NTNRα, NTNRα extracellular domain (ECD), NTNRα variants, chimeric NTNRα (e.g., NTNRα immunoadhesion), and antibodies which bind thereto (including agonist and neutralizing antibodies) are disclosed. Various uses for these molecules are described, including methods to modulate cell activity and survival by response to NTNRα-ligands, for example NTN, by providing NTNRα to the cell.