Effects of Propofol on Hippocampal Synaptic Transmission in Behaving Rats
Bibliographic record
Abstract
BACKGROUND: The action of propofol has been studied in vitro and in vivo, but the effects of intravenously administered propofol on synaptic transmission in freely behaving rats have not been studied before. METHODS: Rats were implanted with recording electrodes in the dentate gyrus and with stimulation electrodes in the medial perforant path (MPP). Paired pulses at different interpulse intervals (IPIs) were delivered to the MPP, and average evoked potentials were recorded in the dentate gyrus before and after a bolus of propofol (10 or 20 mg/kg administered intravenously) or control vehicle was injected via femoral vein cannula. Because of the layered structure of the hippocampus, population excitatory postsynaptic potentials and population spikes could be distinguished and analyzed. RESULTS: Propofol has no significant effect on the population excitatory postsynaptic potentials or population spike evoked by a single MPP stimulus pulse. However, paired-pulse inhibition of the dentate population spikes was increased at IPI of 20 and 30 ms. Paired-pulse inhibition of the population spike was most prominent when tail pinch response was lost (deep and moderate anesthesia), but it persisted during light anesthesia. At 200 ms IPI, paired-pulse facilitation of population spikes was observed during moderate anesthesia in most rats. CONCLUSIONS: In freely behaving rats, intravenous propofol enhanced paired-pulse inhibition at < 50 ms IPI, likely by enhancing gamma-aminobutyric acid A receptor-mediated inhibition. Propofol also increased paired-pulse facilitation at 200 ms IPI through an unknown mechanism, which may contribute to the neuroexcitatory effect of propofol.
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 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 | 0.000 |
| 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) | 0.000 | 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 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".