Cytology of the normal and abnormal choroid plexi in selected domestic mammals, wildlife species, and man.

The research article presents a cytologic study on the choroid plexi in various animals and humans to better understand cellular changes in cerebrospinal fluid during disease. The study evaluated a total of 756 cytologic imprints from species including dogs, horses, cattle, monkeys, and humans, both healthy and with various abnormalities.

Sampling and Impression Smears

• The researchers collected samples from 11 dogs, 10 horses, 1 mule, 3 cattle, 1 sheep, 2 pigs, 1 deer, 4 monkeys, and 7 humans.
• The majority of these samples came from individuals free of neurologic disease, with some cases of abnormalities as well.
• The human samples included one individual with mild neurologic signs and others who had passed away with no history of neurologic disease but showed characteristics such as arteriosclerosis on further examination.
• Cytologic imprints (impressions smears) of the choroid plexi, structures in the brain responsible for producing cerebrospinal fluid, were studied to identify cellular changes that occur in the case of disease.

Cell Types and Morphology

• Through their study, the researchers identified four different cell types which were consistently present in all the species examined.
• These cell types, named alpha, beta, and gamma (or vesicle-bearing), displayed distinct characteristics such as the color and pH of their cytoplasm.
• The alpha cells had a deeply basophilic (blue staining) cytoplasm, beta cells had neutral to weakly acidophilic (acid-staining) cytoplasm, and gamma cells bore unique inclusions, or vesicles, filled with tiny light tan to pale pink granules.
• The fourth type of cell identified was the Kolmer cell, which was present in very low numbers.
• Immature lymphocytes, a type of white blood cell, were also detected in newborn foals, a pig, and in a stillborn calf and deer.

Research Findings and Implications

• The findings suggest that the choroid plexi contain more than one type of epithelial cell.
• This indicates that our knowledge of their morphology is not yet complete, as other unusual cells and structures were also found in small quantities.
• The researchers found that imprints are highly effective for studying the choroid plexi, allowing for the detection of minute changes not visible in conventional hematoxylin and eosin sections used in histopathology.