In plain terms

The claim being assessed: Excitotoxicity—excess glutamatergic signaling from impaired astrocytic EAAT2/GLT-1 clearance and calcium-permeable AMPA receptors—is the causal driver of motor-neuron death in ALS.

Where the evidence stands: Γ — Plausible mechanism. There is a believable biological story and partial support, but the causal step has not been demonstrated.

What this mechanism does: This makes the process worse or keeps it going, but something else starts it.

Strongest evidence for it: Preregistered scope-matched SC4 returns Γ. SC2 Ζ is a bounded forced-lesion result, and SC3 Ε is a SOD1 progression result. Weakest-link sensitivity is Β from descriptive SC1, so that aggregation would mix association depth with a distinct causal-driver question.

What decisive evidence would look like

In plain terms, researchers would change the proposed cause, confirm it changed as intended, and measure a meaningful health outcome while checking other explanations. The result should be able to support or count against the claim.

Relative explanatory fit: Alternative ranked ahead

What this review means

ALS damages the nerve cells that control muscles. This review asks whether excessive glutamate signaling drives that loss, separating engineered lesions, disease models and evidence from patients.

Implications for health and treatment: Preregistered scope-matched SC4 returns Γ. SC2 Ζ is a bounded forced-lesion result, and SC3 Ε is a SOD1 progression result. Weakest-link sensitivity is Β from descriptive SC1, so that aggregation would mix association depth with a distinct causal-driver question.

Limits for individual care: 69 primary reports with 6 selected partial-body examinations; density, heterogeneous controls and incomplete access set the confidence, not correctness. The grade applies to the exact registered claim; stronger findings for narrower subclaims remain separate. No complete-paper audit or blinded calibration is claimed. This educational review does not establish an individual treatment recommendation.

Medical information notice: This review provides general health information, not medical advice. It cannot diagnose a condition or replace an individual discussion with a qualified clinician.

Source checking used complete abstracts/status records and selected original partial-body passages. No complete-paper audit or independent scientific peer review is claimed. Detailed access counts and limitations appear in the review.

A low grade is not an accusation. It means the causal work has not been done yet, which is the ordinary state of most actively studied mechanisms in biology.

At a glance

Sub-claims assessed separately

Figures

Explanatory figures summarizing this review. They carry no evidential weight of their own; where a figure and the review differ, the review governs.

Full assessment

From here the review is written for a technical reader: caps and thresholds, competing models, the independence basis, and the citation ledger.

Sources: 69 primary reports; claims: 75; verified: 75; unverified: 0. Verification is bounded attribution. Access: 6 partial-body and 63 complete abstract/status examinations. Literature cutoff: 2026-10-08; source examination UTC date: 2026-10-08. No complete-paper audit or blinded calibration claimed.

Adversarial review: Generated by Sol 6.1; adversarially reviewed by Claude Opus 5.5 (Anthropic) on 2026-10-14. 4 corrections applied (see ADVERSARIAL REVIEW AND APPROVAL). Status: Approved as revised.

AT A GLANCE

Excitotoxicity is causally damaging in defined motor-neuron models and can modify SOD1 progression; its primacy across sporadic human ALS is not established.

Deciding experiment: Prospectively stratify sporadic ALS by prespecified stage and cell-specific editing/clearance status, then compare selective CP-AMPA or EAAT2 correction with a mechanistically orthogonal RNA/axonal intervention in matched human-derived systems and an adult-onset disease model before a target-engaged clinical trajectory trial.

Belief versus evidence: Preregistered scope-matched SC4 returns Γ. SC2 Ζ is a bounded forced-lesion result, and SC3 Ε is a SOD1 progression result. Weakest-link sensitivity is Β from descriptive SC1, so that aggregation would mix association depth with a distinct causal-driver question.

Best-supported rival: TDP-43/RBP proteostasis failure. A stage-matched comparison of selective receptor/clearance correction versus RNA/axonal correction, with mediator engagement and neuron/axon/function endpoints, separates an obligate glutamate pathway from parallel amplification.

COMPETING MECHANISTIC MODELS

Rank 1: TDP-43/RBP proteostasis failure (Ε). RNA processing and axonal-support defects can precede or recruit excitotoxic stress. Functional UNC13A/STMN2 genetic links and rescue: PMID35197626,35197628,36927019. Does not establish one universal primacy route; excitotoxic edited-GluA2 rescue remains strong in AR2.

Rank 2: Excitotoxicity (Γ). Excess glutamate/calcium stress amplifies motor-neuron injury. ADAR2 edited-receptor rescue and EAAT2 cleavage-resistant SOD1 progression benefit: PMID20826656,28342750. Human clinical specificity is lacking; excitation can protect some presymptomatic motor pools: PMID24094105,32484501.

Rank 3: Distal axonopathy/dying-back (Ε). Axonal support/destruction can drive distal loss before cell bodies fail. Temporal NMJ loss, Stmn2 lesion/rescue and Sarm1 attenuation: PMID14736504,35294901,31661035. Axonal chronology alone cannot exclude a glutamate upstream trigger; behavior does not invariably improve.

Rank 4: Astroglial toxicity beyond glutamate (Ε). Inflammatory and metabolic glial changes interact with neurons. RIPK1 perturbation, TNF-conditioned-medium blockade and MCT1 loss: PMID40132594,29380416,22801498. Different systems and broader perturbations do not prove a common primary glial insult.

Rank 5: Homeostatic excitability compensation (Ε). Excitation can recruit protective signaling in vulnerable motor neurons. Opposite-direction SOD1 activity/mTOR and synaptic rescue: PMID24094105,32484501. Circuit, stage and genotype boundaries preclude treating all hyperexcitability as protective.

The tournament does not alter the nominal level. Compatible pathways and flexible alternatives are not automatically proved by explaining observations.

FULL REVIEW

Registered claim and scope

Excitotoxicity—excess glutamatergic signaling from impaired astrocytic EAAT2/GLT-1 clearance and calcium-permeable AMPA receptors—is the causal driver of motor-neuron death in ALS.

Use index ALS progression scope rather than merge acute stroke and chronic neurodegeneration. Separate forced ADAR2/GLT-1 lesions, SOD1-specific rescue, broad sporadic primacy and generalization. SC4 gates the nominal causal-driver inference; stronger bounded results are visible separately.

Selection: public-interest rank 31 from the editorial ranking compiled 2026-09-23; categorical prior verdicts were visible. Private fresh review; earlier documents are preserved.

Evidence and causal interpretation

ALS tissue and physiological observations support altered glutamate handling or excitability in selected compartments, but their ordering is unresolved. GLT1 loss in matched postmortem tissue admits both primary and secondary interpretations (PMID7611729,8619555); reduced editing/TDP-43 colocalization cannot determine which fails first (PMID20372915). Peripheral platelet and splice-transcript negatives test particular proposed markers, not all excitotoxic mechanisms (PMID16426705,11357955).

The most specific sufficiency/rescue evidence is endogenous ADAR2 deletion plus edited endogenous GluR2 replacement. The original Methods/Results confirm littermate controls, blinded neuronal counting, slow loss of deficient neurons and six-month neuron/motor preservation despite ADAR2 absence (PMID20826656). This tests a deliberately installed neuronal defect. Spinal GLT1 deletion is a separate endogenous glial lesion with motor-neuron loss (PMID29458024), but its original body was unavailable for control auditing.

In SOD1-G93A mice, caspase-resistant EAAT2 acts as a modest progression modifier. Human plasmid D505N and mouse-locus D504N are homologous labels. Native-locus mutation preserves transport-related properties, with SOD1-copy checks; survival increases about 4–5%, while onset and P150 cervical/lumbar neuronal counts do not significantly change (PMID28342750). Reduced toxic fragment formation could contribute beyond glutamate clearance, preventing a one-pathway attribution.

The ceftriaxone original final dataset has 513 participants, 340 active and 173 placebo; Consensus returned 1027 in its table and 514 in its narrative. Original Results show no significant functional or survival benefit, and Discussion explicitly states that CNS EAAT2 activation could not be determined (PMID25297012). Drug exposure and a clinical null therefore cannot settle target necessity.

