Multiple receptor systems promote CNS neural migration

To identify glial receptor systems in CNS migration, cerebellar granule neuron migration was assayed on glass fibers coated with polylysine, astroglial membranes (AM fibers), or the extracellular matrix proteins collagen (COLL fibers), fibronectin (FN fibers), and laminin (LAM fibers). By video microscopy, granule cells migrated along AM fibers with the cytology, neuron-fiber apposition, and dynamics seen on living glia. The demonstration that immobilized astroglial membranes support neural migration suggests that astroglial receptor systems, in combination with glial fiber geometry, promote CNS neural migration. Moreover, granule neurons migrated rapidly on LAM fibers, moved relatively slowly on FN fibers, and not at all on COLL fibers. Antibody perturbation analyses suggested that, whereas astrotactin provides the neural receptor for migration on astroglial membranes, integrin beta 1 provides the neural receptor for migration on LAM fibers. These results suggest that multiple receptor systems support CNS neural migration.