The role of selenium in neurodegenerative diseases

Selenium is an essential micronutrient, imparting a biological function as a key component of the 21st amino acid, selenocysteine. To date, 25 selenoproteins have been discovered within the human proteome, which can be classified according to a range of functions. Although these proteins are in low abundance in the brain, studies have reported their relevance to normal neurological function, primarily due to antioxidant activity and mechanisms that modulate mitochondrial function. Selenium has also been identified as playing a role in several neurodegenerative disorders, including Alzheimer's and Parkinson's disease, and recent research has suggested possible association with other diseases as multiple sclerosis, amyotrophic lateral sclerosis, and Huntington's disease. This chapter will discuss the emerging role of selenium in neurodegenerative processes, highlighting the rapidly growing interest in this often-overlooked essential element.