Disruption of thalamic functional connectivity is a neural correlate of dexmedetomidine-induced unconsciousness
Oluwaseun Akeju,
Marco L Loggia,
Ciprian Catana,
Kara J Pavone,
Rafael Vazquez,
James Rhee,
Violeta Contreras Ramirez,
Daniel B Chonde,
David Izquierdo-Garcia,
Grae Arabasz,
Shirley Hsu,
Kathleen Habeeb,
Jacob M Hooker,
Vitaly Napadow,
Emery N Brown,
Patrick L Purdon
Affiliations
Oluwaseun Akeju
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, United States
Marco L Loggia
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States; Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
Ciprian Catana
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States
Kara J Pavone
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, United States
Rafael Vazquez
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, United States
James Rhee
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, United States
Violeta Contreras Ramirez
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, United States
Daniel B Chonde
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States
David Izquierdo-Garcia
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States
Grae Arabasz
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States
Shirley Hsu
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States
Kathleen Habeeb
Clinical Research Center, Massachusetts General Hospital, Boston, United States
Jacob M Hooker
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States
Vitaly Napadow
MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Charlestown, United States; Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
Emery N Brown
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, United States; Department of Brain and Cognitive Science and Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, United States; Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, United States
Patrick L Purdon
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, United States; Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, United States
Understanding the neural basis of consciousness is fundamental to neuroscience research. Disruptions in cortico-cortical connectivity have been suggested as a primary mechanism of unconsciousness. By using a novel combination of positron emission tomography and functional magnetic resonance imaging, we studied anesthesia-induced unconsciousness and recovery using the α2-agonist dexmedetomidine. During unconsciousness, cerebral metabolic rate of glucose and cerebral blood flow were preferentially decreased in the thalamus, the Default Mode Network (DMN), and the bilateral Frontoparietal Networks (FPNs). Cortico-cortical functional connectivity within the DMN and FPNs was preserved. However, DMN thalamo-cortical functional connectivity was disrupted. Recovery from this state was associated with sustained reduction in cerebral blood flow and restored DMN thalamo-cortical functional connectivity. We report that loss of thalamo-cortical functional connectivity is sufficient to produce unconsciousness.
