English:Aging – Microglia between proteostatic support and synapse loss
aiMOOCAging – Microglia between proteostatic support and synapse loss
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Introduction
Aging – Microglia between proteostatic support and synapse loss is an expert-level colloquium on how to reason from protein-transfer data to causal models of brain aging. The central source is the 2026 Nature study by Guldner and colleagues, which used cell-specific bioorthogonal non-canonical amino-acid tagging (BONCAT) to follow neuronal proteins across age. The study reported that neuronal protein degradation slows with age, that many neuronal proteins enter an aged neuronal aggregome, and that neuron-derived proteins—especially synaptic proteins—accumulate in microglia. Importantly, accumulation in microglia is an observation about location and transfer; it is not by itself evidence that uptake benefits neurons, harms synapses, or causes age-related dysfunction.
In this course, you will treat three explanations as genuine competitors: beneficial disposal, harmful synaptic uptake, and shared upstream injury. Your task is not to defend one model rhetorically. Your task is to design experiments in which the models make different preregistered predictions about protein movement, neuronal proteostasis, microglial handling, synapse number, and—most importantly—synaptic function.
The video provides broader context on mechanisms of brain aging. It is background material rather than direct evidence for any of the three competing models.
Learning Goals
By the end of this colloquium, you should be able to distinguish observation from causal interpretation in neuron–microglia transfer experiments; derive mutually competing mechanistic models from the same dataset; design cell-specific and temporally separated perturbations; trace neuron-derived proteins without confusing presence in microglia with benefit; select synaptic physiology as a decisive endpoint; detect dissociation-induced uptake and adherent debris; distinguish scavenging of material already lost from culling of still-functional synapses; preregister model-specific predictions before seeing results; and update causal beliefs when different readouts disagree.
Core Evidence from Guldner et al. 2026
What the study directly supports
Guldner and colleagues developed mouse models in which mutant aminoacyl-tRNA synthetases permit cell-selective incorporation of azide-bearing amino acids into newly synthesized proteins. The strongest neuronal labeling was obtained with a CAMK2A-linked PheRS* system using azido-phenylalanine. The labeled proteins could then be enriched and quantified by liquid chromatography–mass spectrometry. This strategy allowed the authors to follow neuronal proteome turnover in vivo across age.
The study found that neuronal protein half-life increased substantially with age and that degradation changes were regionally heterogeneous. It also defined an aged neuronal aggregome containing many proteins with reduced degradation. In the neuron-to-microglia analysis, neuronal proteins were labeled in young and aged mice and viable CD11b-positive cells were isolated by fluorescence-activated cell sorting. The isolation included an engulfment-inhibitor cocktail intended to reduce artificial ex vivo uptake. Synaptic proteins were strongly represented among the neuron-derived proteins detected in microglia, and many of the proteins enriched in aged microglia also showed slowed degradation and/or aggregation with age.
These observations support the claims that neuronal proteostasis changes with age and that labeled neuron-derived proteins can be recovered from microglia. They also justify asking how such transfer occurs and what it does. They do not establish whether transfer is protective, destructive, compensatory, epiphenomenal, or a mixture that changes over time.
The inferential gap
The key logical distinction is:
Microglial uptake or accumulation = neuron-derived material is detected in or associated with microglia.
Proteostatic benefit = neurons retain better protein quality, lower toxic burden, or improved function because microglia take up that material.
Synaptic harm = microglial action causes loss or weakening of functional synapses.
These are different propositions. A single increase in neuron-derived synaptic protein inside microglia can be consistent with all three. Therefore, the course treats microglial accumulation as an intermediate measurement, not a verdict.
Three Competing Causal Models
Model A: Beneficial Disposal
In the beneficial disposal model, aging impairs neuronal protein turnover, producing slow-degrading or aggregated proteins. Neurons transfer some of this burden to microglia by release, shedding, vesicular export, nanotube-like transfer, or selective removal of already-compromised synaptic material. Microglial uptake reduces the proteostatic burden remaining in neurons.
The crucial causal prediction is not merely that labeled neuronal protein appears in microglia. It is that preventing microglial acquisition or processing should increase neuronal burden and worsen neuronal or synaptic function, whereas improving microglial processing should reduce neuronal burden or preserve function. A finding of microglial uptake without such downstream benefit is insufficient.
Model B: Harmful Synaptic Uptake
In the harmful synaptic uptake model, microglia actively remove synaptic material that is still functionally valuable, or they escalate removal beyond what is necessary for debris clearance. Uptake therefore contributes causally to synapse loss or weakening.
