The invention discloses a family of neuronal migration-inducing, proliferation-promoting and neurite outgrowth promoting factors, termed NRP compounds, and provides compositions and methods for the use of NRP compounds in the treatment of brain injury and neurodegenerative disease. NRP-1 compounds induce neurons and neuroblasts to proliferate and migrate into areas of damage caused by acute brain injury or chronic neurodegenerative disease, such as stroke, trauma, nervous system infections, demyelinating diseases, dimentias, and metabolic disorders. NRP compounds may be administered directly to a subject or to a subjects cells by a variety of means including orally, introperitoneally, intravascularly, and directly into the nervous system of a patient.