Perfusion of particles through arachnoid villi of the monkey

Abstract

By the perfusion of arachnoid villi in excised simian dura mater, the passage through the villi of colloidal gold (.2–.3 µ diam), polystyrene microspheres of 1.17 µ and 1.8 µ, yeast (3–6 µ), goat erythrocytes (4 µ) and monkey erythrocytes (7.5 µ) was demonstrated. Polystyrene microspheres in the 6.4–12.8-µ range were excluded from passage. During the perfusion of the particles an impedance to flow most often developed and the particles were demonstrated by later microscopic examination to be enmeshed in the villi. Upon perfusion of mixtures of various sizes there was not found to be discrimination in passage based on size as long as the particles were beneath threshold size. It is concluded that these observations confirm the surmise, made earlier on anatomical evidence, that the villi provide open communication between the meninges and the venous system.