AQP4 and neuromyelitis optica: Likewise, the ependymal lining of ventricles in NMO tissue exhibited loss of ependymocytes and structural disorganization associated with the presence of subependymal reactive astrocytes, loss of AQP4 expression at both the ependymal surface and in the parenchyma, microglial reactivity, C9neo deposition, and granulocytic infiltrates at the CSF face of the ependymal layer.