Dopamine transporter availability in clinically normal aging is associated with individual differences in white...

Area of Science:

• Neuroimaging
• Gerontology
• Neuroscience

Background:

• Aging affects white matter integrity, amyloid plaque presence, and dopamine function biomarkers.
• In vivo human imaging can detect and quantify these age-related brain changes.

Purpose of the Study:

• To determine if imaging-based markers of aging in the brain are independent.
• To test the hypothesis of multiple independent neurobiological cascades in the aging brain.

Main Methods:

• Assessed MRI markers of white matter integrity in 53 healthy older adults (65-87 years).
• Used PET imaging for dopamine transporter density and amyloid deposition in the same individuals.
• Employed multiple regression analysis to examine relationships between imaging markers.

Main Results:

• Dopamine transporter availability was predicted by white matter integrity, independent of chronological age.
• Dopamine transporter availability correlated with systolic blood pressure, aligning with cardiovascular health links.
• No association was found between dopamine transporter availability and amyloid burden.

Conclusions:

• Neurobiological correlates of dopamine transporter measures in aging are linked to white matter integrity and cardiovascular risk, not Alzheimer's disease.
• Common imaging markers of the aging brain, often studied separately, may reflect interconnected neurobiological processes.