Physical effects of the choroid plexus on the cochlear nuclei in man.
Relatively deep invaginations on the surface of the dorsal cochlear nucleus (DCN) inside the fourth ventricle lateral recess were observed just below the choroid plexus. The ependymal cells and neurons in the affected areas of the DCN manifest coarse inclusions in their cytoplasm. The inclusions are rounded granules, approximately 2 micron in diameter, relatively evenly spread through cytoplasm of these cells. The inclusions are not lipofuscin or known, non-viral cytoplasmic bodies specific for certain diseases accompanied by degeneration of the nervous tissue. The inclusions are, however, observed in cells with relatively high lipofuscin content. The change in transportation of the nutrients and metabolites between the affected areas in the DCN, cerebrospinal fluid, and capillaries as well as metabolic impairments in the DCN may be a reason for the observed accumulation of inclusions and lipofuscin. These pathological changes may also be a reason for certain hearing disorders.