Table 1.

Percent ¹³C labeling of brain amino acids from [2-¹³C]acetate in AβPP-PS1 and wild-type (WT) mice.

Brain region	Infusion time (min)	Groups	Amino acids					CMRAc(ox) (µmol/g/min)	Vcyc/VTCA(N)
			GluC4	GABAC2	GlnC4	AspC3	GluC3		Glu’ergic	GABAergic
Cortex	15	WT	3.8 ± 0.2	3.2 ± 0.7	10.4 ± 0.8	2.3 ± 0.2	0.9 ± 0.2	0.051 ± 0.005	–	–
		AβPP-PS1	3.9 ± 0.1	3.4 ± 0.9	11.9 ± 1.4	2.4 ± 0.5	0.9 ± 0.2	0.064 ± 0.007*	–	–
	90	WT	8.3 ± 0.8	7.4 ± 1.0	17.0 ± 1.2	6.9 ± 0.6	7.6 ± 2.4	–	0.43 ± 0.14	0.51 ± 0.14
		AβPP-PS1	9.3 ± 2.2	7.7 ± 1.8	19.0 ± 3.0	7.4 ± 2.8	6.5 ± 3.7	–	0.44 ± 0.06	0.60 ± 0.08
Hippocampus	15	WT	3.9 ± 0.3	2.4 ± 0.4	12.5 ± 1.0	ND	ND	0.051 ± 0.003	–	–
		AβPP-PS1	3.7 ± 0.4	2.2 ± 0.8	13.2 ± 0.5	ND	ND	0.056 ± 0.004*	–	–
	90	WT	7.3 ± 1.6	6.8 ± 1.7	16.3 ± 2.1	ND	ND	–	0.39 ± 0.14	0.50 ± 0.11
		AβPP-PS1	7.6 ± 0.9	6.8 ± 0.7	17.7 ± 0.9	ND	ND	–	0.48 ± 0.13	0.64 ± 0.16
Striatum	15	WT	4.2 ± 0.1	2.2 ± 0.1	12.2 ± 1.3	ND	ND	0.051 ± 0.007	–	–
		AβPP-PS1	3.5 ± 0.7	1.5 ± 0.4	10.7 ± 1.6	ND	ND	0.051 ± 0.003	–	–
	90	WT	7.5 ± 1.7	6.2 ± 1.6	15.5 ± 3.2	ND	ND	–	0.38 ± 0.04	0.46 ± 0.12
		AβPP-PS1	8.7 ± 2.0	7.3 ± 2.1	18.6 ± 3.3	ND	ND	–	0.44 ± 0.06	0.49 ± 0.08

ND: not determined.

Mice were administered [2-¹³C]acetate for 15 and 90 min. The ¹³C labeling of amino acids was measured in brain tissue extracts using ¹H-[¹³C]-NMR spectroscopy. CMR_Ac(ox) and V_cyc/V_TCA(N) were calculated using equations (1) to (3). Values represent mean ± SEM. *p< 0.05 when compared with respective controls.