Perampanel is a material negative translational result, not simply a future opportunity. Sixty-six were randomized, 65 analyzed; 8-mg completion was 7/21 versus 18/22 placebo. The primary mixed-model functional difference was -8.4 points, Table 2 95% CI -15.0 to -1.8; the abstract gives a different interval. LOCF covariance sensitivity was nonsignificant and serious events were more frequent at the high dose (PMID34191081). Attrition and symptomatic toxicity prevent identifying accelerated neuronal death, but also prevent claiming benefit.

Riluzole trials support survival benefit, with multi-action pharmacology and different adjusted/unadjusted statistics (PMID8302340,8676624). Ezogabine reduces excitability in 65 randomized participants, but only four weeks at full dose and no significant clinical progression change cannot establish long-term efficacy (PMID33226425). Acute excitability normalization is a pharmacodynamic finding, not a validated clinical surrogate.

Opposite-direction excitation and mTOR/synaptic rescue experiments challenge a uniform suppress-excitation prediction (PMID24094105,32484501). Cortical inhibitory-interneuron activation can help a different circuit in SOD1 mice (PMID32203578). These findings permit compartmental and stage-dependent amplification, rather than forcing all excitability into one toxic or protective category.

RNA/axon and glial alternatives have their own bounded causal tests: UNC13A/STMN2 processing, endogenous Stmn2 loss/rescue, Sarm1-mediated degeneration, RIPK1 and MCT1 support (PMID35197626,35197628,36927019,35294901,31661035,40132594,22801498). The 2025 YAP work places protective glial EAAT2 induction downstream of an installed poly-GA insult (PMID40860154). Compatible contributors cannot be ranked as universal primacy merely from report counts.

HYPOTHESIS STATE EVALUATION FRAMEWORK (HSEF v5.3)

Subclaim matrix and aggregation

Preregistered aggregation: scope-matched. Preregistered scope-matched SC4 returns Γ. SC2 Ζ is a bounded forced-lesion result, and SC3 Ε is a SOD1 progression result. Weakest-link sensitivity is Β from descriptive SC1, so that aggregation would mix association depth with a distinct causal-driver question. Sensitivities: weakest-link Β; primary-subclaim Γ; scope-matched Γ.

Decisive-perturbation inventory and causal tally

[1] Astrocytic membralin loss lowers EAAT2 and causes motor phenotypes; restoring EAAT2 or membralin protects in engineered settings. Membralin regulates broader inflammatory pathways; forced deletion and SOD1 rescue do not establish sporadic human primacy.

[2] EAAT2 translational activator improves motor function and survival in a mouse ALS model. PKC/YB1 effects and engineered background constrain attribution; clinical spinal engagement is untested.

[5] Astrocytic YAP loss exacerbates poly-GA-model phenotypes; LDN-212320 restores EAAT2 and partially rescues motor and neuronal readouts. Neonatal AAV-GA100 forces the disease insult; YAP has broad effects and neuronal Wnt induction is a protective response. This is not upstream sporadic primacy.

[13] The ceftriaxone phase-3 dataset contains 513 participants (340 active and 173 placebo); functional decline and survival were not significantly improved. CSF exposure did not establish EAAT2 activation; hepatobiliary toxicity and treatment discontinuation constrain a mechanism-level negative inference. Consensus table 1027 and narrative 514 are not the final analysis denominator.

[14] AAV9-ADAR2 delivery rescues motor-neuron loss, function and TDP-43 distribution in conditional ADAR2-deficient mice. Restoring the gene deliberately deleted in AR2 is a matched model test, not intervention in spontaneous human ALS.

[15] Perampanel protects motor and neuronal readouts in AR2 mice. Shares the ADAR2 lesion lineage with other AR2 reports; model rescue does not establish human tolerability or benefit.

[16] Perampanel randomized 66 patients and analyzed 65; only 7/21 in the 8-mg group completed 48 weeks versus 18/22 placebo. Primary mixed-model ALSFRS-R change was worse at 8 mg. Small sample, attrition and symptomatic adverse effects limit attribution to accelerated neuronal death. Table 2 CI for the -8.4 difference is -15.0 to -1.8; abstract gives a different CI. LOCF covariance sensitivity did not retain significance.

[19] ICV AMPA aptamers improve motor and neuronal readouts in AR2 mice. Same conditional ADAR2 platform; no independent sporadic-human causal replication.

[25] Ventral astrocytes regulate strain-dependent GluR2 and motor-neuron susceptibility; mutant SOD1 disrupts this capacity. Rat strain and mutant-protein context restrict generalization and do not isolate a universal initiating pathway.

[26] Conditional ADAR2 loss in a cholinergic motor-neuron subset causes slow neuronal loss; endogenous edited-GluR2 replacement preserves neurons and motor function despite ADAR2 absence. Developmental Cre and selective lesion define the scope; oculomotor neurons resist reduced editing. Original cell counts were blinded; rescue at six months is not a clinical sporadic-ALS test.

[30] VEGF induces GluR2 and lowers AMPA calcium permeability and vulnerability in cultured neurons; ICV treatment induces ventral-spinal expression. VEGF has broad effects; receptor induction in vivo is not isolated ALS survival causation.

[31] Mutant-SOD1 astrocytes are mGluR5-vulnerable; in vivo mGluR5 blockade slows astrocyte damage and modestly delays disease. Interacting astrocyte degeneration is context specific and does not prove motor-neuron AMPA primacy.

[35] Presymptomatic mutant-SOD1 motor-neuron excitation is reduced; independent chemogenetic signaling/activity manipulation restores synapses and improves pathological readouts. Does not refute cortical hyperexcitability or calcium toxicity in other stages; it contradicts uniform benefit from suppressing motor-neuron excitation.

[37] Chemogenetic cortical parvalbumin-interneuron activation reduces pyramidal hyperexcitability and improves onset, neuronal and survival outcomes in SOD1 mice. Cortical circuit modulation differs from spinal motor-neuron silencing; engineered disease and broad network effects limit human inference.

[39] A 155-patient placebo-controlled riluzole trial found a survival advantage and slower strength deterioration. Riluzole has multiple receptor/channel actions; benefit does not identify EAAT2 or AMPA as the necessary causal mediator.

[42] Talampanel phase II randomized 59 ALS participants; favorable numerical strength/ALSFRS trends did not reach statistical significance. Small trial and sedation/dizziness constrain inference; numerical trends are not demonstrated disease modification.

[43] Single-nucleus spinal profiles identify inflammatory glial states; RIPK1 blockade delays SOD1-mouse symptoms and modulates responses. Independent inflammatory pathway is a rival/convergent contributor; human secreted-marker modulation is not patient survival causation.

[44] Astrocytic Kir4.1 loss reduces peak strength and changes fast-motor-neuron size but is dispensable for survival even in SOD1 background. Distinct potassium-support pathway; illustrates strength/death decoupling rather than refuting astrocytic glutamate clearance.

[45] GLT1-expressing transplanted marrow-derived cells improve mouse motor behavior and survival and shift inflammatory markers. Transplantation and immune-state changes prevent clean attribution to astrocytic transporter correction alone.

[47] TDP-43 loss activates a UNC13A cryptic exon; ALS-risk variants increase mis-splicing and reduce protein. Supports a functional genetic/RNA rival, not proof that all neuronal death is independent of excitotoxicity.

[48] Independent experiments link UNC13A risk variants to TDP-43-dependent cryptic splicing and protein depletion. Related human tissues and TDP-43 platforms may overlap; linked erratum PMID38890465 is recorded but details not examined.

[49] STMN2 cryptic processing is corrected by targeted reagents; axonal regeneration/lysosome trafficking recover in deficient human motor neurons. Functional axon repair and engineered humanized mice are not broad clinical survival proof.

[50] Loss of TDP-43 reduces STMN2 through premature polyadenylation; STMN2 restoration rescues axonal regenerative capacity. Axonal regeneration is a bounded functional endpoint, not death prevention in all ALS.

[51] TDP-43/STMN2 perturbation and stabilization connect transcript loss to neurite and regeneration deficits. Shares disease pathway with other STMN2 reports; restoration is not independent clinical causality.

[52] Endogenous Stmn2 loss causes denervation and motor dysfunction; human STMN2 BAC rescues motor phenotypes. Different axonal-support lesion, not selective neuron death caused by glutamate. Linked erratum PMID36480942 remains an unexamined detail.

