Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation

Breathing high concentrations of carbon dioxide (CO2) can trigger panic and anxiety in humans. CO2 inhalation has been hypothesized to activate neural systems similar to those underlying fear learning, especially those involving the amygdala. Amygdala activity is also upregulated by stress. Recently...

Full description

Bibliographic Details
Main Authors: Mohammed Mostafizur eRahman, Christian M Kerskens, Sumantra eChattarji, Shane M O‘Mara
Format: Article
Language:English
Published: Frontiers Media S.A. 2014-09-01
Series:Frontiers in Behavioral Neuroscience
Subjects:
MRI
Online Access:http://journal.frontiersin.org/Journal/10.3389/fnbeh.2014.00311/full
id doaj-f7a9176e940444f4a9dd692700fa26ed
record_format Article
spelling doaj-f7a9176e940444f4a9dd692700fa26ed2020-11-25T01:08:11ZengFrontiers Media S.A.Frontiers in Behavioral Neuroscience1662-51532014-09-01810.3389/fnbeh.2014.0031199951Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalationMohammed Mostafizur eRahman0Christian M Kerskens1Sumantra eChattarji2Shane M O‘Mara3National Centre for Biological SciencesTrinity College DublinNational Centre for Biological SciencesTrinity College DublinBreathing high concentrations of carbon dioxide (CO2) can trigger panic and anxiety in humans. CO2 inhalation has been hypothesized to activate neural systems similar to those underlying fear learning, especially those involving the amygdala. Amygdala activity is also upregulated by stress. Recently, however, a separate pathway has been proposed for interoceptive panic and anxiety signals, as patients exhibited CO2-inhalation induced panic responses despite bilateral lesions of the amygdala. This paradoxical observation has raised the possibility that cortical circuits may underlie these responses. We sought to examine these divergent models by comparing in vivo brain activation in unstressed and chronically-stressed rats breathing CO2. Regional cerebral blood flow measurements using functional Magnetic Resonance Imaging (fMRI) in lightly-anaesthetized rats showed especially strong activation of the somatosensory cortex by CO2 inhalation in the unstressed group. Strikingly, prior exposure to chronic stress occluded this effect on cortical activity. This lends support to recent clinical observations and highlights the importance of looking beyond the traditional focus on limbic structures, such as the hippocampus and amygdala, to investigate a role for cortical areas in panic and anxiety in humans.http://journal.frontiersin.org/Journal/10.3389/fnbeh.2014.00311/fullCarbon DioxideHypercapniaPanicSomatosensory CortexStress, PsychologicalMRI
collection DOAJ
language English
format Article
sources DOAJ
author Mohammed Mostafizur eRahman
Christian M Kerskens
Sumantra eChattarji
Shane M O‘Mara
spellingShingle Mohammed Mostafizur eRahman
Christian M Kerskens
Sumantra eChattarji
Shane M O‘Mara
Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation
Frontiers in Behavioral Neuroscience
Carbon Dioxide
Hypercapnia
Panic
Somatosensory Cortex
Stress, Psychological
MRI
author_facet Mohammed Mostafizur eRahman
Christian M Kerskens
Sumantra eChattarji
Shane M O‘Mara
author_sort Mohammed Mostafizur eRahman
title Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation
title_short Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation
title_full Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation
title_fullStr Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation
title_full_unstemmed Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation
title_sort chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation
publisher Frontiers Media S.A.
series Frontiers in Behavioral Neuroscience
issn 1662-5153
publishDate 2014-09-01
description Breathing high concentrations of carbon dioxide (CO2) can trigger panic and anxiety in humans. CO2 inhalation has been hypothesized to activate neural systems similar to those underlying fear learning, especially those involving the amygdala. Amygdala activity is also upregulated by stress. Recently, however, a separate pathway has been proposed for interoceptive panic and anxiety signals, as patients exhibited CO2-inhalation induced panic responses despite bilateral lesions of the amygdala. This paradoxical observation has raised the possibility that cortical circuits may underlie these responses. We sought to examine these divergent models by comparing in vivo brain activation in unstressed and chronically-stressed rats breathing CO2. Regional cerebral blood flow measurements using functional Magnetic Resonance Imaging (fMRI) in lightly-anaesthetized rats showed especially strong activation of the somatosensory cortex by CO2 inhalation in the unstressed group. Strikingly, prior exposure to chronic stress occluded this effect on cortical activity. This lends support to recent clinical observations and highlights the importance of looking beyond the traditional focus on limbic structures, such as the hippocampus and amygdala, to investigate a role for cortical areas in panic and anxiety in humans.
topic Carbon Dioxide
Hypercapnia
Panic
Somatosensory Cortex
Stress, Psychological
MRI
url http://journal.frontiersin.org/Journal/10.3389/fnbeh.2014.00311/full
work_keys_str_mv AT mohammedmostafizurerahman chronicimmobilizationstressoccludesinvivocorticalactivationinananimalmodelofpanicinducedbycarbondioxideinhalation
AT christianmkerskens chronicimmobilizationstressoccludesinvivocorticalactivationinananimalmodelofpanicinducedbycarbondioxideinhalation
AT sumantraechattarji chronicimmobilizationstressoccludesinvivocorticalactivationinananimalmodelofpanicinducedbycarbondioxideinhalation
AT shanemomara chronicimmobilizationstressoccludesinvivocorticalactivationinananimalmodelofpanicinducedbycarbondioxideinhalation
_version_ 1725183827807043584