生物常量

Research reference only. BioConst updates and corrects content over time, but it cannot replace clinician-guided diagnosis, treatment, medication, or testing decisions.

Brain

Brain

Brain pages connect everyday questions about memory to biological variables, clinical boundaries, and source trails.

Medical Wiki

Memory and cognitive decline

Alzheimer disease and neurodegeneration

How Alzheimer disease disrupts memory networks, synapses, amyloid, tau, and brain volume over time.

Alzheimer diseaseAlzheimer disease: memory-network failureAlzheimer disease first disrupts memory-related networks such as the entorhinal cortex and hippocampus, then spreads across brain systems.
Hippocampus / entorhinal memory networkBeta-amyloidTauSynaptic plasticityBrain atrophy
Alzheimer disease: treatment boundariesAlzheimer disease: treatment boundariesCurrent anti-amyloid antibodies can slow progression in some early Alzheimer contexts, but they are not a promise to bring lost memory back.
Anti-amyloid antibodiesARIABeta-amyloidCognitive testing
synapse rebuildingCan synapses be rebuilt, and can neurons be backed up?If neurons and network scaffolding remain, some synaptic compensation may be possible; correctness can only be inferred, and neurons cannot be biologically backed up today.
Synapse lossSynaptic plasticityBrain atrophyHippocampus / entorhinal memory networkCognitive testingAlzheimer biomarkersSV2A PET / synaptic density imaging
Alzheimer root causeWhat is the root cause of Alzheimer disease?Synapse loss is close to the memory problem, but Alzheimer disease is not explained by one root cause.
Beta-amyloidTauSynapse lossSynaptic plasticityBrain atrophy
synapse rebuilding AlzheimerIf synaptic connections came back, would that treat Alzheimer disease?Rebuilding the right working memory-network connections would be a core treatment effect, but more synapses alone would not be enough.
Synapse lossSynaptic plasticityHippocampus / entorhinal memory networkBrain atrophyBeta-amyloidTau

Cognitive aging and decline

The boundary between slower recall, mild cognitive impairment, and dementia-level daily-life loss.

Age-related memory changeAge-related memory changeNormal aging can make learning and recall slower, but dramatic memory loss or getting lost is not just normal aging.
Episodic memoryCognitive testingActivities of daily livingHearing and vision input
MCIMild cognitive impairmentMCI means more memory or thinking problems than peers, while daily independence is mostly preserved.
MCICognitive testingActivities of daily livingEpisodic memory

Memory systems and forgetting

How experiences become memory, why recall fails, and why forgetting is not one single process.

How memory is stored and lostHow memory is stored and lostMemory is not a file in one place; it is built through brain networks, synaptic changes, consolidation, and later retrieval.
Episodic memoryHippocampus / entorhinal memory networkSynaptic plasticitySleep and memory

Modifiable context and treatment boundaries

Modifiable cognition context

Sleep, vascular risk, sensory input, mood, delirium, medicines, and other factors that can change cognition.

reversible memory loss factorsPotentially modifiable memory-loss factorsSome memory problems are shaped by sleep, blood pressure, sensory loss, depression, delirium, medicines, alcohol, smoking, and chronic disease context.
Sleep and memoryVascular risk and brain healthHearing and vision inputDepression, delirium, and medication contextCognitive testing