Disclosed are compositions relating to the Nogo receptor (NgR) family as well as fragments, chimeras, and variants thereof. The invention provides polypeptides, nucleic acids, vectors, expression systems, and antibodies and antibody fragments related to the NgRs as well as uses thereof. Such uses include modulation neurite outgrowth in a subject and treatment of central nervous system disorders in a subject, as well as, methods of identifying and screening compounds that can be used for modulating neurite outgrowth in a subject or in treatment of central nervous system disorders in a subject.