GFAP knockout mice have increased levels of GDNF that protect striatal neurons from metabolic and excitotoxic insults.
Hanbury R, Ling ZD, Wuu J, Kordower JH. GFAP knockout mice have increased levels of GDNF that protect striatal neurons from metabolic and excitotoxic insults. J Comp Neurol. 2003 Jun 30; 461(3):307-16.