Functional Connectivity of the Human Paraventricular Thalamic Nucleus: Insights From High Field Functional MRI

Abstract

The paraventricular thalamic nucleus (PVT) is a small but highly connected nucleus of the dorsal midline thalamus. The PVT has garnered recent attention as a context-sensitive node within the thalamocortical arousal system that modulates state-dependent motivated behaviors. Once considered related to generalized arousal responses with non-specific impacts on behavior, accumulating evidence bolsters the contemporary view that discrete midline thalamic subnuclei belong to specialized corticolimbic and corticostriatal circuits related to attention, emotions, and cognition. However, the functional connectivity patterns of the human PVT have yet to be mapped. Here, we combined high-quality, high-resolution 7T and 3T resting state MRI data from 121 young adult participants from the Human Connectome Project (HCP) and thalamic subnuclei atlas masks to investigate resting state functional connectivity of the human PVT. The 7T results demonstrated extensive positive functional connectivity with the brainstem, midbrain, ventral and dorsal medial prefrontal cortex (mPFC), anterior and posterior cingulate, ventral striatum, hippocampus, and amygdala. These connections persist upon controlling for functional connectivity of the rest of the thalamus. Whole-brain contrasts provided further evidence that, compared to three nearby midline thalamic subnuclei, functional connectivity of the PVT is strong with the hippocampus, amygdala, ventral and dorsal mPFC, and middle temporal gyrus. These findings suggest that, even during rest, the human PVT is functionally coupled with many regions known to be structurally connected to rodent and non-human primate PVT. Further, cosine similarity analysis results suggested the PVT is integrated into the default mode network (DMN), an intrinsic connectivity network associated with episodic memory and self-referential thought. The current work provides a much-needed foundation for ongoing and future work examining the functional roles of the PVT in humans.

Alterations in 18F-FDG PET/MRI and 15O-Water PET Brain Findings in Patients With Neurological Symptoms After COVID-19 Vaccination

“…The patient with a mildly significant decrease in perfusion in the bilateral thalamus and bilateral cerebellum on the 15 O-water PET did not show any abnormalities on their MRI perfusion image, which may indicate minor perfusion changes or nonspecific findings, although thalamus connectome data have suggested an association with anxiety. 15 , 16 However, the diffuse increase in perfusion in the cerebral white matter was observed on both the 15 O-water PET and MRI perfusion images. Previous studies have shown that increased cerebral blood volume and CBF can be detected in normal-appearing white matter in patients with inflammatory conditions, such as multiple sclerosis.…”

Molecular and spatial profiling of the paraventricular nucleus of the thalamus

“…To examine how PVT neurons undergo experience-dependent changes in gene expression, future investigations should include high throughput RNA-sequencing of the PVT following different biological conditions with the goal of comparing them with our atlas to identify potential biomarkers for therapeutic targeting. Indeed, based on the role of the rodent PVT in emotional processing and motivated behaviors, there is growing interest in the human PVT as a putative target for affective and substance abuse disorders, particularly since the human PVT has similar connectivity with the rodent PVT [132]. Excitingly, the existence of some markers (e.g.…”

Why do mothers never stop grieving for their deceased children? Enduring alterations of brain connectivity and function

“…We focused on delineating the circuitry of paraventricular thalamic nucleus (PVT), in view of its established and emerging roles in the encoding and integration of emotionally salient long-term memories (Do Monte et al, 2016;Kark et al, 2021;Kooiker et al, 2021) and the influence of these memories on behaviors during emotional conflicts (Choi et al, 2019). We assessed the impact of maternal grief on resting-state functional connectivity (RSFC) of the PVT.…”

“…For one grief participant with a wider third ventricle width, the PVT seeds were slightly nudged away from x = 0 using MRICRON to fall on the paraventricular gray matter. This approach was based on our recently published work demonstrating the intrinsic structure and connectivity of the PVT in humans (Kark et al, 2021). Given the small size of the PVT and to address potential confounding effects of neighboring nuclei, we created a midline subnuclei control seed encompassing all midline nuclei using the Thalamus Atlas of the Swiss Federal Institute of Technology (ETH) in Zurich and University of Zurich, Switzerland (Krauth et al, 2010;Jakab et al, 2012).…”

“…Subject-level seed-to-voxel PVT RSFC maps were calculated, controlling for the midline subnuclei, and subsequently entered a group-level independent samples t-test in SPM12. Group-level analyses were spatially constrained to key nodes of PVT 1 http://people.cas.sc.edu/rorden/mricron/index.html functional connectivity (Kark et al, 2021;Kooiker et al, 2021), which include the orbitofrontal cortex, cingulate cortex, amygdala, hippocampus, striatum, and the insula, to increase the sensitivity of the analysis and thresholded at p < 0.05 uncorrected.…”