Associations between inflammation and striatal dopamine D2-receptor availability in aging.

Area of Science:

• Neuroscience
• Aging Research
• Dopamine System

Background:

• Normal brain aging involves dopamine decline, potentially contributing to cognitive deficits.
• Individual differences in dopamine integrity in older adults are not well understood.
• Investigating inflammation's role in dopamine D2-receptor (DRD2) availability is crucial for understanding aging brains.

Purpose of the Study:

• To examine the association between inflammation and dopamine D2-receptor (DRD2) availability and its 5-year change.
• To determine if sex influences the relationship between inflammation and DRD2 availability.
• To assess if inflammation and white-matter lesions independently predict DRD2 availability.

Main Methods:

• Healthy adults over 60 years old were assessed twice over 5 years.
• Dopamine D2-receptor (DRD2) availability was measured using 11C-raclopride PET scans.
• Inflammation was assessed via C-reactive protein-associated DNA methylation scores; white-matter lesions by MRI.

Main Results:

• Higher inflammation markers (DNA methylation scores) correlated with reduced striatal DRD2 availability.
• This association was significant in men but not in women, indicating a sex-specific effect.
• Inflammation and white-matter lesions independently predicted lower DRD2 availability in men.

Conclusions:

• Inflammation, indicated by DNA methylation scores, is associated with reduced dopamine D2-receptor (DRD2) availability in older men.
• These findings highlight a sex-specific inflammatory impact on dopamine integrity in aging.
• Further research on various inflammatory markers and dopamine system interactions is warranted.