Allen D J, Low F N
J Comp Neurol. 1975 Jun 15;161(4):515-39. doi: 10.1002/cne.901610404.
Young dogs were anesthetized by intrathoracic injection of sodium pentobarbital and perfused with buffered aldehydes. Lining tissue samples from the cranial subarachnoid space were prepared for scanning electron microscopy (SEM) by postfixing in buffered OSO4. Samples were then dehydrated, dried in a Critical Point Drying System, and coated with carbon and palladium-gold. Specimens were viewed in a Cambridge S4 scanning electron microscope. After thorough scanning, selected samples were routinely prepared for transmission electron microscopy (TEM) and viewed in a Philips EM-200 transmission electron microscope. This study depicts the surface morphology of the meningeal linings of the cranial subarachnoid space. The cranial pia mater possesses natural gaps or fenestrations between cells. SEM reveals a more complex morphology of arachnoid trabeculae than previously interpreted from light and transmission electron microscopy. Many free cells are observed on the meningeal linings of the subarachnoid space. The present study establishes that these free cells are macrophages by means of definitive TEM correlates. Microvillous-like processes extending between macrophages and the pial surface are present. The frequency and the nature of these thin processes suggest the possibility of a plasmalemma-mediated system of communication.
幼龄犬经胸腔注射戊巴比妥钠麻醉后，用缓冲醛类进行灌注。取自颅蛛网膜下腔的衬里组织样本，通过在缓冲的四氧化锇中后固定，制备用于扫描电子显微镜（SEM）观察。然后将样本脱水，在临界点干燥系统中干燥，并进行碳和钯 - 金镀膜。样本在剑桥S4扫描电子显微镜下观察。经过全面扫描后，选取的样本按常规制备用于透射电子显微镜（TEM）观察，并在飞利浦EM - 200透射电子显微镜下观察。本研究描绘了颅蛛网膜下腔脑膜衬里的表面形态。颅软脑膜细胞之间存在天然间隙或小孔。扫描电子显微镜显示蛛网膜小梁的形态比先前光镜和透射电子显微镜所解释的更为复杂。在蛛网膜下腔的脑膜衬里上观察到许多游离细胞。本研究通过明确的透射电子显微镜相关证据确定这些游离细胞为巨噬细胞。巨噬细胞与软脑膜表面之间存在类似微绒毛的突起。这些细突起的频率和性质提示存在通过质膜介导的通讯系统的可能性。
