{"ranked_hypotheses":[{"title":"Tau missorting transitions into an autonomous tau-seeding state after transient Aβ exposure","description":"Transient Aβ exposure induces dendritic tau missorting that then converts into a locally self-propagating tau oligomer/seeding program. After verified Aβ clearance, continued degeneration is driven by tau seed formation, templated misfolding, and trans-synaptic spread rather than by ongoing amyloid signaling.","target_gene":"MAPT","dimension_scores":{"evidence_strength":0.78,"novelty":0.72,"feasibility":0.83,"therapeutic_potential":0.84,"mechanistic_plausibility":0.82,"druggability":0.8,"safety_profile":0.62,"competitive_landscape":0.58,"data_availability":0.74,"reproducibility":0.7},"composite_score":0.74,"evidence_for":[{"claim":"Tau oligomer formation and propagation are well supported, making an autonomous post-trigger seeded state biologically plausible.","pmid":"23882255"},{"claim":"Aβ can heterotypically seed or accelerate tau propagation, supporting an initiator-to-seeding transition model.","pmid":"26739002"},{"claim":"Aβ oligomers induce tau missorting and spine pathology, providing the upstream state from which autonomous seeding could emerge.","pmid":"20826658"}],"evidence_against":[{"claim":"Direct proof that transient Aβ exposure alone creates a self-sustaining tau-seeding state after complete Aβ removal remains limited.","pmid":"26739002"},{"claim":"Many tau-seeding systems rely on overexpression or persistent pathology, leaving Aβ-independent persistence unresolved.","pmid":"23882255"}]},{"title":"Microglia and complement sustain post-Aβ neurodegeneration after tau missorting is established","description":"Aβ initiates tau missorting, but persistent degeneration is then maintained by activated microglia through C1q/C3-CR3-mediated pruning and inflammatory remodeling. This model best explains continued synapse loss after amyloid reduction, though it may maintain degeneration more clearly than tau polarity failure itself.","target_gene":"C1QA,C1QB,C1QC,C3,ITGAM,TREM2,TYROBP","dimension_scores":{"evidence_strength":0.76,"novelty":0.6,"feasibility":0.8,"therapeutic_potential":0.73,"mechanistic_plausibility":0.79,"druggability":0.7,"safety_profile":0.48,"competitive_landscape":0.55,"data_availability":0.77,"reproducibility":0.72},"composite_score":0.69,"evidence_for":[{"claim":"Microglia-mediated synapse loss is strongly implicated in AD, supporting a persistent post-amyloid pruning mechanism.","pmid":"29563239"},{"claim":"Microglia drive APOE-dependent neurodegeneration in tauopathy, showing that glial states can sustain injury downstream of primary triggers.","pmid":"31601677"},{"claim":"Tau-oligomer-associated synapse elimination by microglia and astrocytes has been observed in AD tissue.","pmid":"37812432"}],"evidence_against":[{"claim":"Evidence supports ongoing synapse loss more than direct maintenance of dendritic tau missorting after Aβ removal.","pmid":"29563239"},{"claim":"Complement blockade may reduce downstream pruning without normalizing tau polarity, limiting fit to the core persistence question.","pmid":"31601677"}]},{"title":"Fyn-anchored dendritic tau/NMDAR signaling persists after transient Aβ exposure","description":"Aβ drives tau into dendritic spines, where tau binds Fyn and stabilizes a PSD95-NMDAR-associated excitotoxic scaffold. Once assembled, this complex may persist after Aβ clearance and maintain calcium dysregulation, hyperexcitability, and synaptic degeneration.","target_gene":"MAPT,FYN,DLG4,GRIN2B","dimension_scores":{"evidence_strength":0.71,"novelty":0.58,"feasibility":0.79,"therapeutic_potential":0.66,"mechanistic_plausibility":0.8,"druggability":0.63,"safety_profile":0.5,"competitive_landscape":0.57,"data_availability":0.76,"reproducibility":0.7},"composite_score":0.67,"evidence_for":[{"claim":"Dendritic tau mediates Aβ toxicity via Fyn-dependent NMDA receptor signaling, strongly supporting this signaling axis.","pmid":"20655099"},{"claim":"Aβ oligomers induce tau missorting, local calcium rise, and spine loss, consistent with a feed-forward excitotoxic framework.","pmid":"20826658"},{"claim":"Soluble Aβ oligomers drive tau mislocalization to spines and receptor-signaling