Role of locus coeruleus neurons in central O <sub>2</sub> chemoreflex during development in <i>Rana catesbeiana</i>
Bibliographic record
Abstract
In bullfrog, brainstem hypoxia elicits stage‐dependent changes in fictive lung ventilation in vitro . Noradrenergic neurons seem necessary to this reflex because α 1 ‐adrenoceptor inactivation prevents this response. Since we know that locus coeruleus (LC) contains a wide concentration of noradrenergic neurons in amphibian, we used an in vitro brainstem preparation from Rana catesbeiana to test the hypothesis that LC neurons are necessary to the fictive lung ventilation response to central hypoxia. We compared the effects of brainstem transection prior nerve VII from pre‐metamorphic tadpoles and adults. Transection before hypoxia prevents the decrease in lung burst frequency in adult frogs and the increase in pre‐metamorphic group from stage XII but not from stages VIII–IX. Immunohistochemistry for tyrosine hydroxylase (TH) showed that in the LC, adults have more TH‐positive neurons than in pre‐metamorphic stages. We conclude that noradrenergic neurons from the LC area are necessary for the manifestation of the central O 2 chemoreflex in Rana . However, these neurons undergo important reorganisation during development. Funded by the Natural Sciences and Engineering Council 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 | 0.000 |
| 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) | 0.001 | 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".