HISTOCHEMICAL DETECTION OF GLYCOGEN AND GLYCOCONJUGATES IN THE INNER-EAR WITH MODIFIED CONCANAVALIN-A HORSERADISH-PEROXIDASE PROCEDURES

Inner ears from neonatal and adult Mongolian gerbils were examined to determine developmental changes in the content of glycogen and glycoco njugates as shown by histochemical application of the jack bean lectin , concanavalin A (con A). Sections of fixed paraffin-embedded inner ea rs were stained using the con A-horseradish peroxidase sequence in con junction with prior treatments including periodate oxidation with or w ithout subsequent reduction and diastase digestion. In adult inner ear , brief periodate oxidation followed by reduction and con A-horseradis h peroxidase staining demonstrated abundant glycogen in Deiters' cells and in fibrocytes of the spiral ligament and submacular plaque. This procedure also detected diastase-resistant glycoprotein, probably cont aining N-linked complex-type saccharides, in the basal and marginal re gions of the tectorial membrane and in the otolithic membrane. During morphogenesis and maturation, various cochlear cells showed changes in their glycogen content possibly related to stage-specific energy requ irements. Cellular glycogen storage reached adult levels by postnatal day 14. The tectorial membrane gradually acquired con A reactivity dur ing the first postnatal week. Thus, application of modified con A stai ning procedures has provided further knowledge for comparison with dat a from previous biochemical and histochemical studies of carbohydrate- rich components in the inner ear.