[53] Sarm1 deletion attenuates TDP-43-model axon/neuromuscular-junction and neuron loss, but not behavioral deficits. Mixed FTD-like model and sex-related viability affect scope; phenotype classes must not be collapsed.

[57] Mutant-FUS astrocyte conditioned medium kills neurons; TNF neutralization blocks toxicity and receptor composition changes accompany it. Tagged forced FUS and culture constrain inference; inflammatory and AMPA routes can be coupled rather than exclusive.

[58] Motor-neuron-derived extracellular miR-218 lowers astrocytic EAAT2; antisense inhibition mitigates changes in ALS mice. Shows an upstream neuron-to-astrocyte feedback alternative; transporter-marker rescue is not demonstrated survival benefit in the examined abstract.

[59] Disrupting oligodendroglial MCT1 injures axons/neurons, and MCT1 is reduced in ALS materials. Independent metabolic-support route; its presence does not exclude interacting glutamate stress or establish universal primacy.

[60] Mouse endogenous EAAT2-D504N blocks cleavage; progression and lifespan improve modestly in SOD1-G93A mice with matched transgene-copy checks. Human plasmid D505N and mouse D504N name homologous sites. Onset and measured P150 motor-neuron counts did not change; reducing toxic CTE-SUMO1 is not uniquely restoring glutamate clearance.

[61] Hoxb8-Cre spinal GLT1 deletion produces motor deficits and motor-neuron loss. Original abstract supports sufficiency within forced spinal deletion; Methods/Results not retrieved by Consensus or local PMC. Developmental timing and matched rescue details remain unverified.

[64] Ezogabine randomized 65 ALS participants, changes cortical/axonal excitability, and showed no significant ALSFRS-R, vital-capacity or strength effect over the short trial. Only four weeks at full dose; this cannot establish durable efficacy or refute a long-term effect. Active-arm discontinuation and biomarker selection constrain generalization.

[66] SOD1, C9orf72 and FUS iPSC neurons show hyperexcitability; isogenic SOD1 correction removes it and retigabine improves mutant-cell survival. Genetic correction validates genotype dependence, while immature cultures and Kv7 effects do not prove common adult glutamatergic primacy.

[67] Enhancing susceptible motor-neuron excitability/mTOR protects in SOD1 models; reducing it worsens pathology and disease. Stage and motor-pool dependence challenge uniform hyperexcitability toxicity, without excluding excessive calcium flux in other contexts.

[69] The 959-person riluzole dose-ranging trial supports survival benefit; the prespecified 100-mg comparison differs before versus after prognostic adjustment. Unadjusted p=.076 versus adjusted p=.002 and no separating functional scale deserve context; a multi-action drug is not selective mechanism proof.

Tally: 35 discriminating contrasts. Null and negative contrasts are discriminators, not positive threshold crossings. Reports and replications are not independent causal lines. Shared cohorts, experimental platforms, transgenic lineages and repeated outcomes do not constitute fully independent causal lines.

Cap audit, precedence and Β/Γ/Δ boundary

01-neurodegeneration thresholds bind the forced endogenous-lesion SC2 and precise SOD1 progression SC3. Γ constrains the inference to SC4/SC5 human disease dependency; it does not erase narrow genetic rescue. Conversely, improvement in engineered disease cannot transfer a higher score to sporadic primacy.

Gamma hard-rule audit: Cultured agonist toxicity and engineered receptor/transporter systems alone cannot carry sporadic-human primacy. Endogenous mediator perturbations retain real within-model value; forced disease background, developmental timing, cell role and drug target engagement limit broader inference.

SC1 cap: “Operational rule: association without temporal or perturbational proof caps at Β.” Β: selective transporter loss, editing defects and excitability patterns are reproducible but spatial/postmortem associations cannot determine disease dependency.

SC4 cap: “Maximum if mechanism is biologically plausible, supported by in vitro or simplified animal paradigms, but no disease-relevant necessity is shown in vivo.” Γ: human tissue and physiology plus model causality make the proposed obligate driver plausible, but no selective correction demonstrates sporadic-human disease dependency; clinical null/harm and stage-dependent protective excitation remain material separators.

SC5 cap: “Maximum if mechanism is biologically plausible, supported by in vitro or simplified animal paradigms, but no disease-relevant necessity is shown in vivo.” Γ: familial/cell-specific models and human-associated signatures do not converge on universal progression dependence. Riluzole benefit is real but multi-action; perampanel and ceftriaxone do not supply the missing selective clinical test.

SC1 field-valid definition: “ - Endogenous genetic deletion, suppression, or degron depletion of the proposed mediator in vivo - Selective pathway inhibition that changes onset/progression while preserving broader viability - Vagotomy-type natural experiment, only if confounding is rigorously controlled AND effect is disease-initiation relevant rather than merely associated” Positive full-scope result: no. Β: selective transporter loss, editing defects and excitability patterns are reproducible but spatial/postmortem associations cannot determine disease dependency.

SC2 field-valid definition: “ - Endogenous genetic deletion, suppression, or degron depletion of the proposed mediator in vivo - Selective pathway inhibition that changes onset/progression while preserving broader viability - Vagotomy-type natural experiment, only if confounding is rigorously controlled AND effect is disease-initiation relevant rather than merely associated” Positive full-scope result: yes. Ζ: distinct endogenous ADAR2 and spinal GLT1 lesions produce motor phenotypes; endogenous edited-GluR2 rescue in AR2 narrows the major ADAR2 off-target alternative. Membralin/EAAT2 rescue adds a different glial pathway. This scope is forced-lesion sufficiency, not spontaneous disease primacy.

SC3 field-valid definition: “ - Endogenous genetic deletion, suppression, or degron depletion of the proposed mediator in vivo - Selective pathway inhibition that changes onset/progression while preserving broader viability - Vagotomy-type natural experiment, only if confounding is rigorously controlled AND effect is disease-initiation relevant rather than merely associated” Positive full-scope result: yes. Ε: endogenous caspase-resistant EAAT2 knock-in changes functional progression and survival in the defined SOD1-G93A context. Transport kinetics and transgene-copy controls strengthen attribution, while absent onset/neuron-count effects and toxic-fragment mechanisms restrict the causal claim.

SC4 field-valid definition: “ - Endogenous genetic deletion, suppression, or degron depletion of the proposed mediator in vivo - Selective pathway inhibition that changes onset/progression while preserving broader viability - Vagotomy-type natural experiment, only if confounding is rigorously controlled AND effect is disease-initiation relevant rather than merely associated” Positive full-scope result: no. Γ: human tissue and physiology plus model causality make the proposed obligate driver plausible, but no selective correction demonstrates sporadic-human disease dependency; clinical null/harm and stage-dependent protective excitation remain material separators.

SC5 field-valid definition: “ - Endogenous genetic deletion, suppression, or degron depletion of the proposed mediator in vivo - Selective pathway inhibition that changes onset/progression while preserving broader viability - Vagotomy-type natural experiment, only if confounding is rigorously controlled AND effect is disease-initiation relevant rather than merely associated” Positive full-scope result: no. Γ: familial/cell-specific models and human-associated signatures do not converge on universal progression dependence. Riluzole benefit is real but multi-action; perampanel and ceftriaxone do not supply the missing selective clinical test.

Upward threshold ladder

SC1 Δ: “Requires at least one genuine causal perturbation in a disease-relevant in vivo system, or equivalent human natural experiment that materially supports the mechanism.” Satisfied: no. A selective, target-engaged perturbation matching SC1 with independently measured neuronal survival and functional trajectory, stage-matched controls and replication across prespecified contexts.

SC2 Δ: “Requires at least one genuine causal perturbation in a disease-relevant in vivo system, or equivalent human natural experiment that materially supports the mechanism.” Satisfied: yes.

SC2 Ε: “Requires causal support in a defined context, but with clear restriction by subtype, disease stage, model, or tissue.

Use Ε when there is a real causal contribution, but generalization to the entire disease class fails.” Satisfied: yes.

SC2 Ζ: “Requires: - Multiple independent causal lines in vivo - Replication across at least two relevant systems - Narrowing of major alternative models” Satisfied: yes.

SC2 Η: “Requires: - Strong convergent causal evidence across systems - Intervention-sensitive change in trajectory - No major unresolved contradiction about whether the mechanism is upstream versus downstream” Satisfied: no. A selective, target-engaged perturbation matching SC2 with independently measured neuronal survival and functional trajectory, stage-matched controls and replication across prespecified contexts.

