Functional anatomy of the human thalamus at rest

- A stable, functional parcellation of the human thalamus was achieved using resting state fMRI.
- The obtained thalamic subdivisions exhibited differences in laterality and size.
- All parcels showed a good correspondence with histologically defined thalamic nuclei.
- Thalamo-cortical profiles revealed differences between structural and functional connectivity.

In the present work, we used resting state-fMRI to investigate the functional anatomy of the thalamus at rest by applying an Independent Component Analysis to delineate thalamic substructures into stable and reproducible parcels for the left and right thalamus. We determined 15 functionally distinct thalamic parcels, which differed in laterality and size but exhibited a correspondence with 18 cytoarchitectonally defined nuclei. We characterized their structural connectivity in determining DWI based cortical fiber pathways and found selected projections to different cortical areas. In contrast, the functional connections of these parcels were not confined to certain cortical areas or lobes. We, finally evaluated cortical projections and found particular subcortical and cortical pattern for each parcel, which partly exhibited a correspondence with the thalamo-cortical connectivity maps of the mouse.