The Relationship Between the Striatal Dopaminergic Neuronal and Cognitive Function With Aging

Area of Science:

• Neuroscience
• Gerontology
• Radiology

Background:

• Cognitive function and striatal dopamine transporter (DAT) function naturally decline with age.
• The precise relationship between age-related changes in DAT binding and cognitive performance remains unclear.

Purpose of the Study:

• To investigate the association between age-related alterations in striatal DAT binding and cognitive function in healthy individuals.

Main Methods:

• 30 healthy volunteers (41-82 years) underwent MRI and 123I-FP-CIT SPECT scans.
• Cognitive function was assessed using the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III).
• Striatal DAT binding (striatal occipital ratio - SOR) and cognitive subscores were analyzed using multiple regression and path analyses.

Main Results:

• Full IQ, verbal IQ, and verbal comprehension positively correlated with age-adjusted striatal DAT binding (P < 0.01).
• Coding digit symbol correlated with most striatal regions (P < 0.04), while picture completion and similarities showed specific correlations with the right and left caudate, respectively.
• Path analysis indicated that the right caudate-picture completion and left caudate-similarities associations were independent of age.

Conclusions:

• Individual differences in age-related striatal DAT binding are associated with verbal cognitive function.
• The caudate nucleus is significantly involved in the relationship between striatal DAT binding and cognitive performance in aging.