SC3 Δ: “Requires at least one genuine causal perturbation in a disease-relevant in vivo system, or equivalent human natural experiment that materially supports the mechanism.” Satisfied: yes.

SC3 Ε: “Requires causal support in a defined context, but with clear restriction by subtype, disease stage, model, or tissue.

Use Ε when there is a real causal contribution, but generalization to the entire disease class fails.” Satisfied: yes.

SC3 Ζ: “Requires: - Multiple independent causal lines in vivo - Replication across at least two relevant systems - Narrowing of major alternative models” Satisfied: no. A selective, target-engaged perturbation matching SC3 with independently measured neuronal survival and functional trajectory, stage-matched controls and replication across prespecified contexts.

SC4 Δ: “Requires at least one genuine causal perturbation in a disease-relevant in vivo system, or equivalent human natural experiment that materially supports the mechanism.” Satisfied: no. A selective, target-engaged perturbation matching SC4 with independently measured neuronal survival and functional trajectory, stage-matched controls and replication across prespecified contexts.

SC5 Δ: “Requires at least one genuine causal perturbation in a disease-relevant in vivo system, or equivalent human natural experiment that materially supports the mechanism.” Satisfied: no. A selective, target-engaged perturbation matching SC5 with independently measured neuronal survival and functional trajectory, stage-matched controls and replication across prespecified contexts.

Upper ladder: Human interventions were examined against functional/survival endpoints. Riluzole is not a selective glutamate-pathway instrument; ceftriaxone lacks spinal EAAT2 engagement and perampanel has null/harm with attrition. Human EAAT2 variants and postmortem editing are not validated instruments for sporadic progression. These limitations block upper rungs for the nominal scope while leaving SC2 Ζ reachable.

Independence: ADAR2 and spinal transporter lesions fail differently, supporting the bounded SC2 set. Repeated AR2 rescues, high-copy SOD1 reports, overlapping RNA pathways, multiple endpoints and clinical cohort follow-ups are not independent human primacy lines. No universal cap is reapplied to negate the assembled bounded set.

Neuronal ADAR2 lesion with endogenous edited-receptor rescue [26]: Excludes indiscriminate ADAR2 substrate loss as sufficient explanation in the tested neuronal subset.

Glial spinal transporter deletion [61, 1]: Different cell role and lesion from ADAR2; does not exclude developmental or broad astrocytic confounds.

Endogenous cleavage-resistant mediator in SOD1 disease [60]: Maintains transporter kinetics and tests progression in a different insult; survival does not imply neuron preservation.

Human randomized and physiological tests [13, 16, 64, 69]: Exclude simple biomarker-to-benefit equivalence, but differ in selectivity, duration and target engagement.

Falsification and pitfalls

Uniform hyperexcitation toxicity is contradicted in defined presymptomatic spinal motor-neuron contexts. PMID24094105 and 32484501 report protection from increased excitation; preserved cell counts despite cleavage-resistant survival benefit in PMID28342750. Additional downgrade: False.

Broad translational efficacy prediction fails in the examined selective AMPA trial. PMID34191081 primary mixed model showed worse high-dose function with major attrition; ceftriaxone PMID25297012 was clinically null without engagement. Additional downgrade: False.

Excitability biomarker treated as cell death or therapeutic benefit. Ezogabine/perampanel acute metrics versus disease endpoints.

Species residue numbering mistaken for distinct mechanisms. Human EAAT2 D505N versus murine D504N in PMID28342750.

Clinical negative result treated as selective mechanism falsification. Ceftriaxone exposure without spinal EAAT2 target engagement.

Postmortem/pathway or engineered lesion generalized to human primacy. ADAR2/GLT1 sufficiency and tissue signatures versus SC4.

Provider summary substitutions and denominator errors. Consensus omitted perampanel primary trial, supplied a 1027 ceftriaxone table count and 514 narrative; originals govern.

Adversarial steelman: above, then below

Steelman Δ: receptor-encoded rescue is unusually specific and diverse glial interventions affect disease trajectories; human physiology can appear early. The missing step is a target-engaged sporadic-human dependency test, not more correlated signatures.

Steelman Β: human signatures are mainly associative and selective trial efficacy is absent. However, endogenous lesion/rescue and progression perturbations make the mechanism more than a biomarker association within bounded motor systems.

Reject Δ for SC4 because the positive perturbations do not match sporadic-human obligate progression scope; reject Β as the nominal synthesis because experimentally discriminating mechanistic support exists. Do not apply a second downgrade for contradictions already defining the scope.

Final score, causal direction and M/S/D

Preregistered scope-matched SC4 returns Γ. SC2 Ζ is a bounded forced-lesion result, and SC3 Ε is a SOD1 progression result. Weakest-link sensitivity is Β from descriptive SC1, so that aggregation would mix association depth with a distinct causal-driver question.

For the nominal common-ALS scope the evidence supports conditional amplification and maintenance, while engineered ADAR2/GLT1 lesions can initiate their own model. EAAT2-cleavage intervention acts after onset; human biomarkers do not identify an obligate progression bottleneck.

Momentum: Mechanistic only. Recent primary perturbation work in this corpus — RIPK1 glial-state perturbation (PMID40132594), astrocytic YAP/EAAT2 rescue in the poly-GA model (PMID40860154) and targeted STMN2 processing correction (PMID36927019) — tests mechanistic and functional boundaries. No trial or programme addressing the sporadic-human dependency boundary check is named, and no presently recruiting trial is claimed.

Stability: Stable. No named pending result is asserted to be likely to move the registered score imminently.

Divergence: Contested; no single implied-level arithmetic. These dimensions do not change level or confidence.

PROPOSED DECISIVE EXPERIMENTS

Prospectively stratify sporadic ALS by prespecified stage and cell-specific editing/clearance status, then compare selective CP-AMPA or EAAT2 correction with a mechanistically orthogonal RNA/axonal intervention in matched human-derived systems and an adult-onset disease model before a target-engaged clinical trajectory trial.

Readout: Receptor/clearance engagement, neuron counts, axon/NMJ integrity, motor function and survival measured separately. Controls: Edited-GluA2 versus nonediting rescue, transporter-dead control, physiological excitation preservation, isogenic comparator and blinded attrition-aware analysis. Supporting: Selective correction suppresses degeneration across prespecified contexts and adds no protection when the mediator is already normalized. Falsifying: Confirmed normalization leaves death/progression intact while orthogonal correction rescues it, or suppression worsens function in the proposed target context.

RESEARCH TIMELINE

KNOWLEDGE GAPS

A spinal astrocytic EAAT2 pharmacodynamic assay in living patients is missing from the examined ceftriaxone trial; CSF drug concentration cannot substitute.

Human ADAR2/GluA2 editing needs prospective causal ordering before cell loss rather than selected postmortem survivors.

CP-AMPA versus broadly suppressing physiological excitation must be separated by motor pool, compartment and disease stage.

EAAT2 transport loss must be distinguished from toxic CTE-SUMO1 signaling with transport-preserving matched perturbations.

Sporadic human subtype boundaries and genotype-specific mechanisms need prespecified replication, not pooling or responder-defined explanations.

The original perampanel abstract/Table 2 confidence-interval discrepancy and attrition-dependent sensitivity require explicit retention until a publisher correction or raw-data reanalysis resolves them.

Motor strength, NMJ loss, cell counts, excitability and survival should be measured independently; one cannot substitute for another.

Controlled negative and null results need the same source-depth scrutiny as positive model rescues.

METHODS AND CONSENSUS CONTRIBUTION

Consensus was used through the signed-in browser for discovery, counterevidence, research-gap and timeline suggestions, and attempted checks of specific indexed full-text passages. Returned Methods/Results passages were reconciled with original-paper passages where available; failed retrievals, source substitutions and unverified aspects are recorded in the case reconciliation. Successful passage checks are distinguished from provider summaries. Provider screening counts, citation counts and meters were not used as primary counts or HSEF scores. This source log records access depth; it does not claim complete-paper or supplement review. The monthly API allowance was conserved: zero Consensus API calls in this batch.

