Variation at the DRD4 promoter modulates extraversion in Caucasians

Abstract

between OCD patients and controls (RT: 537739 vs 528750 ms; HR: 98.671 vs 98.272%), respectively. Neural generators of the N1 were estimated with the LORETA method, indicating a major source in the left temporoparietal region (Brodmann areas (BA) 19/37/39, Figure 1b) and a weaker mirror image source on the right. Comparing individual source solutions statistically (voxel-wise), group H and the control group differed in the medial frontal (BA 23/24) and lateral temporo-occipital (BA 19) cortex (Figure 1c). This is the first demonstration that BDV activity (amount of BDV-CICs) is associated with diseaserelevant and attention-related cognitive changes (increased N1) in humans, in particular in secondary visual areas and the anterior cingulate gyrus. The increased N1 amplitude in group H patients may be explained by defective thalamic filter mechanisms, given a proposed modulation by thalamic input to the cortex. 10 Indeed, functional neuroimaging studies 9 strongly suggest that OCD involves hyperactivity of striato-thalamo-cortical networks. The present findings are consistent with such a hyperactivity and suggest that this may be modulated by BDV infection possibly through interference of viral components with neurotransmitters (eg, glutamate and aspartate). 4 Future studies should validate these findings and further investigate possible mechanisms of this neurotropic virus in relation to altered cortical activity in psychiatric disorders.

The molecular genetic architecture of human personality: beyond self-report questionnaires

“…Additionally, a transient expression method revealed that the T variant of the C-521T polymorphism reduces transcriptional efficiency. Several other studies have confirmed this association [99][100][101][102] with one exception. 103 In African Americans, a significant three-way interaction (gender, C-616G genotype and C-521T genotype) was observed for NEO Extraversion.…”

“…In a German study, 100 carriers of the single 120 bp tandem repeat scored higher on Extraversion whereas carriers of the C-521T 'T' allele scored lower on this scale. Together, when gender, age and the haplotype were included in the analysis a considerable fraction of the variance in Extraversion was explained.…”

Neurophysiological markers of novelty processing are modulated by COMT and DRD4 genotypes

“…Of particular relevance to the present investigation, polymorphisms of the DRD4, including the single nucleotide polymorphism located at position −521 in the promoter region (C to T substitution), have been implicated in ADHD (Bellgrove et al, 2005;Faraone et al, 2005), a disorder characterized by increased distractibility. Several studies have also linked this polymorphism to the personality trait novelty seeking and have demonstrated that CC homozygotes have higher novelty seeking scores (Bookman et al, 2002;Eichhammer et al, 2005;Golimbet et al, 2006Golimbet et al, , 2007Okuyama et al, 2000;Ronai et al, 2001; but see Mitsuyasu et al, 2001, for an exception). On the molecular level, the T-allele results in 40% reduction of transcriptional efficiency (Okuyama et al, 1999, but see Kereszturi et al, 2006).…”

Friendships Moderate an Association Between a Dopamine Gene Variant and Political Ideology

“…These alterations in cortical arousal affect "approach traits" such as noveltyseeking and sensation-seeking, which in turn affect personality and behavior (Eichhammer et al 2005). People who score high on measures of novelty-seeking have less tolerance for monotony and constantly seek the new and unusual (to them) in order to alter dopamine levels to affect mood; at the extremes, they are characterized as impulsive, exploratory, fickle, excitable, quick-tempered, and extravagant (Puttonen et al 2005).…”