Contactins mediate cell surface interactions during nervous system development. Participates in oligodendrocytes generation by acting as a ligand of NOTCH1. Its association with NOTCH1 promotes NOTCH1 activation through the released notch intracellular domain (NICD) and subsequent translocation to the nucleus. May be involved in motor coordination. Interacts with PTPRG. Specifically expressed in neuronal cells. In brain, it is expressed in spinal cord, cerebrum and cerebellum. At E17, it is expressed hippocampus, cerebellum, and the brain stem. Strongly expressed after birth with a maximum level between postnatal day 1 and 21, which corresponds to the time frame of oligodendrogliogenesis. Expressed at low level during embryogenesis. Highly expressed after birth. Belongs to the immunoglobulin superfamily. Contactin family.