Figure 7.

(a) In vivo MRS spectra for a typical mouse brain over a voxel in the thalamus before (blue) and after (red, 30 min) D-glucose infusion. Difference spectra at three time points (green) are also shown with two glucose peaks (3.4 ppm and 3.7 ppm) are indicated. (b) Dynamic MRS signal changes as a function of time relative to the start of D-glucose infusion (n = 2). The D-glucose to total creatine (tCr) ratios were calculated by integrating signal over the chemical shift range from 3.0 to 4.2 ppm in the difference spectrum and divided by the area of the tCr methyl group centered at 3 ppm. The solid line is the curve fitted with a single exponential function (equation (7)).