Expression levels of enzymes associated with the glutamate-glutamine cycle. (A) Scatter plots of enzyme optical density values for control subjects (n = 13) and individuals with autism (n = 7). Results are expressed as a percent of the control values, normalized by the β-actin level. (B) Western blots showing immunolabeling of KGA, LGA, GS, GDH1, GDH2, GFAP, NSE, and β-actin in the anterior cingulate cortex (ACC) of control subjects (n = 13) and individuals with autism (n = 7). Abbreviations: GDH1, glutamate dehydrogenase 1; GDH2, glutamate dehydrogenase 2; GFAP, glial fibrillary acidic protein; GS, glutamine synthetase; KGA, kidney-type glutaminase; LGA, liver-type glutaminase; NSE, neuron-specific enolase.