Preferential networks of the mediodorsal nucleus and centromedian–parafascicular complex of the thalamus—A DTI tractography study

Abstract

Distinct thalamic nuclei, like the mediodorsal (MD) nucleus and the centromedian/parafascicular complex (CM/Pf), are embedded in different basal ganglia-thalamocortical loops, which were shown to integrate cognitive and emotional aspects of human behavior. Despite well described connections on a microscopic scale, derived from tracing studies in animals, little is known about the intrinsic anatomical connections of these nuclei in humans. This lack of knowledge limits not only interpretation of functional imaging studies but also estimation of direct effects of deep brain stimulation which treats diseases as different as epilepsy or major depression. Therefore, non-invasive diffusion tensor imaging (DTI) studies are key to analyzing connectivity patterns and elaborate approaches to close this gap. For our study, we explored the structural connectivity of the MD thalamic nuclei and the CM/Pf complex towards five cortical and six subcortical regions by using a preferential fiber calculation. We found both thalamic nuclei to be preferentially associated to distinct networks: whereas the MD is preferentially connected to prefrontal and limbic cortical regions, the CM is linked to subcortical regions. The anterior insula was the only cortical region associated with the subcortical network of the CM and the cortical network of the MD comprised one subcortical hub, the caudate nucleus, suggesting an integrative role of these two regions. Adding to predescribed anatomical tract tracing connectivities in animal studies, our finding lends support to the existence of similar basal ganglia-thalamocortical circuits in humans and we could show a robust distinction of preferential connectivity for both thalamic nuclei.

Association between heart rate variability and fluctuations in resting-state functional connectivity

“…3 and 4) analysis and weakly at the inter-individual (Fig. 8) analysis, follows a well-described anatomical route of a preferential anatomical connectivity (Eckert et al, 2012) and salience related activations (Metzger et al, 2010). This overlap, which would indeed speak in favor of a common framework to explain dynamics of connectivity as representations varying psychological states, needs however to be regarded with caution due to the weak significance and potential bias (specificity) by the length of the sliding window used for analysis.…”

Centromedian-Parafascicular Complex Deep Brain Stimulation for Tourette Syndrome

“…Other targets include the globus pallidus, the anterior limb of the internal capsule, the nucleus accumbens, and the subthalamic nucleus. 19 The role of the CM-Pf in motor and executive functions such as attention and motor control 20–22 and its connections with many subcortical regions 22,23 may contribute to the efficacy of CM-Pf DBS for TS. The literature suggests good tic control with CM-Pf DBS.…”

Deep Brain Stimulation for Tourette’s Syndrome: The Case for Targeting the Thalamic Centromedian–Parafascicular Complex

“…The striatum receives most of the CM-Pf efferents. Although Eckert et al (10) recently confirmed the extended connectivity between CM-Pf and subcortical structures in a tractography study of normal human subjects, CM-Pf connections have been mainly investigated in studies in rodents and primates, which found that CM (or its rodent equivalent, the lateral Pf nucleus) and Pf have complementary functions.…”