Contactins mediate cell surface interactions during nervous system development. Has some neurite outgrowth-promoting activity in the cerebral cortical neurons but not in hippocampal neurons (By similarity). Involved in neuronal activity in the auditory system. Interacts with PTPRG. Expressed in the nervous system. Preferentially expressed in the central auditory pathways. Specifically expressed in the postnatal nervous system, reaching a maximum level at 3 weeks postnatal. Belongs to the immunoglobulin superfamily. Contactin family.