Endocrine Effects of Brain Serotonin Depletion by 5,6-Dihydroxytryptamine in Prepuberal Male Rats
Bibliographic record
Abstract
The effects of selective degeneration of brainserotoninergic nerve terminals by 5,6-dihydroxytryptamine (5,6-DHT) injected intraventricularly in prepuberal male rats were studied in 2 experiments. In both experiments, male Sprague-Dawley rats were injected in a lateral ventricle of the brain at 21 and 23 days of age with either 5,6-DHT or vehicle, and autopsied 1,2 and 4 weeks after the 1st injection. Controls were either pair-fed or fed ad lib. In the first experiment the effects of 5,6-DHT on body and organ growth and pituitary levels of radioimmunoassayable growth hormone (GH) were studied. In the second experiment the effects of 5,6-DHT on plasma and pituitary levels of radioimmunoassayable follicle-stimulating hormone (FSH) were studied. Histological examinations of the testes obtained at 4 weeks were performed. Experimental animals on the whole ate 41.8 % less food than controls fed ad lib. The analysis of variance showed that experimental animals, when compared with pair-fed controls, had significantly lower brain 5-HT levels (as measured by spectrophotofluoro-metry) at 1 and 2 weeks, significantly lower body weights at 1 week, and significantly smaller tails at 1 and 2 weeks after the first injection. Brain weights of experimental rats were significantly lower than those of controls fed ad lib. at 2 and 4 weeks; those of pair-fed animals, although lower at 2 weeks, were not significantly different from brain weights of controls fed ad lib. at 4 weeks. At 4 weeks, testes weights (corrected for body weights) were significantly lower in experimental rats than in controls fed ad lib. At 2 weeks, both the experimental and the pair-fed group had pituitary GH levels (corrected for body weights) lower than those of the group fed ad lib. Plasma FSH levels were undetectable at 1 week both in experimental and pair-fed animals. Pituitary FSH concentration was significantly reduced at 2 weeks and significantly increased at 4 weeks in the experimental rats when compared with the controls fed ad lib. Histological examination of the testes showed that controls fed ad lib. and pair-fed had reached full spermatogenesis at 4 weeks after the 1st injection (51 days of age); spermatogenesis of experimental animals was usually blocked at the stage of pachytene spermatocytes. In conclusion, depletion of brain 5-HT inhibited body and brain growth and sexual maturation partly through the ensuing anorexia and malnutrition, but possibly also through a specific decrease in synthesis and/or secretion of GH and FSH.
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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 | 0.000 | 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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".