Basal ganglia and cerebellar interconnectivity within the human thalamus

Abstract

Basal ganglia and the cerebellum are part of a densely interconnected network. While both subcortical structures process information in basically segregated loops that primarily interact in the neocortex, direct subcortical interaction has been recently confirmed by neuroanatomical studies using viral transneuronal tracers in non-human primate brains. The thalamus is thought to be the main relay station of both projection systems. Yet, our understanding of subcortical basal ganglia and cerebellar interconnectivity within the human thalamus is rather sparse, primarily due to limitation in the acquisition of in vivo tracing. Consequently, we strive to characterize projections of both systems and their potential overlap within the human thalamus by diffusion MRI and tractography. Our analysis revealed a decreasing anterior-to-posterior gradient for pallido-thalamic connections in: (1) the ventral-anterior thalamus, (2) the intralaminar nuclei, and (3) midline regions. Conversely, we found a decreasing posterior-to-anterior gradient for dentato-thalamic projections predominantly in: (1) the ventral-lateral and posterior nucleus; (2) dorsal parts of the intralaminar nuclei and the subparafascicular nucleus, and (3) the medioventral and lateral mediodorsal nucleus. A considerable overlap of connectivity pattern was apparent in intralaminar nuclei and midline regions. Notably, pallidal and cerebellar projections were both hemispherically lateralized to the left thalamus. While strikingly consistent with findings from transneuronal studies in non-human primates as well as with pre-existing anatomical studies on developmentally expressed markers or pathological human brains, our assessment provides distinctive connectional fingerprints that illustrate the anatomical substrate of integrated functional networks between basal ganglia and the cerebellum. Thereby, our findings furnish useful implications for cerebellar contributions to the clinical symptomatology of movement disorders.Electronic supplementary materialThe online version of this article (doi:10.1007/s00429-016-1223-z) contains supplementary material, which is available to authorized users.

Thalamic interactions of cerebellum and basal ganglia

“…Conversely, we (Pelzer et al 2017) demonstrated a decreasing anterior-to-posterior gradient for pallido-thalamic connections in: (1) the ventral-anterior thalamus; (2) the intralaminar nuclei; and (3) midline regions. Moreover, we presented evidence for a decreasing posterior-to-anterior gradient for dentato-thalamic projections predominantly in: (1) the ventral-lateral and posterior nucleus; (2) dorsal parts of the intralaminar nuclei and the subparafascicular nucleus, and (3) the medioventral and lateral mediodorsal nucleus.…”

“…Briefly, in the analysis of connectivity distributions, two different approaches can be taken: (1) tractography-based parcellation as recently shown for the thalamic connections with the cerebellum and basal ganglia in (Lambert et al 2016) or (2) characterization of projections and atlas-based assessment of connectivity fingerprints per thalamic regions as recently demonstrated by our group (Pelzer et al 2017).…”

Best core stabilization exercise to facilitate subcortical neuroplasticity: A functional MRI neuroimaging study

“…The BG-thalamus-cerebellum network might play an important role in procedural knowledge and learning, as evident during the DNS core stabilization exercise. It is plausible that the thalamic ventral lateral nucleus modulates core muscle activation and the learning process while interacting with cortical (SMA, PMC, anterior cingulate cortex) and subcortical targets (BG and cerebellum) [23].…”

Do the Dento-Thalamic Connections of Genetic Absence Epilepsy Rats from Strasbourg Differ from Those of Control Wistar Rats?

“…There are studies that report on connections of the dentate with specific thalamic nuclei in cats, monkeys, and humans using tract tracers and diffusion MRI (Bernard et al, 2013;Holsapple et al, 1991;Jimenez-Castellanos and Reinoso-Suarez, 1985;Pelzer et al, 2017). However, collective data regarding the dento-thalamic connections is rather sparse.…”