GFAP and Hydrocephalus: Second, morphological and functional alterations in the blood–brain barrier (BBB), disorganization of white matter architecture and vascularization, as well as hydrocephalus were reported in 18–24 month GFAP KO mice, suggesting an involvement of GFAP in the long-term maintenance of normal BBB and CNS myelination (Liedtke et al., 1996).