Neurite outgrowth patterns in cerebellar microexplant cultures are affected by antibodies to the cell surface glycoprotein L1.

To probe for the role of the L1 cell surface glycoprotein during neurite outgrowth and fasciculation in the early postnatal mouse cerebellar cortex, a microexplant culture system was used. Fasciculation of neurites was reduced in the presence of antigen-binding fragments (Fab) of poly- and monoclonal L1 antibodies, as compared to untreated controls. In addition, speed of neurite outgrowth was enhanced in the presence of antibodies. Migration of cell bodies of small neurons was also significantly increased. Very similar effects on these outgrowth parameters were observed with Fab fragments from poly- and monoclonal neural cell adhesion molecule (N-CAM) antibodies. Antibodies from preimmune sera had no effect. These findings suggest that L1 antigen not only plays a role in adhesion of isolated neural cell bodies and migration of granule cell neurons in the early postnatal mouse cerebellar cortex (Lindner et al., 1983; Rathjen and Schachner, 1984), but also in neurite outgrowth and fasciculation.