GAD2 and deafness: Acquired deafness was linked with enhanced glutamatergic transmission, as shown in the superior olivocochlear complex or the midbrain (Potashner et al., 1997), with reduced glycinergic inhibition (Suneja et al., 1998; Potashner et al., 2000) or with decreases in GAD65 (Milbrandt et al., 2000).