Conditioned respiratory threat in the subdivisions of the human periaqueductal gray
Abstract
The sensation of breathlessness is the most threatening symptom of respiratory disease. The different subdivisions of the midbrain periaqueductal gray (PAG) are intricately (and differentially) involved in integrating behavioural responses to threat in animals, while the PAG has previously only been considered as a single entity in human research. Here we investigate how these individual PAG columns are differently involved with respiratory threat. Eighteen healthy subjects were conditioned to associate shapes with certain or uncertain impending respiratory load, and scanned the following day during anticipation and application of inspiratory loading using 7 T functional MRI. We showed activity in the ventrolateral PAG (vlPAG) during anticipation of resistive loading, with activity in the lateral PAG (lPAG) during resistive loading, showing spatially and temporally distinct functions within this structure. We propose that lPAG is involved with sensorimotor responses to breathlessness, while the vlPAG operates within the threat perception network for impending breathlessness.
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Ethics
Human subjects: The Oxfordshire Clinical Research Ethics Committee approved the study and volunteers gave written, informed consent prior to testing.
Reviewing Editor
- Jan-Marino Ramirez, Seattle Children's Research Institute and University of Washington, United States
Version history
- Received: October 16, 2015
- Accepted: February 26, 2016
- Accepted Manuscript published: February 27, 2016 (version 1)
- Version of Record published: March 30, 2016 (version 2)
- Version of Record updated: April 22, 2016 (version 3)
Copyright
© 2016, Faull et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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