Bidirectional and reciprocal control of astrocyte free calcium by modest fluctuations in external potassium
Bibliographic record
Abstract
Abstract Astrocytes sense and respond to changes in the concentration of extracellular K + , and separately contribute to multiple physiological processes through Ca 2+ dependent mechanisms. Yet, whether a modest change in [K + ] o impacts astrocyte free Ca 2+ remains unclear. Using relative or quantitative two-photon fluorescence Ca 2+ imaging in acute brain slices or in vivo in the somatosensory cortex from Sprague Dawley rats and C57Bl/6 mice, we showed that changes to external K + (+/-1mM to 2.5mM) reciprocally controls the astrocyte Rhod-2 or OGB-1 Ca 2+ -dependent fluorescence in the soma, major processes and endfeet. The astrocyte Ca 2+ decrease when [K + ] o was elevated was sensitive to lowering the external concentration of Ca 2+ , Cl - , and HCO 3 - , but not Na + . Unexpectedly, the phenomenon was blocked by inhibiting K-Cl cotransport. Picrotoxin induced ictal neural activity drove an analogous decrease of astrocyte Ca 2+ . K + mediated cerebral arteriole dilation in brain slices was also sensitive to inhibiting K-Cl cotransport as well as whole-cell patching a peri-arteriole astrocyte which perturbs normal Ca 2+ , Cl - and HCO 3 - concentration gradients. These data reveal subtle, bidirectional regulation of astrocyte free Ca 2 via fluctuations of [K + ] o within the physiological range.
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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 | 0.000 | 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".