Functional connectome of arousal and motor brainstem nuclei in living humans by 7 Tesla resting-state fMRI
Kavita Singh,
Simone Cauzzo,
María Guadalupe García-Gomar,
Matthew Stauder,
Nicola Vanello,
Claudio Passino,
Marta Bianciardi
Affiliations
Kavita Singh
Department of Radiology, Brainstem Imaging Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Building 149, Room 2301, 13th Street, Charlestown, Boston, MA 02129, United States
Simone Cauzzo
Department of Radiology, Brainstem Imaging Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Building 149, Room 2301, 13th Street, Charlestown, Boston, MA 02129, United States; Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy; Research Center E. Piaggio, University of Pisa, Pisa, Italy
María Guadalupe García-Gomar
Department of Radiology, Brainstem Imaging Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Building 149, Room 2301, 13th Street, Charlestown, Boston, MA 02129, United States; Escuela Nacional de Estudios Superiores, Juriquilla, Universidad Nacional Autónoma de México, Querétaro, México
Matthew Stauder
Department of Radiology, Brainstem Imaging Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Building 149, Room 2301, 13th Street, Charlestown, Boston, MA 02129, United States
Nicola Vanello
Dipartimento di Ingegneria dell'Informazione, University of Pisa, Pisa, Italy
Claudio Passino
Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy; Fondazione Toscana Gabriele Monasterio, Pisa, Italy
Marta Bianciardi
Department of Radiology, Brainstem Imaging Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Building 149, Room 2301, 13th Street, Charlestown, Boston, MA 02129, United States; Division of Sleep Medicine, Harvard University, Boston, MA, United States; Corresponding author at: Department of Radiology, Brainstem Imaging Laboratory, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Building 149, Room 2301, 13th Street, Charlestown, Boston, MA 02129, United States.
Brainstem nuclei play a pivotal role in many functions, such as arousal and motor control. Nevertheless, the connectivity of arousal and motor brainstem nuclei is understudied in living humans due to the limited sensitivity and spatial resolution of conventional imaging, and to the lack of atlases of these deep tiny regions of the brain. For a holistic comprehension of sleep, arousal and associated motor processes, we investigated in 20 healthy subjects the resting-state functional connectivity of 18 arousal and motor brainstem nuclei in living humans. To do so, we used high spatial-resolution 7 Tesla resting-state fMRI, as well as a recently developed in-vivo probabilistic atlas of these nuclei in stereotactic space. Further, we verified the translatability of our brainstem connectome approach to conventional (e.g. 3 Tesla) fMRI. Arousal brainstem nuclei displayed high interconnectivity, as well as connectivity to the thalamus, hypothalamus, basal forebrain and frontal cortex, in line with animal studies and as expected for arousal regions. Motor brainstem nuclei showed expected connectivity to the cerebellum, basal ganglia and motor cortex, as well as high interconnectivity. Comparison of 3 Tesla to 7 Tesla connectivity results indicated good translatability of our brainstem connectome approach to conventional fMRI, especially for cortical and subcortical (non-brainstem) targets and to a lesser extent for brainstem targets. The functional connectome of 18 arousal and motor brainstem nuclei with the rest of the brain might provide a better understanding of arousal, sleep and accompanying motor functions in living humans in health and disease.
