Astrocytic reaction to perinatal brain damage, which is caused by 
hyperammonemia, liver disease, hyperbilirubinemia, and a few other conditions, 
was studied using immunohistochemical methods for the demonstration of glial 
fibrillary acidic protein (GFAP). We found no increase in GFAP expression in 
those areas where Alzheimer II astrocytes usually proliferate. Diffuse 
astrocytic proliferation in the white matter and focal reaction in gray matter, 
which we ascribe to complicating factors, the foremost of which is anoxia, was 
found in many of the cases.