The decisive prediction is that a microglia-specific reduction in the relevant recognition or engulfment pathway should preserve synaptic function and/or synapse structure, even when neuronal proteostatic stress remains. If uptake falls but synaptic function does not improve, evidence for this model weakens. Conversely, preserved long-term potentiation, miniature synaptic event frequency, or other prespecified physiological measures after selective uptake blockade would support a causal contribution of microglial removal.
Model C: Shared Upstream Injury
In the shared upstream injury model, neuronal proteostatic failure is the common cause of two downstream phenomena: synaptic dysfunction/loss and increased release or exposure of neuronal proteins that microglia then scavenge. Microglial accumulation correlates with synapse loss because both are responses to the same upstream injury.
Here, blocking microglial uptake should reduce the microglial label signal but should not rescue the primary synaptic functional decline. In contrast, a neuron-specific intervention that improves proteostasis should reduce both synaptic dysfunction and microglial accumulation. This is the classic pattern expected for a common cause.
Why Synaptic Function Must Be an Endpoint
A synaptic protein inside a microglial lysosome does not tell you whether the original synapse was silent, damaged, doomed, or fully functional. Likewise, a reduced count of a synaptic marker does not necessarily reveal how network communication changed.
Therefore, a causal study should prespecify at least one physiological primary endpoint. Suitable examples include hippocampal CA1 long-term potentiation, input–output curves, paired-pulse ratio, miniature excitatory postsynaptic current frequency and amplitude, miniature inhibitory postsynaptic currents, or network activity measured with multielectrode arrays. Structural endpoints such as spine density, synaptophysin puncta, PSD95 puncta, or electron-microscopic synapse counts are valuable secondary endpoints, but they should not replace function.
For an expert colloquium, choose one brain region and one primary physiological endpoint before data collection. For example, you might preregister CA1 long-term potentiation as the primary endpoint and use microglial neuronal-protein burden, neuronal insoluble protein burden, spine density, and lysosomal localization as secondary endpoints.
Experimental Architecture
Factor 1: Neuron-specific proteostasis perturbation
Use an adult-onset neuron-restricted manipulation that either worsens or improves proteostasis. The manipulation should be inducible so that it does not alter circuit development. Depending on the exact question, suitable strategies include neuron-restricted modulation of autophagic flux, proteasomal capacity, molecular chaperone activity, or a defined aggregation-prone cargo. The experimental claim should be narrow: the manipulation changes a prespecified proteostasis axis in neurons.
Verify target engagement inside neurons with an independent assay. Do not infer neuronal rescue merely from reduced microglial labeling, because reduced microglial signal could reflect impaired transfer rather than improved neuronal proteostasis.
Factor 2: Microglia-specific uptake perturbation
Use an adult-onset microglia-restricted perturbation of a candidate recognition or engulfment pathway. Inducible microglial drivers such as validated Tmem119- or Sall1-based systems may be preferable to developmental knockouts when the goal is to avoid circuit-development effects. If a CX3CR1-based system is used, build in an appropriate washout interval and verify that the manipulation is restricted as intended.
The first experiment should avoid indiscriminate microglial depletion because depletion changes surveillance, trophic support, cytokine signaling, debris clearance, and cell density simultaneously. A receptor- or pathway-specific perturbation creates a cleaner test of whether neuronal-protein acquisition itself contributes to synaptic outcome.
Candidate pathways may include complement-dependent recognition, TAM-family receptors, phosphatidylserine recognition pathways, or other mechanisms nominated by spatial and proteomic data. The exact target should be selected before outcome data are examined.
Factor 3: Temporal separation
Separate protein labeling, perturbation, and outcome measurement in time. This prevents an intervention from being mistaken for a change in protein synthesis or label incorporation.
A useful design is a pulse–chase framework:
- Establish adult cell-specific genetic states and verify specificity before the labeling pulse.
- Pulse-label CAMK2A-positive neuronal proteins with the bioorthogonal amino acid for a prespecified interval.
- Begin the chase so that no new labeled protein is intentionally added.
- Apply or activate the temporally defined microglial uptake perturbation during the transfer window, or use a parallel cohort in which a neuron-specific rescue is activated after the pulse.
- Sample early, intermediate, and late time points for neuronal burden, microglial burden, localization, and synaptic physiology.
This design asks whether already-labeled neuronal proteins move differently after the perturbation. It is stronger than comparing two groups in which labeling, synthesis, injury, and uptake all change simultaneously.
