Tridimensional architecture of the collagen element in the arachnoid granulations in humans: a study on scanning electron microscopy

Abstract

The arachnoid granulations of adult individual of both sexes were studied through scanning electron microscopy. The dura mater and arachnoid meninges of individuals were collected at the Service of Death Verification of São Paulo - USP and fixed in Karnovsky solution. After this period the material was prepared for analysis in electron microscope. Our results demonstrated that the arachnoid granulations are formed by a pedicle, body and apex, being surrounded by a capsule of connective tissue, which in turn is composed of, basically, bundles of collagen fibers that line pores of different shapes and sizes. The smaller pores are lined by tiny bundles and are located at the apical region of the granulation and the larger are lined by thicker bundles and are located at the lateral regions. In the body we verified that the bundles of collagen fibers compose a fibrous meshwork and in some regions these bundles have circular orientation, forming pores similar to those found at the region of the capsule.

The collagenic architecture of human dura mater

“…20 The 1 N NaOH scanning elec ton microscopy investigation technique is a commonly used method to study the collagenic component of many tissues and organs in normal and pathological condi tions. 7,21,22,26,27 In terms of clinical application, this technique is quite similar to that recommended by the WHO (1992) (1 N NaOH for 1 hour at 20°C) for prion inactivation for allografts. Other techniques can be used for this purpose, such as sodium hypochlorite 2% for 1 hour at 20°C or autoclaving at 132°C for 1 hour, but NaOH maceration is chosen because it is the only technique that really pre serves the collagen structure of the allograft.…”

Histomorfometria das meninges encefálicas de ratos Wistar em diferentes faixas etárias

“…Realizamos o estudo na região do seio sagital superior, sendo importante devido à presença das granulações aracnóides, vasos sanguíneos e por localizar feixes espessos de fibras colágenas (Thompson 1984, Conegero & Chopard 2003.…”

Cerebrospinal fluid absorption disorder of arachnoid villi in a canine model of hydrocephalus

“…[50] The core of the arachnoid villi is constructed of dense networks. [51] The protein and cell deposits may obstruct the dense networks of arachnoid villi. Thus, another plausible explanation for the decreased CSF absorption by arachnoid villi in chronic hydrocephalus is the physical obstruction of the dense collagen and elastic fiber networks.…”