accompanied with disarranged course of the nerve fibers was also seen in this region. These findings were though to be age-related changes of the eight nerve. The capillaries ran in various directions at the TR and formed anastomoses with capillaries in the peripheral portion of the nerve. The density of capillaries in the peripheral nervous tissue was twice as high as that in the central nervous tissue. These findings indicated that the capillaries at the TR provide a connection between the blood supply to the central and peripheral portions of the eighth nerve. The occurrence of the age-related changes and complex course of the capillaries at the eighth nerve TR appeared to be related with the fragility of this region.
为研究老年人第八神经的中枢-外周过渡区（TR）并确定其脆弱性的原因，采用光镜、电镜及免疫组化方法对第八神经根进行了研究。中枢和外周神经组织在TR处呈现复杂的相互交错。在该区域还可见中枢神经胶质组织轻度增生并伴有神经纤维走行紊乱。这些发现被认为是第八神经的年龄相关变化。毛细血管在TR处向各个方向走行，并与神经外周部分的毛细血管形成吻合。外周神经组织中的毛细血管密度是中枢神经组织的两倍。这些发现表明，TR处的毛细血管为第八神经中枢和外周部分的血液供应提供了连接。第八神经TR处年龄相关变化的发生及毛细血管的复杂走行似乎与该区域的脆弱性有关。
