Metamorphosis of a clock: Remodeling of the circadian timing system in the brain of <i>Rhodnius prolixus</i> (Hemiptera) during larval‐adult development
Bibliographic record
Abstract
The rhythmic phenomena expressed by organisms change over their lifetimes, but little is known of accompanying reorganization of the central circadian timing system in the brain. Especially dramatic changes in overt rhythms and morphology occur during transformation of larval insects into the adult form (metamorphosis). In Rhodnius prolixus, both the physiology of metamorphosis and its hormonal control are known in detail. Here we report changes in the brain timing system as revealed by pigment dispersing factor immunohistochemistry and confocal microscopy. Most of the features of the larval system are retained, but new clock cells differentiate and the arborizations of their axons increase in complexity, as do pathways connecting the lateral (LNs) and dorsal (DNs) groups of clock neurons. Early in metamorphosis, the LNs increase from 8 to 11 in number, becoming five small and six large LNs. Two large LNs then migrate to new positions in the protocerebrum. Another clock cell differentiates in the posterior protocerebrum. Each change occurs at a characteristic concentration of the ecdysteroid molting hormones that regulate metamorphosis. Clock cell axons invade the mushroom body and corpus allatum and travel down the ventral nerve cord. New overt rhythms develop during metamorphosis, in which these structures participate. The neuroendocrine cells of the brain receive more extensive branches of clock cell axons than in larvae. These increases in size and complexity of the circadian system during metamorphosis imply a greater complexity and diversity of outputs from it to both behavioral and hormonal rhythms in the adult.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".