Glial cells are involved with both brain health and disease. Diseases of glia (e.g., demyelinating diseases) are also neurodegenerative. When glial cells die in diseases such as multiple sclerosis, often their neural partners die, as well. Glia are involved in both beneficial and detrimental ways in neurodegenerative diseases such as Parkinson’s amyotrophic lateral sclerosis, and Alzheimer’s. Sometimes glia are the targets of infectious organisms (e.g., HIV/AIDS, mad cow disease). (Fields, R. Douglas, PhD. The Other Brain. p 65-67. NY: Simon & Schuster, 2009.)