Developmental changes in pontine influence on respiratory rhythm generation in neonatal rats: effect of age versus tissue oxygenation
Bibliographic record
Abstract
Pontine ablation depressed respiratory frequency in in vitro rat brainstem spinal cord preparations from postnatal rat pups on the day of birth (P0) but increased burst frequency in 2 and 4 day old (P2, P4) preparations. To examine the extent to which the response to pontine removal and the effects of age on this response represented developmental changes versus changes in tissue mass and oxygenation of the preparation, we first examined the effect of chemical rather than physical lesion of the pons with tetrodotoxin (0.5μM) in a split bath preparation to inactivate the pons without reducing tissue mass. We found chemical lesions had a similar effect as physical ablation. Next, using an O 2 sensing microelectrode, we found that pontine ablation did not affect PO 2 in the medulla at the level of the PreBötzinger Complex. PO 2 reached zero around 1mm from the ventral surface in the absence and presence of the pons, suggesting adequate oxygenation of the ventral respiratory group. These data confirm that the role of the pons and the changes seen in pontine influence on respiratory rhythm over early development are not an artifact of changes in tissue mass or oxygenation. Supported by the NSERC of Canada.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".