Protein tracing
Use neuron-specific BONCAT or an equivalent orthogonal tagging strategy to establish the neuronal origin of the protein pool. For each protein-tracing experiment, record the label source, pulse length, chase length, brain region, cellular isolation method, number of pooled brains, mass-spectrometry normalization method, and criteria for calling a protein transferred.
A strong tracing pipeline combines:
- Neuron-specific labeling of newly synthesized protein.
- Quantification of labeled protein remaining in neurons during the chase.
- Quantification of labeled protein recovered from microglia.
- Spatial confirmation that candidate proteins are intracellular in microglia rather than attached to the surface.
- Lysosomal or phagolysosomal colocalization for at least a subset of candidates.
- A functional synaptic endpoint measured in an adjacent or matched preparation.
The transfer readout should be expressed both as absolute burden and, where possible, relative to the labeled neuronal source pool. Otherwise, an apparent increase in microglial signal could simply arise because the upstream neuronal labeled pool is larger.
The Dissociation and Debris Audit
A major alternative explanation is that some apparent uptake occurs during tissue processing or reflects neuronal debris stuck to the outside of microglia. Guldner et al. explicitly used an engulfment-inhibitor cocktail during isolation, which is an important control. However, no single inhibitor control eliminates every processing artifact.
A particularly relevant methodological study is the FEAST toolkit, which showed that tissue dissociation can create false-positive synaptic protein signals in microglia and introduced “sniffer cell” controls to detect ex vivo contamination.
FEAST: a flow cytometry-based toolkit for interrogating microglial engulfment
Preregistered artifact controls
Dissociation-mixing control: Mix tissue from a labeled brain with tissue containing distinguishable microglia that could not have encountered the label in vivo. If these “sniffer” microglia acquire the neuronal label only after the tissues are combined, the signal estimates ex vivo contamination.
Processing-time series: Compare short and long dissociation intervals. A signal that rises with processing duration is suspicious for ex vivo acquisition.
Engulfment-inhibitor condition: Include the same uptake-inhibitor strategy across all biological groups and report whether age changes inhibitor sensitivity.
Surface-versus-internal discrimination: Use an extracellular quenching step, membrane-impermeant labeling, protease stripping when compatible, or high-resolution optical sectioning to distinguish adherent material from intracellular material.
In situ orthogonal validation: Quantify candidate neuronal proteins within three-dimensional microglial volumes in fixed tissue that was never dissociated. Add lysosomal markers and blinded segmentation. Correlative light-electron microscopy or immuno-electron microscopy can provide stronger localization for selected candidates.
Debris burden control: Quantify free synaptic debris in the preparation. If aged tissue creates more debris during homogenization, microglia from aged samples may appear more positive even without greater in vivo uptake.
Protocol comparison: Compare at least two isolation methods in a validation cohort. Do not assume that “cold” processing automatically prevents contamination; empirical testing is required.
Cell identity control: Confirm microglial identity and exclude border-associated macrophages and infiltrating myeloid cells as far as the experimental system permits.
Culling, Scavenging, and Transfer Without Engulfment
There are at least three physically distinct routes to a microglial neuron-derived protein signal.
Culling means microglia participate in removing a still-attached synaptic element. If this process is excessive, it can be directly synaptotoxic.
Scavenging means the neuron has already shed or lost the material and microglia clear the resulting debris. In this case, uptake can correlate with synapse loss without causing it.
Transfer without whole-synapse engulfment can occur through extracellular vesicles, secreted proteins, membrane fragments, or other intercellular transfer routes. Such transfer may be proteostatic, neutral, or harmful depending on cargo and context.
The experimental design must therefore localize the cargo and establish temporal order. Detecting presynaptic and postsynaptic proteins in microglia is not by itself proof that an intact synapse was eaten.
Preregistered Prediction Matrix
Before collecting outcome data, register the direction of every prediction. Use one primary functional endpoint and define what would count as support, contradiction, or ambiguity.
