Microglia imaging in methamphetamine use disorder: a positron emission tomography study with the 18 kDa translocator protein radioligand [F‐18]FEPPA
Bibliographic record
Abstract
Abstract Activation of brain microglial cells, microgliosis, has been linked to methamphetamine (MA)–seeking behavior, suggesting that microglia could be a new therapeutic target for MA use disorder. Animal data show marked brain microglial activation following acute high‐dose MA, but microglial status in human MA users is uncertain, with one positron emission tomography (PET) investigation reporting massively and globally increased translocator protein 18 kDa (TSPO; [C‐11](R)‐PK11195) binding, a biomarker for microgliosis, in MA users. Our aim was to measure binding of a second‐generation TSPO radioligand, [F‐18]FEPPA, in brain of human chronic MA users. Regional total volume of distribution ( V T ) of [F‐18]FEPPA was estimated with a two‐tissue compartment model with arterial plasma input function for 10 regions of interest in 11 actively using MA users and 26 controls. A RM‐ANOVA corrected for TSPO rs6971 polymorphism was employed to test significance. There was no main effect of group on [F‐18]FEPPA V T ( P = .81). No significant correlations between [F‐18]FEPPA V T and MA use duration, weekly dosage, blood MA concentrations, regional brain volumes, and self‐reported craving were observed. Our preliminary findings, consistent with our earlier postmortem data, do not suggest substantial brain microgliosis in MA use disorder but do not rule out microglia as a therapeutic target in MA addiction. Absence of increased [F‐18]FEPPA TSPO binding might be related to insufficient MA dose or blunting of microglial response following repeated MA exposure, as suggested by some animal data.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| 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".