REVIEWER NOTES

69 primary reports examined; 6 selected original-body examinations. Direct original passages supersede Consensus summaries. Targeted Consensus explicitly failed to retrieve original ADAR2, spinal GLT1 and perampanel Methods/Results, using adjacent papers instead; ADAR2 and perampanel originals were obtained publicly here, GLT1 remains abstract-only. Consensus succeeded in checks of the EAAT2 endogenous knock-in/numbering, onset/progression distinction and ceftriaxone engagement limitation, independently reconciled. No API or Deep calls, no complete-paper/supplement audit, no independent blinded grading. Two linked errata are retained as unexamined detail limits.

Search leads, reviews, protocols and correction notices do not pad the primary count. Downloaded XML does not earn examination credit. Linked notices remain attached; unexamined correction details limit inference. This is a coordinator source/claim consistency assessment, not independent blinded calibration.

ADVERSARIAL REVIEW AND APPROVAL

Authoring model: Sol 6.1. Adversarial reviewer: Claude Opus 5.5 (Anthropic). Date: 2026-10-14. This is the revised (consensus-consistency) edition; findings marked regression were introduced by the revision and are not present in the earlier edition.

Scope of checks: all 69 REFERENCES PMIDs verified against PubMed metadata (69/69 resolved to the stated title, first author, journal and year; the two linked errata are correctly recorded as parent-source status rather than as numbered sources; no retraction or expression-of-concern notices found); 12 load-bearing claims spot-checked against the cited abstracts and the retrieved trial records; scoring logic re-derived against references/hsef-framework.md and SKILL.md Steps 2–3 (six universal caps, scope-matched aggregation, Ζ independence basis, Β/Γ/Δ boundary, Momentum/Stability/Divergence artifacts).

Rejected findings (checked, no change): - SC2 at Ζ. independence_basis is present and names four lines with the distinct systematic error each excludes, as v5.2 requires, and the subclaim's scope is explicitly forced-lesion sufficiency rather than spontaneous disease primacy. The neuronal ADAR2 lesion with endogenous edited-GluR2 rescue and the astrocytic spinal GLT1 deletion fail differently, and the record itself discloses that the glial line does not exclude developmental or broad astrocytic confounds. Debatable but not forced by the framework text; SC2 does not gate the headline under the preregistered rule. - Aggregation. Scope-matched returns the highest subclaim whose scope matches the central claim's sporadic-human-primacy scope, which is SC4 at Γ; SC2 (Ζ) and SC3 (Ε) are narrower and are reported separately. Weakest-link Β and primary-subclaim Γ are reported as required. - Validator WARN v5.claim_form entry_form is 'phenomenon'. The registered claim states a mechanism plus its consequence ("is the causal driver of motor-neuron death in ALS"), so the warning is a false positive under the standing convention. - Batch-wide revision artifact reported by the lead (a spliced Consensus-consistency block left beside preserved REVIEWER NOTES asserting that no Consensus work was performed): not present in this case. The spliced block here is the "Consensus provenance reconciliation" section, and the preserved METHODS AND CONSENSUS CONTRIBUTION and REVIEWER NOTES both affirm signed-in browser use, record which retrievals failed, and state only that zero Consensus API calls were made — which is consistent, not contradictory. No scoping edit was needed. - review_metadata.reviewer reading "Codex" in the score card is house provenance and was left unedited. - Reference 16 year 2022 versus PubMed 2021 — print/issue versus e-pub, within convention, and the timeline already flags it as issue-year chronology. - PubMed title fields dropping italicised gene names (STMN2 in reference 49, GLT1/GluR2 symbols elsewhere) — PubMed rendering artifact. - Numeric claims re-checked and correct: ceftriaxone 513 randomized (340 active, 173 placebo) with no stage-3 functional or survival benefit (PMID 25297012); perampanel 66 randomized / 65 analyzed, 7/21 versus 18/22 completion, −8.4 ALSFRS-R difference with an abstract interval (−13.9 to −2.9) that differs from Table 2 (PMID 34191081); riluzole 155 participants (PMID 8302340) and 959 participants with unadjusted p=0.076 versus adjusted p=0.002 (PMID 8676624); talampanel 59 randomized with non-significant trends (PMID 19961264); ezogabine 65 randomized (PMID 33226425); EAAT2-D504N extends progression and lifespan without changing onset (PMID 28342750); Hoxb8-Cre spinal GLT1 deletion causes motor-neuron death, abstract only (PMID 29458024).

Residual limitations: the spinal GLT1 lesion that carries part of the SC2 independence basis remains abstract-only, so its controls are unaudited; two linked errata (PMID 38890465, PMID 36480942) are recorded but their contents were not examined; access depth is unchanged at 6 partial-body and 63 abstract/status examinations.

Approval: Following adversarial review and the corrections listed above, the revised document is approved. — Claude Opus 5.5 (Anthropic), 2026-10-14.

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Source-specific evidence cards

[1] Membralin deficiency dysregulates astrocytic glutamate homeostasis leading to ALS-like impairment.

Shows: Astrocytic membralin loss lowers EAAT2 and causes motor phenotypes; restoring EAAT2 or membralin protects in engineered settings.

Does not show: Membralin regulates broader inflammatory pathways; forced deletion and SOD1 rescue do not establish sporadic human primacy.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[2] Small-molecule activator of glutamate transporter EAAT2 translation provides neuroprotection.

Shows: EAAT2 translational activator improves motor function and survival in a mouse ALS model.

Does not show: PKC/YB1 effects and engineered background constrain attribution; clinical spinal engagement is untested.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC5.

[3] Cells over-expressing EAAT2 protect motoneurons from excitotoxic death in vitro.

Shows: EAAT2 overexpression protects cocultured motor neurons from glutamate exposure.

Does not show: Forced receptor milieu and transporter expression do not establish endogenous ALS necessity.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[4] Amyotrophic lateral sclerosis-linked glutamate transporter mutant has impaired glutamate clearance capacity.

Shows: An EAAT2 N206S variant detected in an ALS patient impairs transport-related properties in assays.

Does not show: A single detected variant is not segregation evidence or an explanation of common sporadic ALS.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1.

[5] An unrecognized mechanism of self-protection in degenerating neurons mediated by astrocytic YAP through Wnts/β-catenin/EAAT2 signaling in C9orf72-poly-GA mice.

Shows: Astrocytic YAP loss exacerbates poly-GA-model phenotypes; LDN-212320 restores EAAT2 and partially rescues motor and neuronal readouts.

Does not show: Neonatal AAV-GA100 forces the disease insult; YAP has broad effects and neuronal Wnt induction is a protective response. This is not upstream sporadic primacy.

Access/status: Complete primary abstract and linked-status metadata examined. Selected body sections: 2:Results:paragraph0, 2:Results:paragraph2, 2:Results:paragraph8, 2:Results:paragraph9, 2:Results:paragraph13, 2:Results:paragraph14, 2:Results:paragraph15. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[6] Over-expression of the human EAAT2 glutamate transporter within neurons of mouse organotypic hippocampal slice cultures leads to increased vulnerability of CA1 pyramidal cells.

Shows: Neuronal EAAT2 overexpression increases glutamate injury in hippocampal slice experiments.

Does not show: Non-ALS cell-role comparator; does not refute appropriate astrocytic transporter restoration.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[7] Glutamate transporter gene expression in amyotrophic lateral sclerosis motor cortex.

Shows: ALS specimens show marked EAAT2 protein and transport loss without corresponding mRNA changes.

Does not show: Postmortem association leaves degradation, downstream damage and reverse causation unresolved.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[8] Motor neuron impairment mediated by a sumoylated fragment of the glial glutamate transporter EAAT2.

Shows: Forced CTE-SUMO1 expression alters astrocytes and damages cocultured motor-neuron/axon readouts.

Does not show: A toxic transporter fragment may act beyond clearance; cultured fragment expression is not physiological necessity.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3.

[9] Increased glutamine synthetase but normal EAAT2 expression in platelets of ALS patients.

Shows: Platelet EAAT2 protein and uptake are not reduced in this ALS comparison.

Does not show: Peripheral platelets do not directly test spinal astrocyte transporter dysfunction.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1.

[10] Caspase-3 cleaves and inactivates the glutamate transporter EAAT2.

Shows: Caspase-3 cleaves EAAT2 and impairs transport; mutant-SOD1 contexts contain the truncated species.

