Illustration of a fragment antigen-binding (Fab) region (red) of an autoimmune antibody bound to a GABA A (gamma aminobutyric acid-A) receptor. Autoimmune antibodies recognise an organism's own cells, rather than foreign cells. GABA receptors are found in the nervous system, where they have an inhibitory effect. Binding of antibodies to the GABA A receptor inhibit their function causing hyperexcitability. This leads to Anti-GABA A receptor encephalitis, an inflammatory brain disease that causes frequent seizure and behavioural abnormalities.