GABA X<sub>2</sub> multiplet measured pre‐ and post‐administration of vigabatrin in human brain
Bibliographic record
Abstract
This work demonstrates, in solution and in human brain at 3 tesla, that the X(2)-multiplet of the A(2)M(2)X(2) proton spin system of GABA at 2.315 ppm can be readily resolved from that of the overlapping background, particularly the glutamate multiplet, i.e., the PQ multiplet of the glutamate AMNPQ spin system. Prior to experiment, the values of the stimulated echo acquisition mode (STEAM) sequence parameters TE and TM that maximized the GABA-X(2) discrimination from its background (i.e., 168 ms and 28 ms, respectively) were determined numerically. The determination was made by calculating the spectral response of all contributing metabolites to the STEAM sequence throughout TE/TM space. A baseline GABA concentration (mean +/- standard deviation (SD) of the mean) of 0.78 +/- 0.04 mM was estimated from spectra acquired from a 3 x 3 x 3 cm(3) volume in the parieto-occipital cortex of eight normal control subjects. Five of the eight control subjects were also studied 24 hr post-administration of a single dose of 50 mg.kg(-1) vigabatrin. Four of the five showed increases in GABA in the range of 15-120% of their baseline level.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".