Cell adhesion protein that promotes the attachment of spinal cord and sensory neuron cells and the outgrowth of neurites in vitro. May contribute to the growth and guidance of axons in both the spinal cord and the PNS (By similarity). Somite-derived spondin 1 is an inhibitory signal involved in patterning the segmental migration of neural crest cells and their topographical segregation within the rostral somites in vitro. May be required to prevent the lateral drifting of the commissural axons after having crossed the floor plate.