Myelin from human peripheral nerves. Quantitative and qualitative studies in two age groups
The Journal of Clinical Investigation
|February 1, 1973
Summary
Aging significantly reduces myelin content in peripheral nerves, a key component for nerve function. This study quantifies myelin loss in older adults, correlating it with age-related nerve dysfunction.
Area of Science:
- Neuroscience
- Gerontology
- Biochemistry
Background:
- Myelin is crucial for peripheral nerve function, enabling rapid signal transmission.
- Age-related changes in nerve structure and function are well-documented, but direct quantification of myelin loss is less understood.
Purpose of the Study:
- To quantitatively assess myelin content in femoral nerve segments from different age groups.
- To investigate potential age-related changes in myelin composition.
Main Methods:
- Myelin isolation from autopsy-obtained femoral nerve segments using flotation procedures.
- Quantitative analysis of myelin components (cholesterol, glycolipid, phospholipid, protein).
- Comparison of myelin content between younger (35-58 yr) and older (60-77 yr) adult groups.
Main Results:
- Significantly lower myelin content (2.6 mg/g) in older adults compared to younger adults (10.8 mg/g).
- Myelin decrease in older adults is absolute, not relative to nerve size or non-myelin content.
- Higher protein percentage in myelin from older adults, with no qualitative lipid differences.
Conclusions:
- Direct measurement reveals a substantial age-related decline in peripheral nerve myelin.
- This myelin reduction may underlie age-associated deficits in nerve conduction velocity and vibratory sensation.
