Erlich S S, McComb J G, Hyman S, Weiss M H
J Neurosurg. 1986 Mar;64(3):466-73. doi: 10.3171/jns.1986.64.3.0466.
Previous physiological studies indicate that the olfactory region serves as a major pathway for cerebrospinal fluid (CSF) drainage into the lymphatic system. The present study was undertaken to determine the ultrastructural characteristics of this egress route. New Zealand White rabbits received a single bolus injection of the tracer ferritin (MW 400,000) into both lateral ventricles in such a manner as not to raise the intraventricular pressure above the normal level. The animals were sacrificed via intracardiac perfusion of fixative between less than 12 minutes and 4 hours following injection. The cribriform region was removed en bloc, decalcified, sectioned coronally, and prepared for light and electron microscopic examination. The arachnoid, dura, and periosteum surrounding the fila olfactoria passing through the cribriform plate merge together and form the perineurium, which consists of multiple layers of loosely overlapping cells with widely separated junctions and few vesicles. The perineurium surrounding the olfactory filaments at the superficial submucosal level is only one cell thick. The subarachnoid space freely communicates with the perineural space surrounding each filament. No morphological barrier between the perineural space and the loose submucosal connective tissue was identified. Whether or not the perineurium was multi- or single-layered, ferritin was noted in abundance between the loosely overlapping perineural cells and in the submucosal connective tissue. The distribution of ferritin at 12 minutes was similar to that at 4 hours; however, the quantity of ferritin was increased at 4 hours. These results indicate that no significant barrier to CSF drainage is present at the rabbit cribriform region and that CSF reaches the submucosal region rapidly via open pathways.
先前的生理学研究表明，嗅觉区域是脑脊液（CSF）排入淋巴系统的主要途径。本研究旨在确定该排出途径的超微结构特征。给新西兰白兔双侧侧脑室单次注射示踪剂铁蛋白（分子量400,000），注射方式不会使脑室内压升高至正常水平以上。在注射后不到12分钟至4小时之间，通过心脏内灌注固定剂处死动物。将筛状区域整块切除，脱钙，冠状切片，并准备进行光镜和电镜检查。穿过筛板的嗅丝周围的蛛网膜、硬脑膜和骨膜融合在一起形成神经束膜，神经束膜由多层松散重叠的细胞组成，细胞间连接广泛分离且很少有小泡。黏膜下浅层水平的嗅丝周围的神经束膜仅一层细胞厚。蛛网膜下腔与每根嗅丝周围的神经周隙自由相通。未发现神经周隙与疏松的黏膜下结缔组织之间存在形态学屏障。无论神经束膜是多层还是单层，在松散重叠的神经周细胞之间以及黏膜下结缔组织中都发现大量铁蛋白。12分钟时铁蛋白的分布与4小时时相似；然而，4小时时铁蛋白的量增加。这些结果表明，兔筛状区域对脑脊液引流不存在显著屏障，脑脊液通过开放途径迅速到达黏膜下区域。
