The role of the hypothalamus-pituitary-thyroid axis in appetite regulation of goldfish (Carassius auratus)
Bibliographic record
Abstract
This thesis aimed to understand the role that the hypothalamus-pituitary-thyroid (HPT) axis plays in appetite regulation of goldfish (Carassius auratus). I altered nutritional and thyroid statuses to measure the response of thyroid axis components and appetite-regulating peptides. I predicted that fasting would downregulate the thyroid axis and trigger an orexigenic response, while overfeeding would upregulate the thyroid axis and trigger an anorexigenic response. Additionally, I predicted that hyperthyroid conditions would lead to negative feedback of the thyroid axis and an orexigenic response, whilst opposite under hypothyroid conditions. I uncovered for both experiments that the thyroid axis in goldish is most responsive to overfeeding and hyperthyroidism. Overfeeding led to a time-dependent increase in central thyroid transcripts while fasting decreased thyroid hormone degradation peripherally with no central response, no treatment altered levels of thyroid hormone in circulation. Hyperthyroidism resulted in negative feedback to the pituitary, but not hypothalamus, and did not lead to an increase in food intake despite an increase in the levels of thyroxine. The thyroid inhibitor, propylthiouracil, did not induce hypothyroidism or alter the expression of any thyroid axis transcript. Appetite-regulating peptides correlated weakly to changes in the thyroid, suggesting an overall poor association in goldfish between appetite regulation and thyroid status.
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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".