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Olfactory Assays for Mouse Models of Neurodegenerative Disease
Published on: August 25, 2014
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Olfactory bulb involvement in neurodegenerative diseases.
Johannes Attems1, Lauren Walker, Kurt A Jellinger
1Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK.
Acta Neuropathologica
|February 21, 2014
Summary
Olfactory dysfunction is an early sign of neurodegenerative diseases like Alzheimer's and Parkinson's. Olfactory bulb pathology correlates with disease severity, suggesting potential for early diagnosis via olfactory biopsies.
Area of Science:
- Neuroscience
- Neuropathology
- Biomarker Research
Background:
- Olfactory dysfunction is a common early symptom in neurodegenerative diseases such as Alzheimer's disease (AD) and synucleinopathies.
- Neuropathological changes in the olfactory system, including the olfactory epithelium and bulb, are linked to protein deposition (α-synuclein, tau, neurofilament).
- These changes trigger molecular cascades like oxidative damage and neuroinflammation, contributing to neuronal cell death.
Purpose of the Study:
- To summarize current knowledge on olfactory system neuropathology in AD and synucleinopathies.
- To present findings on olfactory bulb and tract pathology in a large autopsy cohort.
- To explore the potential of olfactory biopsies as an early diagnostic biomarker for neurodegenerative diseases.
Main Methods:
- Review of current literature on olfactory dysfunction in neurodegenerative diseases.
- Analysis of neuropathological findings in the olfactory bulb and tract from an autopsy cohort (n=536).
- Correlation analysis between olfactory pathology (HPτ, Aβ, αSyn) and established neuropathological staging systems (Braak, Thal, Lewy body pathology).
Main Results:
- Severity of olfactory bulb pathology (HPτ, Aβ, αSyn) significantly correlated with increasing neuritic Braak stages, Thal Aβ phases, and cerebral Lewy body pathology (P < 0.001).
- Pathological protein deposition in the olfactory system is a feature of synucleinopathies and AD.
- Damage to neurotransmitter systems (cholinergic, serotonergic, noradrenergic) is associated with severe olfactory loss.
Conclusions:
- Olfactory bulb pathology is closely linked to the severity and staging of major neurodegenerative diseases.
- Olfactory biopsies, potentially from the olfactory epithelium, warrant further investigation as a tool for early diagnosis and stratification in neurodegenerative disease clinical trials.
- Identifying preclinical neurodegeneration and stratifying patients based on underlying pathology may be facilitated by olfactory assessments.
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