Original Research ARTICLE
Cortical and subcortical neural correlates for respiratory sensation in response to transient inspiratory occlusions in humans
- 1Department of Occupational Therapy and Healthy Aging Center, Chang Gung University, Taiwan
- 2Department of Psychiatry, Linkou Chang Gung Memorial Hospital, Taiwan
- 3Chang Gung University, Laboratory of Brain Imaging and Neural Dynamics (BIND Lab), Taiwan
- 4Graduate Institute of Humanities in Medicine, Taipei Medical University, Taiwan
- 5Brain and Consciousness Research Center, Shuang Ho Hospital, Taipei Medical University, Taiwan
- 6Department of Imaging Physics, University of Texas MD Anderson Cancer Center, United States
- 7Department of Psychology, National Cheng Kung University, Taiwan
- 8Department of Psychiatry, Chang Gung Memorial Hospital, Taiwan
- 9Department of Physiological Sciencees, University of Florida, United States
Cortical and subcortical mechanosensation of breathing can be measured by short respiratory occlusions. However, the corresponding neural substrates involved in the respiratory sensation elicited by a respiratory mechanical stimulus remained unclear. Therefore, we applied the functional magnetic resonance imaging (fMRI) technique to study cortical activations of respiratory mechanosensation. We hypothesized that thalamus, frontal cortex, somatosensory cortex, and inferior parietal cortex would be significantly activated in response to respiratory mechanical stimuli.
We recruited 23 healthy adults to participate in our event-designed fMRI experiment. During the 12-min scan, participants breathed with a specialized face-mask. Single respiratory occlusions of 150 msec were delivered every 2-4 breaths. At least 32 successful occlusions were collected for data analysis.
The results showed significant neural activations in the thalamus, supramarginal gyrus, middle frontal gyrus, inferior frontal triangularis, and caudate (AlphaSim corrected p < 0.05). In addition, subjective ratings of breathlessness were significantly correlated with the levels of neural activations in bilateral thalamus, right caudate, right supramarginal gyrus, left middle frontal gyrus, left inferior triangularis.
Our results demonstrated cortical sources of respiratory sensations elicited by the inspiratory occlusion paradigm in healthy adults were located in the thalamus, supramarginal gyrus, and the middle frontal cortex, inferior frontal triangularis, suggesting subcortical and cortical neural sources of the respiratory mechanosensation are thalamo-cortical based, especially the connections to the premotor area, middle and ventro-lateral prefrontal cortex, as well as the somatosensory association cortex. Finally, level of neural activation in thalamus is associated with the subjective rating of breathlessness, suggesting respiratory sensory information is gated at the thalamic level.
Keywords: respiratory sensation, transient inspiratory occlusions, fMRI — functional magnetic resonance imaging, neural correlates, Cortical and subcortical mapping
Received: 24 Aug 2018;
Accepted: 29 Nov 2018.
Edited by:Yu Ru Kou, National Yang-Ming University, Taiwan
Reviewed by:Elke Vlemincx, Queen Mary University of London, United Kingdom
Kun-Ze Lee, National Sun Yat-sen University, Taiwan
Copyright: © 2018 Chan, Cheng, Wu, Wu, Liu, Shaw, Liu and Davenport. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Prof. Pei-Ying S. Chan, Chang Gung University, Department of Occupational Therapy and Healthy Aging Center, Guishan, Taiwan, firstname.lastname@example.org
Prof. Changwei W. Wu, Taipei Medical University, Graduate Institute of Humanities in Medicine, Taipei, 11049, Taipei County, Taiwan, email@example.com