On the basis of ultrastructural, biochemical, cytochemical, and electro-physiological evidence, the stria vascularis, a highly vascular epithelium of the mammalian cochlea, has been implicated as one site of endolymph synthesis. It would seem natural to suspect that its highly developed counterpart in the avian cochlea, the tegmentum vasculosum (TV), might have a similar function. This study utilizes routine light and electron microscopy, biochemistry, cytochemistry, and vascular corrosion casting to describe the structure and blood supply to the (TV) in the duckling and provide evidence for its involvement in endolymph synthesis.

Four to 16 week-old ducklings (Anas platyrhyncos)were anesthetized and anticoagulated and perfused via the common carotid arteries with buffered, 2% glutaraldehyde for routine light microscopy or transmission or scanning electron microscopy, or with Mercox resin for vascular corrosion casting. Casts were macerated in 5% KOH and warm water to remove tissue, cleaned in formic acid and water, dried by lyophilization, mounted on stubs and viewed at 10-20 kv by SEM.