AQP4 and neuromyelitis optica: However, 24 h after the systemic application of immunoglobulin preparations from NMOSD patients (the so-called NMO-IgGs) or recombinant human AQP4-abs into mice or rats [4, 21, 40], the antibodies were found on astrocytes in the area postrema [40], but not elsewhere in the CNS [4, 21, 40].