Morphometric analysis of the blood‐brain barrier in the peri‐infarct zone in young adult and aged mice
Bibliographic record
Abstract
After an ischemic stroke, the blood brain barrier (BBB) is compromised in the peri‐infarct zone leading to secondary injury and neuronal dysfunction that can limit brain recovery. There is uncertainty what accounts for an increase in BBB permeability in capillaries of peri‐infarct tissues, particularly in aged animals. We utilized electron microscopy to study early (3 h) and late (72 h) changes to the BBB in young (3–4 mo) adult and aged (18 mo) mice after photothrombotic stroke. In all groups, peri‐infarct BBB permeability (as determined by Evans blue extravasation) was accompanied by endothelial swelling and an increase in transcytotic vesicles and vacuoles. In flowing capillaries, tight junctions (TJ) between endothelial cells were intact although small gaps were detected in a fraction of cases. In young adult mice (but not old mice) there was a marked increase in pericyte size and coverage of the capillaries. In both groups, thickening of the underlying basement membrane of capillaries peaked at 3 h and partially recovered by 72 h in young but not aged mice. Surrounding astrocytes and their mitochondria were severely swollen at both times points and ages. At 72 h, astrocytes were filled with glycogen deposits suggesting an upregulation of energy storage. These data suggest that BBB permeability in the peri‐infarct cortex of young adult and aged animals is likely mediated by transcellular pathways rather than TJ disruption. Additionally, our results indicate that pericyte and basement membrane responses to ischemia are affected by aging. Support or Funding Information Heart and Stroke Foundation of BC and Yukon, CIHR, MSFHR, CFI, NSERC
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 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".