| Test or observation | Model A: Beneficial disposal | Model B: Harmful synaptic uptake | Model C: Shared upstream injury |
|---|---|---|---|
| Microglia-specific uptake blockade lowers neuron-derived protein in microglia | Expected | Expected | Expected |
| Uptake blockade increases neuronal insoluble or slow-degrading labeled protein | Expected if transfer is an effective disposal route | Not required; may be unchanged or rise modestly | Not required for the primary mechanism |
| Uptake blockade rescues prespecified synaptic physiology | Not expected; function may worsen if disposal is protective | Expected | Not expected |
| Uptake blockade preserves structural synapse number | Not necessarily; may reduce clearance but increase dysfunctional remnants | Expected if microglial removal is causal | Little primary rescue expected |
| Neuron-specific proteostasis rescue reduces microglial neuronal-protein burden | Expected because less cargo requires disposal | Possible if stress marks synapses for uptake | Expected because the shared upstream driver is reduced |
| Neuron-specific proteostasis rescue improves synaptic physiology | Expected | Expected if neuronal stress drives microglial targeting | Expected |
| Microglial uptake rises before measurable synaptic dysfunction | Compatible but not sufficient | Supports a causal uptake sequence if blockade also rescues function | Less expected; common injury may precede both |
| Synaptic dysfunction precedes most microglial uptake | Compatible with cleanup of failed synapses | Weakens simple harmful-uptake-first model | Supports upstream injury followed by scavenging |
| In situ intracellular cargo is confirmed but dissociation signal is larger | Biological uptake plus processing inflation | Biological uptake plus processing inflation | Biological uptake or scavenging plus processing inflation |
| Sniffer cells acquire label during dissociation | Reveals artifact; does not distinguish causal models | Reveals artifact; does not distinguish causal models | Reveals artifact; does not distinguish causal models |
| Enhancing microglial lysosomal processing lowers retained cargo but preserves or improves synaptic physiology | Supports efficient beneficial disposal | Weakens a simple retained-cargo-equals-harm interpretation | Could be neutral unless upstream neuronal injury changes |
Preregistration rule: do not rewrite the prediction matrix after seeing the data. If an outcome is compatible with more than one model, mark it as non-discriminating rather than forcing a conclusion.
A Minimal Factorial Experiment
A high-information experiment can use a two-by-two design in aged mice:
| Group | Neuronal proteostasis state | Microglial uptake state | Purpose |
|---|---|---|---|
| Control | Baseline aged state | Baseline | Defines the aged reference |
| Neuronal rescue | Improved proteostasis | Baseline | Tests whether the upstream neuronal state drives both transfer and dysfunction |
| Uptake blockade | Baseline aged state | Reduced | Tests whether microglial acquisition causally changes synaptic function |
| Combined | Improved proteostasis | Reduced | Tests additivity, interaction, and pathway ordering |
Add young reference animals for calibration, but do not use young-versus-aged differences as a substitute for causal perturbation. The critical inference comes from intervention within the aged state.
Prespecify a primary physiological endpoint, a primary protein-transfer endpoint, and one neuronal proteostasis endpoint. For example:
- Primary function: CA1 long-term potentiation magnitude at a fixed post-tetanus interval.
- Primary transfer: neuron-derived BONCAT signal per purified microglial cell or per defined microglial protein mass.
- Primary neuronal proteostasis: labeled insoluble protein burden in hippocampal neurons.
Other readouts should be labeled secondary or exploratory.
Statistical and Reproducibility Logic
The experimental unit must match the intervention. If several brains are pooled to obtain sufficient microglia for proteomics, the pool—not each cell or peptide—is the biological replicate. Electrophysiological slices from one animal are nested within that animal and should not be treated as independent mice.
Preregister exclusion criteria, sex balance or sex-stratified analysis, age windows, region, sample-size rationale, randomization, blinding, batch structure, and the order in which tissue is processed. If proteomic abundance is normalized, specify the normalization before group labels are unblinded. For longitudinal or multi-time-point designs, distinguish repeated measures from cross-sectional samples.
A model-comparison analysis can be stronger than a list of separate significance tests. You can estimate direct effects of microglial uptake perturbation on synaptic physiology, effects on neuronal burden, and interactions with neuronal proteostasis rescue. The purpose is not to obtain one significant P value; it is to decide which predicted pattern best matches the joint data.
Interpretation Rules
Rule 1: Uptake is not synonymous with benefit. Benefit requires evidence that uptake improves a neuronal or circuit outcome relative to a condition in which uptake is selectively reduced.
Rule 2: Uptake is not synonymous with synapse destruction. Harm requires evidence that selective reduction of uptake preserves a functional or structural synaptic endpoint.
Rule 3: Colocalization is not equivalent to internalization. Use three-dimensional localization and an internal compartment marker.
Rule 4: Internalization is not equivalent to whole-synapse culling. The cargo may be vesicular, shed, fragmented, or already destined for clearance.
Rule 5: Correlation across age is not temporal precedence. Use pulse–chase and early sampling.
