A scanning electron microscopic observation of the choroid plexus in rats.

Abstract

Scanning electron microscopy of the choroid plexus in white rats gave the following results:1. The choroid plexus consists of tortuous capillary blood vessels, an epithelial cell layer uninterruptedly covering their surface and the interjacent connective tissue which is not seen from the surface. The contour of each epithelial cell is recognizable from the ventricular surface as a low, round hill.2. Each epithelial cell has numerous microvilli on its free surface. They are neither branched nor fused; they are variable in shape, sometimes with a swollen tip. Their thickness is inconstant even in a single microvillus. The distribution of microvilli seems more dense and conglomerated at the top of the hill than at the periphery of the cell.3. Clusters of longer protrusions which possibly correspond to groups of cilia are scattered on the epithelial surface covered with microvilli. A cluster which consists of about ten or less cilia is seen in only one per several cells. Occasionally two or three such clusters occur on a single cell.