Linking novelty seeking and harm avoidance personality traits to basal ganglia: volumetry and mean diffusivity

Abstract

Novelty Seeking (NS) and Harm Avoidance (HA) temperamental traits are related to approaching or avoiding motivational circuits relying on the integrity and functionality of distributed brain areas implicated in arousal and action. The present study verified whether and how macro- and micro-structural variations of basal ganglia are correlated with scores obtained in the NS and HA temperamental scales of the Temperament and Character Inventory by Cloninger. To this aim, 125 healthy adults aged 18-67 years of both sexes completed the Temperament and Character Inventory and underwent a high-resolution T1-weighted magnetic resonance imaging and a diffusion tensor imaging using a 3T scanner. The scores obtained in the temperamental scales were associated with volumes, mean diffusivity and fractional anisotropy measures of basal ganglia of both hemispheres separately, by using linear regression analyses. We found increased bilateral caudate and pallidum volumes associated with higher NS scores, as well as increased mean diffusivity in the bilateral putamen associated with higher HA scores. Macro- and micro-structural variations of basal ganglia regions contribute to explain the biological variance associated with NS or HA personality phenotype. The present findings evidencing some brain-temperament relationships highlight the importance of obtaining macro- and micro-structural measures in relation to individual differences.

Mean diffusivity of basal ganglia and thalamus specifically associated with motivational states among mood states

“…More elaborate structural changes, such as dendritic sprouting, neurogenesis, and angiogenesis, occur over a period of days to weeks. Given the rapid plasticity of MD, it may be related to individual cognitive states and not just individual traits, as shown previously (Laricchiuta et al 2013).…”

“…Previously, neurological studies have shown that patients with Parkinson's disease exhibited a greater MDDS (Péran et al 2010). Studies of normal samples have shown that the major personalities are associated with MD in overlapping areas of the dopaminergic system (Laricchiuta et al 2013;Takeuchi et al 2015). However, it was not clear which factor contributed to MDDS in previous studies, because different personalities were associated with MD in similar areas.…”

“…For example, a previous study detected an association between MD in the putamen and harm avoidance (Laricchiuta et al 2013). In our sample, the score on the Vigor subscale of POMS was also significantly and negatively correlated with the harm avoidance score and all its subscales (P \ 0.001, simple regression analyses).…”

“…In contrast, a greater tissue density, such as the presence of more cellular structures [e.g., capillaries, synapses, and macromolecular proteins; the shape of neurons or glia; or enhanced tissue organization (strengthening of the axonal or dendritic backbones and surrounding tissue)], may prevent the free diffusion of water molecules and may also be expected to cause the MD value to decrease (Assaf and Pasternak 2008;Ni et al 2010;Sagi et al 2012). MD differences have been shown to underlie individual cognitive differences and brain pathology (Laricchiuta et al 2013;Piras et al 2010). MD in areas of the dopaminergic system (MDDS), particularly those of the subcortical areas, such as the putamen, caudate, and globus pallidum, is associated with several conditions that are known to be related to alterations of the dopaminergic system.…”

Cognitive and neural correlates of the 5-repeat allele of the dopamine D4 receptor gene in a population lacking the 7-repeat allele

“…It can sensitively detect the neural plasticity involving dopamine function change (Razek et al, 2011;Takeuchi et al, 2014c). It also shows robust correlation with the motivational state, which is highly relevant to dopamine as well as traits crucially related to dopamine (Bjørnebekk et al, 2012;Laricchiuta et al, 2013;Picerni et al, 2013;Takeuchi and Kawashima, 2013). Thus, DRD polymorphism may well be associated with these DTI measures, and its investigation can reveal new insights into the effects of DRD4 polymorphisms.…”