Increased adenosine A2A receptors in the brain of Parkinson's disease patients with dyskinesias
Bibliographic record
Abstract
Brain adenosine A2A receptors have recently attracted considerable attention because of their interaction with the dopaminergic system and as potential targets for Parkinson's disease pharmacotherapy. Post mortem adenosine A2A receptor mRNA and [3H]SCH 58261- specific binding to adenosine A2A receptor were studied in the brain of Parkinson's disease patients using in situ hybridization and receptor binding autoradiography, respectively. Fourteen levodopa-treated Parkinson's disease patients, of which seven developed dyskinesias and seven did not, were compared with nine controls. Nigrostriatal denervation was similar between dyskinetic and non-dyskinetic Parkinson's disease patients, as assessed with catecholamine concentrations and [125I]RTI-121-specific binding to dopamine transporters. A2A receptor mRNA levels (+129%; P < 0.01) and [3H]SCH 58261-specific binding (+32%, P < 0.01) were increased in the putamen (lateral and medial) of dyskinetic patients compared with controls. The increase of adenosine A2A receptor mRNA in dyskinetic Parkinson's disease patients was also significant compared with non-dyskinetic Parkinson's disease patients (+60%; P < 0.05) in the lateral putamen. Moreover, [3H]SCH 58261-specific binding to adenosine A2A receptors was increased in the external globus pallidus (+24%; P < 0.001) of Parkinson's disease patients compared with controls, regardless of the dyskinesigenic response to levodopa. No change of adenosine A2A receptors was observed in the caudate nucleus, whereas adenosine A2A receptor protein and mRNA levels in the internal globus pallidus were not different from background. These findings suggest that increased synthesis of adenosine A2A receptors in striatopallidal pathway neurons is associated with the development of dyskinesias following long-term levodopa therapy in Parkinson's disease.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".