β‐Adrenergic blockade in the dentate gyrus in vivo prevents high frequency‐induced long‐term potentiation of EPSP slope, but not long‐term potentiation of population spike amplitude
Bibliographic record
Abstract
High frequency (HF)-induced and norepinephrine (NE)-induced long-term potentiation have been hypothesized to utilize common mechanisms of induction and expression in the dentate gyrus. In vitro data tend to support this hypothesis, but few studies have been done in vivo. The present study records perforant path-evoked potentials simultaneously on two micropipettes, one filled with saline and the other with the beta-antagonist, timolol. Stimulation of the paragigantocellularis nucleus (PGi) was used as a method of producing NE release in the dentate gyrus, and thus, to assess the efficacy of beta-receptor blockade on the timolol pipette. Beta-blockade by timolol attenuated PGi-induced spike potentiation. HF-induced potentiation of the excitatory post-synaptic potential (EPSP) slope was also blocked by timolol, but HF-induced spike amplitude potentiation was unaffected. These results are consistent with an earlier report examining HF-long-term potentiation (LTP) following 6-OHDA-induced NE depletion, which showed that the EPSP slope LTP depended, for its full expression, on NE, but potentiation of the population spike amplitude component of HF-induced LTP did not. In the present study, PGi-induced potentiation of spike amplitude on the saline pipette was normal after HF-induced saturation of spike amplitude potentiation, suggesting that the mechanisms for expression of spike potentiation, as well as induction of spike potentiation, are separate for HF and NE stimulation.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 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".