GABAergic modulation of descending inhibitory systems from the rostral ventromedial medulla (RVM). Dose-response analysis of nociception and neurological deficits
Bibliographic record
Abstract
We have examined the effects of muscimol and bicuculline microinjected in the rostral ventromedial medulla (RVM) on motor function and on nociception in three pain tests. In Exp. 1 microinjection of muscimol (6.25-400 ng in 1 microl) in the RVM dose-dependently decreased pain threshold of rats and the ED(50) for muscimol was the same in both the hot plate and tail immersion pain tests. In the hot plate test, but not in the tail immersion test, paw withdrawal latencies increased again with high doses of muscimol (75-400 ng). High doses also produced catalepsy. Exp. 2 examined the effects of muscimol (50 ng) and bicuculline (50 ng) over a range of formalin concentrations (0.25-4%) in the formalin test. Muscimol increased responsiveness to formalin and reduced the slope of the formalin dose-response relation. Bicuculline decreased responses to formalin and reduced the slope of the formalin dose-response relation. It is suggested that RVM cells with inhibitory projections to the dorsal horn are not subject to strong GABAergic influence under mild noxious stimulation. RVM cells are thus active, and spinal dorsal horn relay neurons are inhibited. On the other hand, intense noxious peripheral stimulation may stimulate the release of GABA onto RVM cells, which in turn shuts off descending inhibitory fibers to allow transmission of nociceptor input through the dorsal horn.
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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 | 0.002 | 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".