George J. Dohrmann

The choroid plexus: A historical review

Summary The embryology, macroscopic structure, microscopic structure, fine structure, function and pathology of the choroid plexus were reviewed. Conflicting opinions have been noted and selected critical comments expressed.

Dark and light epithelial cells in the choroid plexus of mammals

Dark and light cells were observed in the epithelium of mammalian choroid plexus fixed with glutaraldehyde and/or osmium using immersion or perfusion techniques. Previous studies interpreted dark and light cells in various tissues as artifacts of poor fixative penetration when tissue was fixed by immersion. Since choroidal villi consisted of a single layer of epithelial cells directly overlying a capillary core, the appearance of dark and light choroidal epithelial cells was probably not due to degree or rate of fixative penetration. It was concluded that the dark and light cells of the choroidal epithelium, which appeared fine structurally similar to one another, might represent varying states of cellular hydration at the time of fixation.

Lobated nuclei in epithelial cells of the choroid plexus of young mice

Lobated nuclei were observed in the choroid plexus epithelial cells of young (12 weeks) mice whereas only small invaginations were present in aging (52 weeks) mice. Cytoplasm between the nuclear lobes contained a high concentration of rough endoplasmic reticulum and polyribosomes. We concluded that the striking lobation and high concentration of rough endoplasmic reticulum and polyribosomes in the interlobar cytoplasm were reflections of a greater nucleocytoplasmic interaction in the young mice.

Demonstration of the Microvasculature of the Spinal Cord by Intravenous Injection of the Fluorescent Dye, Thioflavine S

In the past, thioflavine S has been used for visualizing blood vessels and patterns of blood flow (Schlegel 1949; Schlegel and Moses 1950; Oliver et al. 1951). Methods employed have involved an intravenous injection of the dye, immersion of hand-cut sections in glycerol and examination of sections under incident Woods light. With improved techniques it is possible to obtain microtome-cut sections and to use a more intense light source for enhancing fluorescence and resulting visualization of small vessels. Occlusion of arterioles by undissolved dye particles is prevented by ultracentrifugation of the solution to be injected.

Fine structural studies of capillaries in nzb/nzw mice.

Abstract The fine structure of capillaries in young (12 weeks) and aging (40–52 weeks) NZB NZW F1 mice, using Strong A mice of the same sex and similar ages as controls, was studied. Electron dense deposits and irregularly thickened basement membranes were noted in glomerular capillaries of the aging NZB NZW mice. Irregular thickening of the basement membranes was present in the choroidal capillaries of aging NZB NZW mice, but electron dense deposits were not seen. Myocardial capillaries in aging mice of both strains contained an increased number of pinocytotic vesicles.