Growth of olfactory epithelial tissue in vitro: lectin staining of axons

In vitro methods have been used to study several aspects of development of olfactory epithelium. In this paper, the value of growing olfactory tissue in explant cultures is reviewed and some experiments are reported on the identification of lectin receptors on olfactory axons by the use of lectin-gold complexes. Both concanavalin A-gold (con A-gold) and wheat germ agglutinin-gold consistently decorated olfactory axons in explant cultures. Con A-gold also bound to the tips of growth cone filopodia, suggesting the glycoconjugate molecules containing alpha-methyl-pyranoside are important in adherence of growth cones to their substrate. The wide range in density of lectin-gold particles suggested that axons, and the sensory cells from which they arise, are not a uniform population, i.e., they have different molecular fingerprints. This was supported by the observation that soybean agglutinin-gold stained some axons very well, but others remained unstained. Peanut agglutinin did not bind to any axons.