Ulex europeus agglutinin I binds exclusively to primary olfactory neurons in the rat nervous system.

Lectin binding histochemistry was used to investigate the distribution of binding sites for the fucose-selective lectin Ulex europeus agglutinin I in the rat nervous system. It was found that this lectin bound exclusively to a surface membrane component, probably a glycoprotein, on primary olfactory and vomeronasal sensory neurons, and to no other structure in the nervous system. A similar pattern of Ulex europeus agglutinin I binding was found in adult, immature and embryonic rats. Binding was also demonstrated on olfactory axons regenerating through a peripheral nerve graft. Three other lectins, including another fucose-selective lectin, and the N-acetyl galactosamine-binding soybean lectin failed to show similar exclusive binding. The presence of a specific surface glycoconjugate solely on olfactory neurons suggests that the molecule may play some role in development or maintenance of organization of this neuronal pathway.