Orphanin FQ Cells of the Ovine Hypothalamus Express Estradiol Receptor-Alpha and Progesterone Receptors, but Not Kisspeptin or Tyrosine Hydroxylase.
Bibliographic record
Abstract
Orphanin FQ (OFQ) is an opioid-like peptide that like opioids has inhibitory effects on the reproductive neuroendocrine axis: infusions of OFQ or an agonist into the 3rd ventricle suppress pulsatile luteinizing hormone (LH) secretion in ovariectomized ewes. OFQ is colocalized in >90% of gonadotropin-releasing hormone (GnRH) neurons in the ovine hypothalamus suggesting a potential autocrine role, but is also present in other neurons in the ARC and other hypothalamic regions. In the ARC, OFQ cells overlap the location of cells expressing estrogen receptor-alpha (ERalpha) and progesterone receptors (PR) raising the possibility that OFQ may, in part, mediate the negative feedback influence of estradiol and progesterone to GnRH neurons. To examine this possibility, we carried out studies to examine the coexpression of OFQ with ERalpha or PR. Gonadal-intact ewes (n=3) were perfused intracranially with 2% paraformaldehyde during the mid-luteal phase of the estrous cycle, and brains processed for dual immunoperoxidase detection of OFQ and either ERalpha or PR. We found that in rostral, middle, and caudal levels of ARC between 80-95% of OFQ cells colocalized ERalpha, and 60-80% colocalized PR. In addition, 75% and 60% of OFQ cells in the AHA, and 30% and 44% of OFQ cells in the VMH contained ERalpha and PR, respectively. By contrast, almost no (<2%) OFQ cells in the POA or PVN colocalized ERalpha or PR. The high degree of colocalization of OFQ neurons in the ARC with ERalpha and PR suggested that they might also contain kisspeptin, but sections processed for dual immunofluorescence showed this is not the case. Similarly, OFQ cells of the ARC did not colocalize tyrosine hydroxylase. Thus, OFQ cells of the ARC are a separate and distinct population from either kisspeptin or dopaminergic cells. Overall, the results suggest that the inhibitory influence of OFQ on GnRH/LH secretion may play a role in estradiol or progesterone negative feedback, and that this influence may be conveyed via OFQ cells in the ARC, VMH or AHA. Recent data using an antagonist to the OFQ receptor support a role for OFQ in progesterone negative feedback in ewes (see abstract by Nestor et al at this meeting). Research supported by NIH R01HD39916 to MNL and RLG. (poster)
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| 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".