Orthostatic Response in Rats After Hindlimb Unloading: Effect of Transcranial Electrical Stimulation
Bibliographic record
Abstract
INTRODUCTION: Orthostatic hypotension is a commonly observed phenomenon after exposure to microgravity and in various forms of autonomic failure. It has been suggested that insufficient activation of supraspinal structures responsible for descending sympathetic drive could play a significant role in this disorder. We examined the effect of transcranial electrical stimulation (TES) of autonomic nuclei within the brain on the orthostatic hypotension induced by exposure to simulated microgravity using a hindlimb unloading model. METHODS: There were 20 male Wistar rats that were suspended by their tail with the angle of elevation between the cage floor and the rat's body approximately 40 degrees. There were 11 age-matched Wistar rats used as cage controls. Orthostatic stability was examined by using an orthostatic challenge test (450 head-up test for a period of 3 min). In 10 rats from the tail-suspended group, the orthostatic challenge test was applied during TES. RESULTS: In the rats exposed to simulated microgravity (tail suspension), the orthostatic challenge test caused a significant decrease in mean arterial blood pressure by 18.4 +/- 2.2%. TES attenuated this microgravity-induced orthostatic hypotension to 9.5 +/- 1.8% (P < 0.05), which was similar to the observed response to an orthostatic challenge in the control group (6.9 +/- 1.1%). DISCUSSION: Results of this study suggest that TES significantly reduces the changes in blood pressure during an orthostatic challenge test in animals exposed to simulated microgravity. Our observations support the notion that a reduction in descending sympathoexcitatory input from supraspinal structures could contribute to orthostatic hypotension and intolerance observed in astronauts following their return from spaceflight.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 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) | 0.002 | 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".