Effects of age on dopamine D2 receptor availability in striatal subdivisions: a high-resolution positron emission tomography study.

The purpose of the present study was to examine the relationship between age and dopamine D(2) receptor availability in striatal subdivisions of young and middle-aged healthy subjects using high-resolution positron emission tomography (PET) with [(11)C]raclopride to better characterize the nature of age-related decrements in striatal D(2) receptor availability. Twenty-four healthy volunteers completed 3-Tesla magnetic resonance imaging and high-resolution [(11)C]raclopride PET scans. The analyses using linear and exponential models revealed that age had a significant negative correlation with D(2) receptor availability in the post-commissural putamen (postPU) and that D(2) receptor binding in the postPU decreased significantly more with age than in the ventral striatum, suggesting subregional differences in age-related changes in D(2) receptor binding. The postPU, which belongs to the sensorimotor striatum, may be particularly vulnerable to the effects of age in young and middle-aged subjects.