Rule 6: A negative rescue can be informative. If uptake blockade changes the transfer readout but not synaptic physiology, the harmful-uptake model loses support even though the perturbation “worked.”
Rule 7: Mixed mechanisms are possible, but invoke them only after the preregistered simple models have been tested. A result in which early clearance helps neurons but chronic cargo retention impairs microglia should emerge from the data rather than being used to immunize a favored model against falsification.
Interactive Tasks
Quiz: Test Your Knowledge
Which observation from Guldner et al. most directly motivates a neuron-to-microglia transfer hypothesis? (Neuron-derived labeled proteins are detected in microglia) (!Microglia are the only glial cells in the brain) (!All aged synapses are electrically silent) (!Every aggregated protein is extracellular)
What would most strongly support the beneficial disposal model? (Uptake blockade increases neuronal protein burden and worsens synaptic function) (!Uptake blockade reduces microglial label without changing anything else) (!Microglia contain a synaptic marker after dissociation) (!Aged mice have fewer synapses than young mice)
What is the decisive prediction of the harmful synaptic uptake model? (Selective uptake blockade preserves synaptic function) (!All microglia disappear after the intervention) (!Neuronal protein synthesis stops completely) (!Every synaptic protein becomes insoluble)
What pattern best fits a shared upstream injury model? (Neuronal rescue improves function and lowers uptake while uptake blockade alone does not rescue function) (!Uptake blockade rescues function despite unchanged neuronal injury) (!Microglial label rises only during tissue dissociation) (!Young animals express more synaptic proteins than aged animals)
Why should synaptic physiology be preregistered as an endpoint? (It tests whether structural or uptake changes alter communication) (!It proves every engulfed protein came from one intact synapse) (!It eliminates the need for protein tracing) (!It prevents any age-related variability)
What is the purpose of a sniffer-cell mixing control? (To detect ex vivo acquisition of neuronal material during processing) (!To increase neuronal protein aggregation) (!To measure behavioral memory directly) (!To replace all in situ imaging)
Why is temporal separation of labeling and perturbation useful? (It helps distinguish altered transfer from altered protein synthesis) (!It guarantees that microglia never contact synapses) (!It makes all proteins degrade at the same rate) (!It removes the need for a chase period)
Which result would weaken a simple harmful-uptake model? (Uptake blockade reduces microglial cargo but does not rescue synaptic function) (!Uptake blockade preserves long-term potentiation) (!Microglial cargo rises before functional decline) (!Synaptic markers are found inside microglial lysosomes)
What does three-dimensional intracellular localization add to a transfer study? (It distinguishes internal cargo from surface-associated debris more effectively) (!It proves that cargo removal benefits neurons) (!It determines the complete protein half-life by itself) (!It replaces cell-specific genetic labeling)
What is the safest interpretation of increased neuron-derived protein in aged microglia? (It is evidence of increased accumulation that still requires causal testing) (!It proves microglia protect every aged neuron) (!It proves microglia destroy every aged synapse) (!It proves tissue dissociation has no effect)
Memory Game
| Beneficial disposal | Microglial handling causally reduces neuronal proteostatic burden |
| Harmful uptake | Microglial removal causally contributes to synaptic dysfunction or loss |
| Shared injury | A common neuronal insult drives both dysfunction and microglial cargo |
| Pulse chase | Labeling strategy that separates protein birth from later fate |
| Sniffer cell | Control cell that reveals ex vivo acquisition during processing |
| Proteostasis | Maintenance of protein synthesis folding trafficking and degradation |
Drag and Drop
| Match the correct terms. | Topic |
|---|---|
| Beneficial disposal | Uptake blockade worsens neuronal burden and function |
| Harmful synaptic uptake | Uptake blockade preserves synaptic physiology |
| Shared upstream injury | Neuronal rescue improves both function and transfer signal |
| Sniffer-cell control | Detects processing-induced acquisition |
| Pulse–chase tracing | Separates protein synthesis from later transfer |
...
Crossword Puzzle
| Microglia | Which resident immune cells of the brain are central to this course? |
| Proteostasis | What term describes maintenance of protein homeostasis? |
| Synapse | What neuronal junction is the functional endpoint of interest? |
| Engulfment | What process describes cellular uptake of extracellular material? |
| Aggregome | What term describes the collection of proteins found in aggregates? |
| Dissociation | What tissue-processing step can create artifactual uptake or debris adherence? |
LearningApps
Cloze Text
Open-Ended Tasks
Easy
- Causal diagram: Draw the three models as directed acyclic graphs and mark which arrows are directly observed versus hypothesized.