Does not show: Cleavage association is not proof of disease necessity; biochemical human D505 numbering must be separated from mouse D504.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3.

[11] Intron 7 retention and exon 9 skipping EAAT2 mRNA variants are not associated with amyotrophic lateral sclerosis.

Shows: EAAT2 splice variants occur in ALS and non-ALS tissue; tested CSF assays did not find the proposed transcripts.

Does not show: Specific splice-variant attribution fails; neither null CSF transcripts nor this finding excludes other transporter lesions.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1.

[12] Mechanism of ceftriaxone induction of excitatory amino acid transporter-2 expression and glutamate uptake in primary human astrocytes.

Shows: Ceftriaxone induces EAAT2 via NF-kappaB in human fetal astrocytes; RNAi removes the uptake effect.

Does not show: Fetal isolated cells are not adult spinal target engagement or clinical efficacy.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[13] Safety and efficacy of ceftriaxone for amyotrophic lateral sclerosis: a multi-stage, randomised, double-blind, placebo-controlled trial.

Shows: The ceftriaxone phase-3 dataset contains 513 participants (340 active and 173 placebo); functional decline and survival were not significantly improved.

Does not show: CSF exposure did not establish EAAT2 activation; hepatobiliary toxicity and treatment discontinuation constrain a mechanism-level negative inference. Consensus table 1027 and narrative 514 are not the final analysis denominator.

Access/status: Complete primary abstract and linked-status metadata examined. Selected body sections: 2:Results:paragraph0, 2:Results:paragraph1, 2:Results:paragraph4, 2:Results:paragraph5, 3:Discussion:paragraph7. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[14] Rescue of amyotrophic lateral sclerosis phenotype in a mouse model by intravenous AAV9-ADAR2 delivery to motor neurons.

Shows: AAV9-ADAR2 delivery rescues motor-neuron loss, function and TDP-43 distribution in conditional ADAR2-deficient mice.

Does not show: Restoring the gene deliberately deleted in AR2 is a matched model test, not intervention in spontaneous human ALS.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[15] The AMPA receptor antagonist perampanel robustly rescues amyotrophic lateral sclerosis (ALS) pathology in sporadic ALS model mice.

Shows: Perampanel protects motor and neuronal readouts in AR2 mice.

Does not show: Shares the ADAR2 lesion lineage with other AR2 reports; model rescue does not establish human tolerability or benefit.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[16] Randomized phase 2 study of perampanel for sporadic amyotrophic lateral sclerosis.

Shows: Perampanel randomized 66 patients and analyzed 65; only 7/21 in the 8-mg group completed 48 weeks versus 18/22 placebo. Primary mixed-model ALSFRS-R change was worse at 8 mg.

Does not show: Small sample, attrition and symptomatic adverse effects limit attribution to accelerated neuronal death. Table 2 CI for the -8.4 difference is -15.0 to -1.8; abstract gives a different CI. LOCF covariance sensitivity did not retain significance.

Access/status: Complete primary abstract and linked-status metadata examined. Selected body sections: 1:Methods:paragraph2, 1:Methods:paragraph3, 1:Methods:paragraph5, 1:Methods:paragraph8, 2:Results:paragraph0, 2:Results:paragraph6, 2:Results:paragraph8, 2:Results:paragraph27. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[17] Cortical excitability threshold can be increased by the AMPA blocker Perampanel in amyotrophic lateral sclerosis.

Shows: Single-dose perampanel changes cortical motor threshold in a small ALS experiment.

Does not show: Acute cortical physiology is not motor-neuron survival or slowed decline; curtailed recruitment limits dose comparison.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC5.

[18] The RNA-binding protein FUS/TLS undergoes calcium-mediated nuclear egress during excitotoxic stress and is required for GRIA2 mRNA processing.

Shows: Glutamate exposure causes calcium-dependent FUS/TDP-43 relocalization and GRIA2-related responses.

Does not show: Forced exposure permits feedback mechanisms; it does not order the initiating lesion in ALS.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[19] Testing of the therapeutic efficacy and safety of AMPA receptor RNA aptamers in an ALS mouse model.

Shows: ICV AMPA aptamers improve motor and neuronal readouts in AR2 mice.

Does not show: Same conditional ADAR2 platform; no independent sporadic-human causal replication.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[20] AMPA receptor calcium permeability, GluR2 expression, and selective motoneuron vulnerability.

Shows: Rat motor and dorsal-horn cultures show comparable whole-cell AMPA calcium permeability despite different vulnerability.

Does not show: Whole-cell averages do not exclude a toxic receptor subset, and developmental rat cells are not human ALS neurons.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC5.

[21] Altered presymptomatic AMPA and cannabinoid receptor trafficking in motor neurons of ALS model mice: implications for excitotoxicity.

Shows: SOD1-G93A motor neurons show presymptomatic changes in synaptic GluR1/GluR2 and CB1 distribution.

Does not show: Trafficking and inferred permeability are not selective receptor blockade with a disease endpoint.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1.

[22] Phosphorylated TDP-43 becomes resistant to cleavage by calpain: A regulatory role for phosphorylation in TDP-43 pathology of ALS/FTLD.

Shows: Phosphorylated TDP-43 and calpain-generated fragments resist further cleavage.

Does not show: Biochemical persistence does not establish that excitotoxic calcium flux caused the human disease.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[23] Morphological features and responses to AMPA receptor-mediated excitotoxicity of mouse motor neurons: comparison in purified, mixed anterior horn or motor neuron/glia cocultures.

Shows: AMPA/kainate toxicity and apoptotic responses depend on culture composition and agonist concentration.

Does not show: Glial maturation and exposure alter the result; cultured toxicity cannot carry organismal primacy.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[24] Amyotrophic lateral sclerosis 2-deficiency leads to neuronal degeneration in amyotrophic lateral sclerosis through altered AMPA receptor trafficking.

Shows: Alsin deficiency alters GRIP1 and surface GluR2 and increases glutamate susceptibility.

Does not show: Juvenile ALS2 and receptor susceptibility are a specific context, not common sporadic disease dependency.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[25] Astrocytes regulate GluR2 expression in motor neurons and their vulnerability to excitotoxicity.

Shows: Ventral astrocytes regulate strain-dependent GluR2 and motor-neuron susceptibility; mutant SOD1 disrupts this capacity.

Does not show: Rat strain and mutant-protein context restrict generalization and do not isolate a universal initiating pathway.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[26] Induced loss of ADAR2 engenders slow death of motor neurons from Q/R site-unedited GluR2.

Shows: Conditional ADAR2 loss in a cholinergic motor-neuron subset causes slow neuronal loss; endogenous edited-GluR2 replacement preserves neurons and motor function despite ADAR2 absence.

Does not show: Developmental Cre and selective lesion define the scope; oculomotor neurons resist reduced editing. Original cell counts were blinded; rescue at six months is not a clinical sporadic-ALS test.

Access/status: Complete primary abstract and linked-status metadata examined. Selected body sections: 0:Publisher HTML paragraphs:paragraph15, 0:Publisher HTML paragraphs:paragraph16, 0:Publisher HTML paragraphs:paragraph25, 0:Publisher HTML paragraphs:paragraph33, 0:Publisher HTML paragraphs:paragraph41, 0:Publisher HTML paragraphs:paragraph42, 0:Publisher HTML paragraphs:paragraph43, 0:Publisher HTML paragraphs:paragraph44, 0:Publisher HTML paragraphs:paragraph45. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[27] Ca(2+)-permeable AMPA receptors and selective vulnerability of motor neurons.

Shows: Kainate selectively kills calcium-permeable-AMPA-positive motor neurons; AMPA and receptor-subset blockade prevent cultured death.

Does not show: Pharmacologically forced exposure is not an ALS trajectory; GluR2 immunoreactivity does not itself imply receptor impermeability.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[28] Calcium-permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors: a molecular determinant of selective vulnerability in amyotrophic lateral sclerosis.

Shows: In situ assays did not detect GluR2 mRNA in normal human spinal motor neurons and predict atypical receptor composition.

Does not show: Detection sensitivity and inference from transcript to assembled receptor constrain the claim; normal tissue does not establish ALS mechanism.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1.

[29] GluR2 AMPA receptor subunit expression in motoneurons at low and high risk for degeneration in amyotrophic lateral sclerosis.