deficits.","pmid":"24713000"}],"evidence_against":[{"claim":"Existing evidence mainly shows that tau is required for Aβ toxicity, not that the tau-Fyn scaffold persists once Aβ is fully absent.","pmid":"20655099"},{"claim":"Persistent calcium dysregulation could reflect irreversible spine injury or residual Aβ rather than a self-maintained tau-Fyn complex.","pmid":"24713000"}]},{"title":"A post-trigger CDK5-dominant kinase feedback loop maintains dendritic phospho-tau missorting","description":"Transient Aβ exposure activates local kinase programs, especially CDK5/p25 and possibly GSK3β, that keep tau phosphorylated at missorting-associated epitopes. This would create a cell-autonomous phospho-tau maintenance state that survives Aβ withdrawal.","target_gene":"MAPT,CDK5,CAPN1,GSK3B","dimension_scores":{"evidence_strength":0.63,"novelty":0.54,"feasibility":0.82,"therapeutic_potential":0.52,"mechanistic_plausibility":0.72,"druggability":0.46,"safety_profile":0.35,"competitive_landscape":0.49,"data_availability":0.69,"reproducibility":0.64},"composite_score":0.59,"evidence_for":[{"claim":"CDK5 is a well-established driver of tau aggregation and can support a durable post-insult phosphorylation state.","pmid":"12765608"},{"claim":"Aβ-induced tau missorting is established, making kinase-locked persistence a plausible second step.","pmid":"20826658"}],"evidence_against":[{"claim":"Evidence for a specific dual GSK3β-CDK5 maintenance loop after Aβ withdrawal is weak; some acute systems emphasize CDK5 more than GSK3β.","pmid":"12765608"},{"claim":"Rescue by kinase inhibition may reflect generic stress suppression rather than reversal of a dedicated tau-maintenance circuit.","pmid":"20826658"}]},{"title":"Dendritic tau missorting persists through local proteostatic failure in endolysosomal and autophagy pathways","description":"Mislocalized tau impairs dendritic endosome-lysosome and autophagy flux, trapping tau species in the somatodendritic compartment and sustaining synaptotoxic signaling after Aβ has been removed. This is best viewed as a persistence amplifier rather than the leading initiating mechanism.","target_gene":"MAPT,RAB5,RAB7,LAMP1,TFEB","dimension_scores":{"evidence_strength":0.56,"novelty":0.57,"feasibility":0.68,"therapeutic_potential":0.47,"mechanistic_plausibility":0.67,"druggability":0.42,"safety_profile":0.44,"competitive_landscape":0.45,"data_availability":0.52,"reproducibility":0.55},"composite_score":0.53,"evidence_for":[{"claim":"Tau accumulation and neuritic proteostasis defects are common in AD-relevant systems, supporting a potential maintenance role.","pmid":"37812432"},{"claim":"Aβ-induced tau missorting provides a plausible upstream insult that could overload local clearance machinery.","pmid":"20826658"}],"evidence_against":[{"claim":"Direct evidence that transient Aβ exposure alone creates a durable dendrite-localized clearance defect sufficient to maintain missorting is limited.","pmid":"20826658"},{"claim":"Autophagy-enhancing interventions are highly nonspecific, so positive rescue would not uniquely validate this mechanism.","pmid":"37812432"}]},{"title":"Reactive astrocyte glutamate-handling failure sustains dendritic tau-associated excitotoxic stress after Aβ clearance","description":"Aβ leaves astrocytes in a reactive, low-EAAT2 state that increases extrasynaptic NMDA receptor drive, allowing dendritic tau to keep amplifying excitotoxic signaling without ongoing amyloid. This is a plausible circuit-level modifier mechanism but currently lacks direct evidence as the core persistence driver.","target_gene":"SLC1A2,GRIN2B,MAPT","dimension_scores":{"evidence_strength":0.47,"novelty":0.55,"feasibility":0.66,"therapeutic_potential":0.45,"mechanistic_plausibility":0.61,"druggability":0.43,"safety_profile":0.41,"competitive_landscape":0.46,"data_availability":0.41,"reproducibility":0.46},"composite_score":0.49,"evidence_for":[{"claim":"Tau-linked excitotoxic vulnerability and Aβ-induced synaptic dysfunction make a neuron-astrocyte persistence circuit plausible.","pmid":"20655099"},{"claim":"Aβ oligomers induce tau missorting and calcium dysregulation, compatible with a glutamate-clearance amplifier.","pmid":"20826658"}],"evidence_against":[{"claim":"Direct