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Isovaline, a rare amino acid, has anticonvulsant properties in two in vitro hippocampal seizure models by increasing interneuronal activity

2011· article· en· W1537540865 on OpenAlexafffund
Damian S. Shin, Wilson Yu, Alex Sutton, Megan Calos, E. Puil, Peter L. Carlen

Bibliographic record

VenueEpilepsia · 2011
Typearticle
Languageen
FieldMedicine
TopicSpaceflight effects on biology
Canadian institutionsToronto Western HospitalUniversity of TorontoUniversity Health NetworkUniversity of British Columbia
FundersCanadian Institutes of Health Research
KeywordsHippocampal formationChemistryAnticonvulsantNeuroscienceIn vitroElectrophysiologyExtracellularPharmacologyBiophysicsEpilepsyMedicineBiologyBiochemistry

Abstract

fetched live from OpenAlex

PURPOSE: We investigated whether RS-isovaline, a unique amino acid found in carbonaceous meteorites and presumed extraterrestrial, has anticonvulsant properties in rat hippocampal slices in vitro. METHODS: Extracellular recordings were obtained in the rat hippocampal CA1 pyramidal layer in two in vitro seizure models: perfusion of low (0.25 mm) Mg(2+) and high (5 mm) K(+) (LM/HK), or 100 μm 4-aminopyridine (4-AP). To investigate the underlying mechanisms of isovaline action, whole-cell recordings were obtained from CA1 pyramidal neurons and stratum oriens interneurons during 4-AP blockade of K(+) channels. KEY FINDINGS: Perfusion of LM/HK produced seizure-like events (SLEs) or stimulus-evoked primary afterdischarges (PADs) with amplitudes of 0.9 ± 0.1 mV lasting 80 ± 14 s. Application of isovaline (250 μm) for 20-30 min abolished SLEs and PADs or attenuated seizure amplitude and duration by 57.0 ± 9.0% and 57.0 ± 12.0%, respectively. Similar effects were seen with isovaline in the 4-AP seizure model. Isovaline alone increased interneuronal spontaneous spiking from 0.9 ± 0.3 to 3.2 ± 0.9 Hz, increased input resistance by 21.6 ± 8.1%, and depolarized the resting membrane potential by 8.0 ± 1.5 mV; no changes in the firing or electrical properties of pyramidal neurons were observed. Coapplication of 4-AP and isovaline increased interneuronal spontaneous spiking from 1.0 ± 0.6 to 2.6 ± 0.8 Hz, whereas pyramidal neuronal spiking activity decreased from 0.6 ± 0.4 to 0.2 ± 0.1 Hz. SIGNIFICANCE: Isovaline exhibited anticonvulsant properties in two hippocampal seizure models. This may lead to the development of a new class of anticonvulsants based on an unusual mechanism of action of this presumed extraterrestrial amino acid.

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 imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.136
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.066
GPT teacher head0.281
Teacher spread0.214 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

Study designBench or experimental
Domainnot available
GenreEmpirical

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".

Quick stats

Citations15
Published2011
Admission routes2
Has abstractyes

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