- Endpoint audit: Take five common readouts in microglia–synapse studies and classify each as uptake, structure, proteostasis, or function.
- Artifact map: Create a one-page diagram showing where dissociation, debris adhesion, ex vivo engulfment, sorting, and normalization can bias a transfer measurement.
- Figure critique: Select one figure from Guldner et al. 2026 and write a short caption that separates the measured result from the causal interpretation.
Standard
- Pulse–chase protocol: Draft a temporally separated labeling and chase schedule with an adult neuron-specific proteostasis intervention and a microglia-specific uptake intervention.
- Sniffer-cell experiment: Design a tissue-mixing control that can estimate ex vivo acquisition during dissociation and specify the expected positive and negative controls.
- Synaptic physiology plan: Choose one brain region and one primary electrophysiological endpoint and justify why it discriminates among the three models.
- Spatial validation: Design an imaging workflow that tests whether a neuron-derived synaptic protein is inside a microglial lysosome rather than attached to the microglial surface.
Advanced
- Factorial perturbation study: Build a two-by-two aged-mouse experiment crossing neuron-specific proteostasis rescue with microglia-specific uptake blockade and state the interaction predicted by each model.
- Pre-registration: Write a preregistration containing primary outcomes, exclusion rules, randomization, blinding, sample-size logic, nested-data structure, and the full prediction matrix before simulated data are revealed.
- Protein tracing analysis: Propose a quantitative model that relates labeled neuronal source pool, microglial cargo, degradation, and sampling time, and show how a larger source pool could mimic increased transfer.
- Colloquium defense: Record a ten-minute video in which you defend the experiment against three alternatives: ex vivo uptake, scavenging of already-lost synapses, and a shared upstream neuronal injury.
Learning Assessment
- Causal discrimination: Given a dataset in which uptake blockade lowers microglial cargo but leaves long-term potentiation unchanged, explain how the evidence updates each of the three models without declaring uptake beneficial or harmful by definition.
- Temporal inference: Interpret a time course in which neuronal aggregation rises first, synaptic physiology falls second, and microglial cargo rises third, then propose one follow-up experiment that could distinguish scavenging from culling.
- Artifact correction: Given sniffer-cell contamination of ten percent in young tissue and thirty percent in aged tissue, explain why a raw age difference in microglial cargo is biased and propose a prespecified correction or exclusion strategy.
- Mechanism transfer: Apply the three-model framework to a different neurodegenerative context and identify which measurements would remain valid and which would need disease-specific modification.
- Integrated study design: Produce a complete causal experiment with cell-specific perturbations, neuron-origin protein tracing, in situ validation, dissociation controls, and a primary synaptic physiology endpoint.
- Model revision: Explain how you would revise the causal model if early uptake improves neuronal proteostasis but prolonged microglial cargo accumulation later impairs synaptic function.
Evidence of Learning
Strong evidence of learning includes the ability to distinguish transfer from benefit, correlation from causation, and structural loss from functional impairment; a correctly specified three-model causal diagram; a preregistered prediction matrix that contains genuinely discriminating outcomes; a cell-specific and adult-onset perturbation strategy; a temporally separated pulse–chase design; quantitative protein tracing that accounts for the neuronal source pool; a validated sniffer-cell or equivalent dissociation-artifact control; orthogonal in situ evidence for intracellular localization; an electrophysiological primary endpoint; correct treatment of pooled and nested biological replicates; and a written interpretation that allows a favored model to fail.
Key Sources and Further Reading
The primary study for this course is Guldner et al. 2026, Nature. Its core contribution is the cell-specific study of neuronal protein turnover, aggregation, and neuron-to-microglia protein accumulation during aging.
For experimental controls on synaptic-material uptake, use FEAST, Nature Communications 2023, especially the dissociation and “sniffer-cell” logic.
For broader context on microglial aging and synaptic phagocytosis, consult the open literature on Microglia, Neuroinflammation, Synaptic pruning, Complement system, Autophagy, Proteasome, and Protein aggregation.
OERs on the Topic
Linked Learning Areas
The topic connects molecular neuroscience, cell biology, immunology, aging biology, neurodegeneration, proteomics, microscopy, electrophysiology, statistics, and causal inference. At university level it is suitable for advanced courses in neuroscience, molecular medicine, neuroimmunology, biochemistry, systems biology, and biomedical research methods.