AQP4 and neuromyelitis optica: In addition, Ratelade et al. injected 2 μg of AQP4-IgG and 3 μL of 20% human complement in 8 μL of PBS intracerebrally into the brain of mice [1], and Zhang and Verkman induced demyelinating NMO lesions by continuous and chronic intracerebral infusion of NMO-IgG and complement in the lateral brain of mice [6].