© 2017 Elsevier Inc. All rights reserved. Neurodegenerative disorders are marked by the loss of neurons within the brain and/or spinal cord. The clinical features of this diverse group of neurological disorders depend on the particular central nervous system regions involved. The two most common neurodegenerative disorders are Alzheimer's disease and Parkinson's disease. With the aging of the general population, the prevalence of these disorders is expected to rise dramatically in the next few decades, with a resultant increase in the societal and financial burden of these disorders. Currently, medications for this group of disorders are limited and aim to treat the symptoms only. None of the currently available therapies slow or stop the continued loss of neurons. A better understanding of the mechanisms underlying neurodegeneration should lead to more effective, disease-modifying treatments in the future.