目的　探讨第四脑室外侧孔与外侧隐窝之间的室底结构扫描电镜观察特点。　方法　将 34只正常雄性SD大鼠分为幼年、成年及老年 3组 (2周龄～ 10 8周龄 ) ,以扫描电镜术对上述区域进行观察。　结果　在外侧孔与外侧隐窝之间的室底区为一少纤毛区 ,但有较丰富的室管膜上结构 :1 有两种室管膜上纤维 ,一种纤维位于纤毛上方 ,常粘合成纤维索 ,交织成纤维网 ;另一种纤维穿行于纤毛簇之间 ,紧贴室管膜细胞表面 ;纤维之间不粘合也不交织成网 ,单根纤维清晰可见 ,全长粗细基本一致。 2 室管膜上细胞可见 2种类型 ,1种为吞噬细胞样细胞 ,位于纤毛簇上方 ;另一种为神经元样细胞 ,紧贴于室管膜细胞表面上。 3 与幼年和成年动物相比 ,老年大鼠室管膜细胞的纤毛和微绒毛明显减少 ,而室管膜上结构明显增多。　结论　该区符合室周器官扫描电镜观察特点 ,其室管膜上结构随加龄而增多 Objective To investigate the scanning electron microscopic observation of the floor structure between the lateral ventricle and the lateral recess of the fourth ventricle. Methods Thirty-four male Sprague-Dawley rats were divided into 3 groups (2 weeks to 108 weeks old). The above regions were observed by scanning electron microscopy. Results The lateral ventricular zone between the lateral and lateral crypts was a ciliated area with abundant ependymal structures: 1 There were two types of ependymal fibers, one above the cilia and often sticky Synthetic fiber cord, interwoven into a fiber network; another fiber through the ciliated tufts, close to the ependymal cell surface; fiber is not interwoven between the mesh, the single fiber is clearly visible, the total length of the thickness Basically the same. There are 2 types of cells found on the ependymal membrane, one is a phagocyte-like cell located above the ciliated tufts, and the other is a neuron-like cell clinging to the ependymal cell surface. Compared with juvenile and adult animals, the cilia and microvilli of the ependymal cells of the aged rats were significantly reduced, whereas the structures of the ependymal membrane were significantly increased. Conclusions This area accords with the characteristics of perimembranous organ scanning electron microscopy. The structure of ependymal membrane increases with aging