FIGURE 2.

The percent ¹⁵N labeling in metabolites in cortical slices from Glud1^lox/lox (filled bars) and CNS-Glud1^–/– mice (open bars) mice following incubation in the presence of 1 or 5 mM ¹⁵NH₄Cl for 60 min as detailed in Materials and methods. The percent mono-labeled glutamate (A), aspartate (B), alanine (C), GABA (D) as well as the percent of glutamine being mono- or double labeled (E) was determined from GC-MS analysis of slice extracts as detailed in Materials and methods. Results are averages ± SEM (n = 5–8), and the asterisk indicates a statistically significant difference between Glud1^lox/lox and CNS-Glud1^–/– mice (P < 0.05).