Synaptic impairment induced by paroxysmal ionic conditions in neocortex
Bibliographic record
Abstract
PURPOSE: Seizures are associated with a reduction in extracellular Ca²(+) concentration ([Ca²(+) ](o) ) and an increase in extracellular K(+) concentration ([K(+) ](o) ). The long-range synchrony observed between distant electrodes during seizures is weak. We hypothesized that changes in extracellular ionic conditions during seizures are sufficient to alter synaptic neuronal responses and synchrony in the neocortex. METHODS: We obtained in vivo and in vitro electrophysiologic recordings combined with microstimulation from cat/rat neocortical neurons during seizures and seizure-like ionic conditions. In vitro the [K(+) ](o) was 2.8, 6.25, 8.0, and 12 mm and the [Ca²(+) ](o) was 1.2 and 0.6 mm. KEY FINDINGS: During seizures recorded in vivo, we observed abolition of evoked synaptic responses. In vitro, the membrane potential of both regular-spiking and fast-spiking neurons was depolarized in high [K(+) ](o) conditions and hyperpolarized in high [Ca²(+) ](o) conditions. During high [K(+) ](o) conditions, changes in [Ca²(+) ](o) did not affect membrane potential. The synaptic responsiveness of both regular-spiking and fast-spiking neurons was reduced during seizure-like ionic conditions. A reduction in [Ca²(+) ](o) to 0.6 mm increased failure rates but did not abolish responses. However, an increase in [K(+) ](o) to 12 mm abolished postsynaptic responses, which depended on a blockade in axonal spike propagation. SIGNIFICANCE: We conclude that concomitant changes in [K(+) ](o) and [Ca²(+) ](o) observed during seizures contribute largely to the alterations of synaptic neuronal responses and to the decrease in long-range synchrony during neocortical seizures.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".