evidence for the sequence transient Aβ to lasting EAAT2 failure to persistent tau missorting is weak.","pmid":"24713000"},{"claim":"Replacing astrocytes after Aβ washout could plausibly leave neuronal tau pathology unchanged, arguing against astrocytes being required for persistence.","pmid":"20655099"}]},{"title":"BIN1-dependent trafficking defects determine whether post-Aβ tau missorting resolves or persists","description":"Aβ initially perturbs tau localization, but persistence depends on BIN1-regulated membrane and endocytic trafficking that prevents tau re-entry into the axon and stabilizes dendritic retention. This is a useful genetic-modifier hypothesis, but currently the least supported as a primary mechanism.","target_gene":"BIN1,MAPT","dimension_scores":{"evidence_strength":0.39,"novelty":0.63,"feasibility":0.64,"therapeutic_potential":0.34,"mechanistic_plausibility":0.5,"druggability":0.24,"safety_profile":0.52,"competitive_landscape":0.51,"data_availability":0.39,"reproducibility":0.4},"composite_score":0.46,"evidence_for":[{"claim":"BIN1 is a strong AD risk locus with links to tau biology and trafficking, supporting modifier-level relevance.","pmid":"29479533"}],"evidence_against":[{"claim":"The BIN1-tau relationship is complex and not straightforward, with sparse evidence that BIN1 controls post-Aβ persistence of missorting specifically.","pmid":"29479533"},{"claim":"Isoform- and cell-type-specific BIN1 biology makes simple causal interpretations in iPSC neurons uncertain.","pmid":"29479533"}]}],"knowledge_edges":[{"source":"Aβ oligomers","relation":"induces","target":"dendritic tau missorting","confidence":0.89,"pmid":"20826658"},{"source":"dendritic tau","relation":"enables","target":"FYN/NMDAR excitotoxic signaling","confidence":0.86,"pmid":"20655099"},{"source":"Aβ oligomers","relation":"promotes","target":"tau mislocalization to dendritic spines","confidence":0.84,"pmid":"24713000"},{"source":"CDK5","relation":"drives","target":"tau aggregation/phosphorylation","confidence":0.77,"pmid":"12765608"},{"source":"microglia/complement","relation":"mediates","target":"synapse loss in AD","confidence":0.85,"pmid":"29563239"},{"source":"microglia","relation":"drives","target":"tauopathy-linked neurodegeneration","confidence":0.82,"pmid":"31601677"},{"source":"tau oligomers","relation":"associated_with","target":"glia-mediated synapse elimination","confidence":0.72,"pmid":"37812432"},{"source":"tau oligomers","relation":"seed","target":"tau propagation","confidence":0.83,"pmid":"23882255"},{"source":"Aβ","relation":"can_seed","target":"tau propagation","confidence":0.7,"pmid":"26739002"},{"source":"BIN1","relation":"modulates","target":"tau pathology","confidence":0.52,"pmid":"29479533"}],"synthesis_summary":"The debate converges on a narrow conclusion: Aβ clearly induces dendritic tau missorting and synaptic injury, but true Aβ-independent persistence after complete amyloid removal remains unproven. The strongest surviving hypothesis is that transient Aβ exposure creates a transition into autonomous tau seeding, because tau propagation has the clearest mechanistic literature and the best therapeutic handles. A second strong survivor is that microglia and complement sustain downstream synapse loss after amyloid reduction, though this may maintain degeneration more directly than tau polarity failure itself. Fyn/NMDAR persistence and kinase-maintained phospho-tau remain plausible but are not yet cleanly demonstrated as post-clearance stable states.\n\nThe key experimental discriminator across all candidates is a rigorous pulse-washout design with orthogonal proof of near-zero residual Aβ, followed by delayed intervention. The most informative endpoint set should separate tau polarity, tau seeding activity, and ongoing degeneration rather than collapsing them into one phenotype. On current evidence, the field should prioritize endogenous-tau human neuron and tri-culture systems testing whether post-washout pathology is reversible by anti-seeding interventions, then by microglia/complement modulation, while treating proteostasis, astrocyte, and BIN1 models as secondary modifiers unless they show clear persistence after verified Aβ clearance."}