Led by principal investigator Harald Sontheimer, Ph.D., the Sontheimer Lab researches the biology of glial cells, the brain's most abundant cell type. Sontheimer is credited with making foundational discoveries on the functional properties of glial cells in the brain, including the localization and mechanisms of a range of receptors and ion channels that were previously thought to exist only on nerve cells. Currently, the lab studies the molecular structure and activity of glial cells in health, cancer and other diseases. He and his research team work to understand the mechanisms underpinning the functions of glial cells and how these functions may fault.
The Sontheimer lab answered a 125-year old question about the purpose of perineuronal nets that are wrapped around some neurons, and in the process uncovered a potential treatment for acquired epilepsy. Glioblastoma cancers make room to grow in the brown by emitting an excitatory chemical neurotransmitter called glutamate in excessive amounts that kills neighboring healthy cells. Sontheimer and researchers saw that glutamate targeted brain cells producing a different chemical neurotransmitter called “GABA,” that usually calms neurons by inhibiting them from firing electrical impulses once the messages are relayed. Without GABA, the brain becomes too excited and can seize. In addition to glutamate, the tumor also secretes an enzyme aimed at destroying the surrounding extracellular matrix, a gel-like substance that holds brain cells in place. That enzyme attacked the perineuronal nets. For generations, scientists believed the nets inhibited messaging. Sontheimer's lab found they enhance messaging, and when neurons lose their nets, they're more likely to seize. Understanding the role of perineuronal nets could lead researchers to discover potential pharmacological solutions.