Hormone Phase Considerations On Corticospinal Pathway Measures In Males And Females
Bibliographic record
Abstract
Previous evidence suggests that hormones may impact excitatory and inhibitory neurophysiological outcomes differently in males and females. However, sex- and hormone-related differences in excitability and inhibition of the corticomotor pathway have not been widely studied. PURPOSE: To examine sex-related differences and hormone phase influences on corticospinal excitability and inhibition. METHODS: Thirty participants, 15 males (23.3 ± 1.3 yrs), 15 females (22.9 ± 2.8 yrs), visited the laboratory for 2 visits, one in each of their high and low hormones phases. Males were tested in the morning and in the afternoon, while females were tested in the mid-follicular and in the mid-luteal phase of their menstrual cycle. Electromyography was recorded from the first dorsal interosseous muscle in response to transcranial magnetic stimulation. Single-pulse and paired-pulse stimuli were used to assess excitability via the motor-evoked potential (MEP) and intracortical facilitation (ICF) and inhibition via the cortical silent period (CSP), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI). All outcome measures were compared between phases within each sex and between males and females with averaged phase data. RESULTS: No significant differences in excitability were found between sexes (MEP: p = 0.09, d = 0.65; ICF: p = 0.65, d = 0.17), nor between phases for males (MEP: p = 0.67, d = 0.12; ICF: p = 0.24, d = 0.32) or females (MEP: p = 0.25, d = 0.31; ICF: p = 0.95, d = 0.02). Males displayed greater inhibition compared to females in SICI (p = 0.004, d = -1.15) and LICI (p = 0.008, d = -1.12) but not CSP (p = 0.28, d = 0.40). Within males, inhibition did not differ across phases (CSP: p = 0.13, d = 0.41; SICI: p = 0.33, d = 0.26; LICI: p = 0.70, d = 0.11). In females CSP (p = 0.04, d = 0.60) indicated greater inhibition in the low hormone phase, however there was no significant difference between phases for the other measures of inhibition (SICI: p = 0.80, d = 0.07; LICI: p = 0.63, d = 0.13). CONCLUSION: These results suggest hormone phase may be an important consideration for CSP, but not for other measures of corticospinal inhibition or for measures of excitability. Supported by: Natural Sciences and Engineering Research Council of Canada (NSERC) RGPIN-2019-05127
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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 | 0.001 | 0.002 |
| 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) | 0.004 | 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".