Insular dopamine D 2 receptors and novelty seeking personality in Parkinson's disease

Novelty seeking is a temperament trait characterized by impulsiveness and exploratory behavior. Dopamine has been suggested to be the primary neurotransmitter modulator of novelty seeking, and in young healthy subjects, a correlation between increased novelty seeking and decreased insular cortical dopamine D 2 receptor availability has been reported. The proposed link between dopamine deficiency and reduction in novelty seeking in Parkinson's disease is controversial. The present study examined whether a link between insular D 2 receptor availability and novelty seeking can be replicated in Parkinson's disease patients. [ 11 C]FLB 457 positron emission tomography imaging was carried out in 28 patients with Parkinson's disease, and the data were analyzed using voxel‐based statistical analysis. The results demonstrated a negative correlation between the novelty seeking score and the dopamine D 2 availability bilaterally in the insular cortex (corrected P = 0.001; r = −0.74 [right hemisphere]; r = −0.66 [left hemisphere]). The results provide further support for a relationship between novelty seeking and insular D 2 receptors. They indicate that the association is cross‐cultural, independent of age, and unaffected by dopaminergic degeneration. © 2004 Movement Disorder Society