Shows: Normal rat oculomotor and hypoglossal neurons have comparable GluR2 transcript/protein despite differing disease vulnerability.

Does not show: Cross-species negative comparator challenges simple expression explanations rather than all calcium-permeable-AMPA mechanisms.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC5.

[30] VEGF protects motor neurons against excitotoxicity by upregulation of GluR2.

Shows: VEGF induces GluR2 and lowers AMPA calcium permeability and vulnerability in cultured neurons; ICV treatment induces ventral-spinal expression.

Does not show: VEGF has broad effects; receptor induction in vivo is not isolated ALS survival causation.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[31] Focal degeneration of astrocytes in amyotrophic lateral sclerosis.

Shows: Mutant-SOD1 astrocytes are mGluR5-vulnerable; in vivo mGluR5 blockade slows astrocyte damage and modestly delays disease.

Does not show: Interacting astrocyte degeneration is context specific and does not prove motor-neuron AMPA primacy.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[32] Calcium-influx increases SOD1 aggregates via nitric oxide in cultured motor neurons.

Shows: Calcium ionophore increases mutant-SOD1 aggregation through nitric-oxide-linked responses in a cell line.

Does not show: Forced calcium loading and transfected SOD1 do not identify physiological ALS ordering.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[33] Cortical hyperexcitability precedes lower motor neuron dysfunction in ALS.

Shows: Cortical hyperexcitability was found in 24 ALS patients despite preserved tested APB lower-motor-unit measures.

Does not show: Within-patient anatomical contrast is not pre-disease longitudinal intervention; other motor pools and occult denervation remain possible.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[34] Hyperexcitability of cultured spinal motoneurons from presymptomatic ALS mice.

Shows: Embryonic/neonatal SOD1-G93A cultured motor neurons have greater intrinsic firing gain.

Does not show: Developmental mutant overexpression and current injection are not proof of excessive synaptic glutamate in adult ALS.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1.

[35] Synaptic restoration by cAMP/PKA drives activity-dependent neuroprotection to motoneurons in ALS.

Shows: Presymptomatic mutant-SOD1 motor-neuron excitation is reduced; independent chemogenetic signaling/activity manipulation restores synapses and improves pathological readouts.

Does not show: Does not refute cortical hyperexcitability or calcium toxicity in other stages; it contradicts uniform benefit from suppressing motor-neuron excitation.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[36] Cortical hyperexcitability and disease spread in amyotrophic lateral sclerosis.

Shows: Fifty sporadic-ALS patients show cortical hyperexcitability patterns aligned with subsequently mapped contiguous spread.

Does not show: Longitudinal association does not selectively manipulate glutamatergic transmission or exclude shared pathology.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[37] Cortical interneuron-mediated inhibition delays the onset of amyotrophic lateral sclerosis.

Shows: Chemogenetic cortical parvalbumin-interneuron activation reduces pyramidal hyperexcitability and improves onset, neuronal and survival outcomes in SOD1 mice.

Does not show: Cortical circuit modulation differs from spinal motor-neuron silencing; engineered disease and broad network effects limit human inference.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[38] Axonal Dysfunction Precedes Motor Neuronal Death in Amyotrophic Lateral Sclerosis.

Shows: Nerve-excitability measures are abnormal in 140 ALS patients, including subgroups with normal CMAP.

Does not show: CMAP is an indirect and insensitive loss measure; sodium/potassium conductances are not uniquely glutamate-driven.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1.

[39] A controlled trial of riluzole in amyotrophic lateral sclerosis. ALS/Riluzole Study Group.

Shows: A 155-patient placebo-controlled riluzole trial found a survival advantage and slower strength deterioration.

Does not show: Riluzole has multiple receptor/channel actions; benefit does not identify EAAT2 or AMPA as the necessary causal mediator.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[40] Riluzole has no acute effect on motor unit parameters in ALS.

Shows: Acute randomized crossover testing did not show a riluzole effect on assessed motor-unit parameters.

Does not show: Acute physiological null does not negate long-term survival benefit; abstract reports limited outcome detail.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC5.

[41] CSF from amyotrophic lateral sclerosis patients produces glutamate independent death of rat motor brain cortical neurons: protection by resveratrol but not riluzole.

Shows: ALS CSF damages cultured rat cortical neurons through an apparently glutamate-independent route; riluzole does not protect.

Does not show: Cross-species cultured bioassay and pleiotropic resveratrol rescue do not establish the alternative mechanism in patients.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[42] A phase II trial of talampanel in subjects with amyotrophic lateral sclerosis.

Shows: Talampanel phase II randomized 59 ALS participants; favorable numerical strength/ALSFRS trends did not reach statistical significance.

Does not show: Small trial and sedation/dizziness constrain inference; numerical trends are not demonstrated disease modification.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[43] Single-cell transcriptomic and functional studies identify glial state changes and a role for inflammatory RIPK1 signaling in ALS pathogenesis.

Shows: Single-nucleus spinal profiles identify inflammatory glial states; RIPK1 blockade delays SOD1-mouse symptoms and modulates responses.

Does not show: Independent inflammatory pathway is a rival/convergent contributor; human secreted-marker modulation is not patient survival causation.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[44] Kir4.1-Dependent Astrocyte-Fast Motor Neuron Interactions Are Required for Peak Strength.

Shows: Astrocytic Kir4.1 loss reduces peak strength and changes fast-motor-neuron size but is dispensable for survival even in SOD1 background.

Does not show: Distinct potassium-support pathway; illustrates strength/death decoupling rather than refuting astrocytic glutamate clearance.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[45] GLT1 gene delivery based on bone marrow-derived cells ameliorates motor function and survival in a mouse model of ALS.

Shows: GLT1-expressing transplanted marrow-derived cells improve mouse motor behavior and survival and shift inflammatory markers.

Does not show: Transplantation and immune-state changes prevent clean attribution to astrocytic transporter correction alone.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC5.

[46] Translational profiling identifies a cascade of damage initiated in motor neurons and spreading to glia in mutant SOD1-mediated ALS.

Shows: Cell-type translational profiles place early SOD1-linked synaptic/metabolic/ER changes in motor neurons before later glial changes.

Does not show: SOD1 ordering is not common sporadic ordering; profiles do not directly block glutamate as a downstream contributor.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[47] TDP-43 represses cryptic exon inclusion in the FTD-ALS gene UNC13A.

Shows: TDP-43 loss activates a UNC13A cryptic exon; ALS-risk variants increase mis-splicing and reduce protein.

Does not show: Supports a functional genetic/RNA rival, not proof that all neuronal death is independent of excitotoxicity.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[48] TDP-43 loss and ALS-risk SNPs drive mis-splicing and depletion of UNC13A.

Shows: Independent experiments link UNC13A risk variants to TDP-43-dependent cryptic splicing and protein depletion.

Does not show: Related human tissues and TDP-43 platforms may overlap; linked erratum PMID38890465 is recorded but details not examined.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. ErratumIn: PMID38890465. Subclaims: SC4, SC5.

[49] Mechanism of STMN2 cryptic splice-polyadenylation and its correction for TDP-43 proteinopathies.

Shows: STMN2 cryptic processing is corrected by targeted reagents; axonal regeneration/lysosome trafficking recover in deficient human motor neurons.

Does not show: Functional axon repair and engineered humanized mice are not broad clinical survival proof.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[50] Premature polyadenylation-mediated loss of stathmin-2 is a hallmark of TDP-43-dependent neurodegeneration.

Shows: Loss of TDP-43 reduces STMN2 through premature polyadenylation; STMN2 restoration rescues axonal regenerative capacity.

Does not show: Axonal regeneration is a bounded functional endpoint, not death prevention in all ALS.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[51] ALS-implicated protein TDP-43 sustains levels of STMN2, a mediator of motor neuron growth and repair.

Shows: TDP-43/STMN2 perturbation and stabilization connect transcript loss to neurite and regeneration deficits.

Does not show: Shares disease pathway with other STMN2 reports; restoration is not independent clinical causality.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[52] Loss of mouse Stmn2 function causes motor neuropathy.

Shows: Endogenous Stmn2 loss causes denervation and motor dysfunction; human STMN2 BAC rescues motor phenotypes.

