Ultrasound measurements of fetal breathing movements in the rat
Bibliographic record
Abstract
The goal of this study was to determine when fetal breathing movements (FBMs) commence in the rat and to characterize age-dependent changes of FBMs in utero. These data provide a frame of reference for parallel in vitro studies of the cellular, synaptic, and network properties of the perinatal rat respiratory system. Ultrasound recordings were made from unanesthetized Sprague-Dawley rats from embryonic (E) day 15 (E15) to E20. Furthermore, the effects of respiratory stimulants (doxapram and aminophylline) and hypoxia on FBMs were studied. Single FBMs, occurring at a very low frequency (approximately 8 FBMs/h), commenced at E16. The incidence of single FBMs increased to approximately 80 FBMs/h by E20. Episodes of clustered rhythmic FBMs were first observed at E18 (approximately 40 FBMs/h). The incidence of episodic clustered FBMs increased to approximately 300 FMBs/h by E20, with the duration of each episode ranging from approximately 40 to 180 s. Doxapram, presumably acting to stimulate carotid body receptors, did not increase FBMs until E20, when the incidence of episodic clustered FBMs increased twofold. Aminophylline, a central-acting stimulant, caused an increase in episodic clustered FBMs after E17, reaching significance at E20 (3-fold increase). Exposing the dam to 10% O(2) caused a rapid, marked suppression of FBMs (5-fold decrease) that was readily reversed on exposure to room air.
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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 | 0.001 | 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".