Synaptic Plasticity in Basal Ganglia Output Neurons in Parkinson's Disease Patients
Bibliographic record
Abstract
Parkinson’s disease (PD) is characterized by the loss of dopamine in the basal ganglia and leads to paucity of movements, rigidity of the limbs, and rest tremor. Synaptic plasticity was characterized in the substantia nigra pars reticulata (SNr), a basal ganglia output structure, in 18 PD patients undergoing implantation of deep brain stimulating electrodes. Field evoked potentials (fEPs) in SNr were measured with one microelectrode using single pulses from a second microelectrode ~ 1 mm away. High frequency stimulation (HFS – 4 trains of 2s at 100Hz) in the SNr failed to induce a lasting change in test fEPs amplitudes in patients OFF medication. Following L-Dopa, HFS induced a potentiation of the fEPs that lasted more than 150s. Our findings suggest that extrastriatal dopamine modulates activity dependent synaptic plasticity at basal ganglia output neurons. Dopamine medication state clearly impacts fEP amplitude, and the lasting nature of the increase is reminiscent of LTP-like changes, indicating that aberrant synaptic plasticity may play a role in the pathophysiology of PD.
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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) | 0.000 | 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) | 0.002 | 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".