Functional mapping of thalamic nuclei and their integration into cortico-striatal-thalamo-cortical loops via ultra-high resolution imaging—from animal anatomy to in vivo imaging in humans

TLDR

The thalamus is a key hub in cortico‑striatal‑thalamo‑cortical circuits, yet functional and structural imaging of its rich cytoarchitectonics has been limited by spatial resolution, creating a translational gap between animal histology and human cognition studies. This review examines neuroscientific and clinical perspectives and aims to bridge that gap by leveraging ultra‑high‑resolution MRI. By applying ultra‑high‑field MR techniques, the authors map thalamic nuclei with cellular‑level detail, integrating animal anatomy with in‑vivo human imaging to elucidate cortico‑striatal‑thalamo‑cortical loops.

Abstract

The thalamus, a crucial node in the well-described cortico-striatal-thalamo-cortical circuits, has been the focus of functional and structural imaging studies investigating human emotion, cognition and memory. Invasive work in animals and post-mortem investigations have revealed the rich cytoarchitectonics and functional specificity of the thalamus. Given current restrictions in the spatial resolution of non-invasive imaging modalities, there is, however, a translational gap between functional and structural information on these circuits in humans and animals as well as between histological and cellular evidence and their relationship to psychological functioning. With the advance of higher field strengths for MR approaches, better spatial resolution is now available promising to overcome this conceptual problem. We here review these two levels, which exist for both neuroscientific and clinical investigations, and then focus on current attempts to overcome conceptual boundaries of these observations with the help of ultra-high resolution imaging.