Table 1.
Metabolite responses to chromatic and achromatic stimulations quantified from the fMRS data.
| Baseline data |
Δconc. STIM-REST |
|||||
|---|---|---|---|---|---|---|
| conc. | CRLB | CHROM |
ACHROM |
|||
| mean ± SEM | mean | mean | mean ± SEM | mean | mean ± SEM | |
| (µmol/g) | (%) | (%) | (µmol/g) | (%) | (µmol/g) | |
| Asc | 0.98 ± 0.04 | 14.5 | −2.2 | −0.04 ± 0.03 | −4.8 | −0.04 ± 0.03 |
| Asp | 3.35 ± 0.12 | 7.5 | −5.1 | −0.18 ± 0.03* | −5.3 | −0.19 ± 0.04* |
| GPC | 0.59 ± 0.02 | 8.8 | 1.6 | 0.01 ± 0.01 | 3.5 | 0.02 ± 0.01 |
| PC | 0.33 ± 0.01 | 15.1 | 1.4 | 0.00 ± 0.01 | −0.9 | −0.01 ± 0.01 |
| Cr | 4.18 ± 0.06 | 3.2 | 0.6 | 0.02 ± 0.02 | 1.4 | 0.05 ± 0.03 |
| PCr | 3.42 ± 0.07 | 4.1 | 0.8 | 0.03 ± 0.02 | 0.8 | 0.03 ± 0.02 |
| GABA | 1.12 ± 0.07 | 16.0 | −1.6 | −0.03 ± 0.03 | 5.5 | 0.03 ± 0.06 |
| Glc | 0.80 ± 0.14 | 21.0 | −10.0 | −0.10 ± 0.03 | −22.3 | −0.19 ± 0.04* |
| Gln | 2.45 ± 0.12 | 5.8 | 0.1 | 0.00 ± 0.02 | 2.3 | 0.05 ± 0.02 |
| Glu | 8.53 ± 0.17 | 2.0 | 3.1 | 0.25 ± 0.03** | 3.9 | 0.32 ± 0.05** |
| GSH | 1.13 ± 0.02 | 6.3 | 0.7 | 0.01 ± 0.01 | 0.2 | 0.00 ± 0.02 |
| myo-Ins | 5.89 ± 0.17 | 2.0 | 0.4 | 0.02 ± 0.02 | 0.6 | 0.04 ± 0.02 |
| Lac | 0.93 ± 0.06 | 9.4 | 29.0 | 0.23 ± 0.03** | 28.5 | 0.19 ± 0.06** |
| NAA | 12.10 ± 0.20 | 1.0 | 0.1 | 0.02 ± 0.03 | −0.1 | −0.01 ± 0.03 |
| NAAG | 1.27 ± 0.04 | 6.1 | −0.6 | −0.01 ± 0.01 | −1.0 | −0.01 ± 0.01 |
| PE | 0.88 ± 0.02 | 9.3 | 0.2 | 0.00 ± 0.02 | 1.0 | 0.01 ± 0.02 |
| scyllo-Ins | 0.36 ± 0.07 | 10.8 | 4.1 | 0.01 ± 0.01 | 0.8 | 0.00 ± 0.00 |
| Tau | 1.24 ± 0.05 | 10.4 | 3.4 | 0.04 ± 0.02 | 3.5 | 0.03 ± 0.03 |
| Quantification of difference
spectrum |
||||||
| CHROM |
ACHROM | |||||
| CRLB | conc.±CRLB | CRLB | conc.±CRLB | |||
| (%) |
(µmol/g) | (%) | (µmol/g) | |||
| Asp | 19 | 0.15 ± 0.04 | 18 | 0.18 ± 0.04 | ||
| Glc | 19 | 0.08 ± 0.02 | 14 | 0.14 ± 0.02 | ||
| Glu | 8 | 0.22 ± 0.02 | 8 | 0.23 ± 0.02 | ||
| Lac | 6 | 0.25 ± 0.02 | 7 | 0.23 ± 0.02 | ||
Note: The upper panel of the table reports average steady-state metabolite concentrations under the baseline REST condition and their changes (STIM-REST) and percent changes ((STIM-REST)/REST) induced by chromatic (CHROM) and achromatic (ACHROM) stimulations averaged across 12 subjects and 2 sessions. Statistics: t-test followed by the FDR analysis for multiple testing (18 metabolites, probability of false discovery = 5%), levels of significance: **p < 0.0006, *p < 0.006. The lower panel of the table reports metabolite responses quantified from the difference spectra (Figure 5). The Cramér-Rao Lower Bounds (CRLB) provided by LCModel were used as estimates for quantification errors.