Does not show: Different axonal-support lesion, not selective neuron death caused by glutamate. Linked erratum PMID36480942 remains an unexamined detail.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. ErratumIn: PMID36480942. Subclaims: SC4, SC5.

[53] Sarm1 deletion suppresses TDP-43-linked motor neuron degeneration and cortical spine loss.

Shows: Sarm1 deletion attenuates TDP-43-model axon/neuromuscular-junction and neuron loss, but not behavioral deficits.

Does not show: Mixed FTD-like model and sex-related viability affect scope; phenotype classes must not be collapsed.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[54] AMPA receptor activation causes preferential mitochondrial Ca²⁺ load and oxidative stress in motor neurons.

Shows: AMPA stimulation preferentially loads motor-neuron mitochondria and produces sustained oxidative stress.

Does not show: Forced cultured challenge supports calcium/mitochondrial plausibility without endogenous disease necessity.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[55] An open label pilot study of the safety and tolerability of perampanel in amyotrophic lateral sclerosis.

Shows: All six ALS participants had adverse events on perampanel; four withdrew and the pilot stopped.

Does not show: Tiny uncontrolled tolerability study cannot estimate efficacy but challenges unqualified translational optimism.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[56] Human amyotrophic lateral sclerosis excitability phenotype screen: Target discovery and validation.

Shows: A target-annotated compound screen identifies AMPA, Kv7 and D2 modulation of patient-derived motor-neuron excitability.

Does not show: Cell excitability screens are target-discovery evidence, not organismal neuronal rescue.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[57] Astrocytes expressing ALS-linked mutant FUS induce motor neuron death through release of tumor necrosis factor-alpha.

Shows: Mutant-FUS astrocyte conditioned medium kills neurons; TNF neutralization blocks toxicity and receptor composition changes accompany it.

Does not show: Tagged forced FUS and culture constrain inference; inflammatory and AMPA routes can be coupled rather than exclusive.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[58] Motor neuron-derived microRNAs cause astrocyte dysfunction in amyotrophic lateral sclerosis.

Shows: Motor-neuron-derived extracellular miR-218 lowers astrocytic EAAT2; antisense inhibition mitigates changes in ALS mice.

Does not show: Shows an upstream neuron-to-astrocyte feedback alternative; transporter-marker rescue is not demonstrated survival benefit in the examined abstract.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[59] Oligodendroglia metabolically support axons and contribute to neurodegeneration.

Shows: Disrupting oligodendroglial MCT1 injures axons/neurons, and MCT1 is reduced in ALS materials.

Does not show: Independent metabolic-support route; its presence does not exclude interacting glutamate stress or establish universal primacy.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[60] Mutation of the caspase-3 cleavage site in the astroglial glutamate transporter EAAT2 delays disease progression and extends lifespan in the SOD1-G93A mouse model of ALS.

Shows: Mouse endogenous EAAT2-D504N blocks cleavage; progression and lifespan improve modestly in SOD1-G93A mice with matched transgene-copy checks.

Does not show: Human plasmid D505N and mouse D504N name homologous sites. Onset and measured P150 motor-neuron counts did not change; reducing toxic CTE-SUMO1 is not uniquely restoring glutamate clearance.

Access/status: Complete primary abstract and linked-status metadata examined. Selected body sections: 2:RESULTS:paragraph1, 2:RESULTS:paragraph2, 2:RESULTS:paragraph6, 2:RESULTS:paragraph8, 2:RESULTS:paragraph9, 2:RESULTS:paragraph10, 2:RESULTS:paragraph13, 2:RESULTS:paragraph14. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC5.

[61] Spinal cord-specific deletion of the glutamate transporter GLT1 causes motor neuron death in mice.

Shows: Hoxb8-Cre spinal GLT1 deletion produces motor deficits and motor-neuron loss.

Does not show: Original abstract supports sufficiency within forced spinal deletion; Methods/Results not retrieved by Consensus or local PMC. Developmental timing and matched rescue details remain unverified.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2.

[62] TDP-43 pathology in sporadic ALS occurs in motor neurons lacking the RNA editing enzyme ADAR2.

Shows: ADAR2-negative ALS motor neurons contain phosphorylated cytoplasmic TDP-43 and lack normal nuclear TDP-43.

Does not show: Colocalization does not order the lesions; surviving postmortem cells are selected.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[63] Selective loss of glial glutamate transporter GLT-1 in amyotrophic lateral sclerosis.

Shows: Matched-age/postmortem-delay specimens show selective GLT1 protein loss compared with other transporters and stable GFAP.

Does not show: Authors explicitly permit primary defect, downregulation or other toxicity; stable GFAP is not proof of intact astrocytic function.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[64] Effect of Ezogabine on Cortical and Spinal Motor Neuron Excitability in Amyotrophic Lateral Sclerosis: A Randomized Clinical Trial.

Shows: Ezogabine randomized 65 ALS participants, changes cortical/axonal excitability, and showed no significant ALSFRS-R, vital-capacity or strength effect over the short trial.

Does not show: Only four weeks at full dose; this cannot establish durable efficacy or refute a long-term effect. Active-arm discontinuation and biomarker selection constrain generalization.

Access/status: Complete primary abstract and linked-status metadata examined. Selected body sections: 0:Publisher HTML paragraphs:paragraph45, 0:Publisher HTML paragraphs:paragraph47, 0:Publisher HTML paragraphs:paragraph49, 0:Publisher HTML paragraphs:paragraph52, 0:Publisher HTML paragraphs:paragraph55, 0:Publisher HTML paragraphs:paragraph60, 0:Publisher HTML paragraphs:paragraph69, 0:Publisher HTML paragraphs:paragraph70, 0:Publisher HTML paragraphs:paragraph77, 0:Publisher HTML paragraphs:paragraph79. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC5.

[65] Acute Effects of Riluzole and Retigabine on Axonal Excitability in Patients With Amyotrophic Lateral Sclerosis: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial.

Shows: An 18-person acute crossover shows retigabine axonal-excitability effects but no riluzole effect on those metrics.

Does not show: Single-dose physiology cannot identify the mediator of long-term survival benefit.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC5.

[66] Intrinsic membrane hyperexcitability of amyotrophic lateral sclerosis patient-derived motor neurons.

Shows: SOD1, C9orf72 and FUS iPSC neurons show hyperexcitability; isogenic SOD1 correction removes it and retigabine improves mutant-cell survival.

Does not show: Genetic correction validates genotype dependence, while immature cultures and Kv7 effects do not prove common adult glutamatergic primacy.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC5.

[67] Neuroprotection through excitability and mTOR required in ALS motoneurons to delay disease and extend survival.

Shows: Enhancing susceptible motor-neuron excitability/mTOR protects in SOD1 models; reducing it worsens pathology and disease.

Does not show: Stage and motor-pool dependence challenge uniform hyperexcitability toxicity, without excluding excessive calcium flux in other contexts.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[68] Amyotrophic lateral sclerosis is a distal axonopathy: evidence in mice and man.

Shows: SOD1 mice show distal denervation before axon and cell-body loss; one human autopsy has denervation with preserved-appearing neurons.

Does not show: Temporal compartment ordering is limited by one human case and does not test glutamate directly; distal injury is not necessarily glutamate independent.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

[69] Dose-ranging study of riluzole in amyotrophic lateral sclerosis. Amyotrophic Lateral Sclerosis/Riluzole Study Group II.

Shows: The 959-person riluzole dose-ranging trial supports survival benefit; the prespecified 100-mg comparison differs before versus after prognostic adjustment.

Does not show: Unadjusted p=.076 versus adjusted p=.002 and no separating functional scale deserve context; a multi-action drug is not selective mechanism proof.

Access/status: Complete primary abstract and linked-status metadata examined. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4, SC5.

Documentary record

Every grade on this site is reproducible from its record. The files below are the posted edition exactly as assessed.

• ADVERSARIAL_REVIEW.md
• SHA256.txt
• adversarial-findings.json
• codex-correction-provenance.json
• consensus-addendum.md
• consensus-validation.json
• edition-approval-audit.json
• excitotoxicity-als.review.md
• excitotoxicity-als.scorecard.json
• reader-summary.json
• validation-report.json
• validation-round2-2026-10-14.json
• validation.txt

Sources: 69 · load-bearing claims: 75 · verified: 75 · unverified: 0 · contradicted: 0 · schema 5.3