Synaptic Dysfunction in Corticobasal Syndrome represents a fundamental pathophysiology driving both cognitive and motor deficits in CBS. Synaptic loss is the strongest pathological correlate of cognitive impairment in neurodegenerative diseases, and in CBS, synaptic dysfunction occurs early and progresses rapidly. This page covers the mechanisms, biomarkers, clinical correlations, and therapeutic implications of synaptic dysfunction in CBS.
Pathway / Mechanism Diagram
graph TD
A["Abeta Oligomers / Tau / alpha-Synuclein"] --> B["Postsynaptic Receptor Disruption"]
A --> C["Presynaptic Vesicle Dysfunction"]
B --> D["NMDAR Internalization"]
B --> E["AMPAR Removal"]
D --> F["Impaired LTP"]
E --> F
C --> G["Reduced Neurotransmitter Release"]
G --> F
F --> H["Dendritic Spine Loss"]
A --> I["Complement-Mediated Synapse Elimination"]
I --> J["Microglial Synapse Phagocytosis"]
J --> H
H --> K["Circuit Disconnection"]
K --> L["Cognitive Decline"]
style A fill:#ef5350,color:#e0e0e0
style H fill:#5d4400,color:#e0e0e0
style L fill:#ef5350,color:#e0e0e0
1. Synaptic Pathology in CBS
1.1 Pathological Findings
Postmortem studies reveal significant synaptic loss in CBS[^1]:
...
Synaptic Dysfunction in Corticobasal Syndrome
Overview
Synaptic Dysfunction in Corticobasal Syndrome represents a fundamental pathophysiology driving both cognitive and motor deficits in CBS. Synaptic loss is the strongest pathological correlate of cognitive impairment in neurodegenerative diseases, and in CBS, synaptic dysfunction occurs early and progresses rapidly. This page covers the mechanisms, biomarkers, clinical correlations, and therapeutic implications of synaptic dysfunction in CBS.
Pathway / Mechanism Diagram
Mermaid diagram (expand to render)
1. Synaptic Pathology in CBS
1.1 Pathological Findings
Postmortem studies reveal significant synaptic loss in CBS[^1]:
Prefrontal cortex: 40-60% reduction in synaptic density
Motor cortex: 30-50% reduction correlating with cortical signs
Basal ganglia: Variable loss depending on regional involvement
Hippocampal involvement: Variable depending on comorbid AD pathology
Synaptic Markers
Synaptophysin: Decreased in 70-80% of CBS cases
Synapsin I: Reduced in cortical regions
PSD-95: Loss of postsynaptic density
SV2A: Reduced synaptic vesicle protein
1.2 Tau-Mediated Synaptic Toxicity
Tau pathology directly disrupts synaptic function:
Pre-synaptic Effects
Tau accumulation in presynaptic terminals: Impairs vesicle release