Lichtgedanken 05

Rubrik 28 The autobiography of Canadian jour- nalist Susannah Cahalan was published under the title »Brain on Fire« and the film based on the book was later relea- sed with the same name. Critics were not overly impressed with the film, but it did serve to bring the disease—a rare, autoimmune-related brain inflammati- on known for a decade—into the pub- lic eye. Triggered by certain tumours or viral infections, antibodies are produced which attack neurotransmitter receptors in the central nervous system. In Sus- annah Cahalan’s case these antibodies attacked the NDMA receptor which Brain on fire Back in 2016, the film »Brain on Fire« brought a disease, previously hardly known, into the public eye: an autoimmune-related brain inflam- mation with the complicated name anti-NMDA receptor encephalitis. This rare disease leads to symptoms such as respiratory disorders and delusions, and is still hard to diagnose to this day. A team of Ger- man and Spanish scientists working, with Jena neurologist Prof. Dr Christian Geis, has now been able to explain the essential molecular mechanisms of the disease. BY UTA VON DER GÖNNA led to confusion, psychosis, coma, and respiratory disorders. »NDMA« stands for N-methyl D-aspartate. This subs- tance binds specifically to this receptor. Neurology has since discovered a whole range of different subtypes of these au- toimmune brain inflammations, which see the immune system attack a receptor on nerve cells. A research group from Jena, Barcelo- na, Würzburg, and Leipzig has now been able to explain the mechanisms of the autoimmune disease, in which the AMPA receptor becomes the target. »AMPA« is the abbreviation for α -ami- no-3-hydroxy-5-methyl-4-isoxazolepro- pionic acid. Like the NDMA receptor, the AMPA receptor is one of the gluta- matergic receptors and controls the transmission of nerve impulses in the brain; as such, it is vital for learning and memory processes. »Affected patients suffer from seizures, confusion, memo- ry impairment, and personality chan- ges«, explains Prof. Dr Christian Geis, a neurologist at the University Hospital and senior author of the study, the sym- ptoms of the disease. Using antibodies from patient samples In order to conduct their research, the researchers used antibodies having been acquired from patient samples. The- se antibodies are specifically directed against a subunit of the AMPA receptor, which is vital for the electrical proper- ties of the receptor. Receptors with this subunit are largely located in the synap- ses—the point of contact between two nerve cells—and are indispensible for the rapid transmission of impulses bet- ween the nerve cells.