Periaqueductal Gray

Keay, Kevin A.; Bandler, Richard

doi:10.1016/b978-0-12-374245-2.00010-3

Cited by 30 publications

(27 citation statements)

References 160 publications

(218 reference statements)

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“…The PAG is commonly thought to be involved in regulating systems of the body's internal milieu, particularly when dealing with moments of motivated behavior when energy expenditures are higher, such as during episodes of pain, sexual behavior, distress, and feeling threatened (Fanselow, 1991;LeDoux, 2012;Keay and Bandler, 2015). Our observations in this study broaden our understanding of the PAG's functional repertoire by demonstrating that changes in PAG activity are reliably associated with different levels of cognitive demand.…”

Section: Discussionmentioning

confidence: 58%

“…As a final exploratory analysis, we examined the involvement of midbrain and subcortical structures with high numbers of dopamine receptors (Pauli et al, 2018) because of their established involvement in cognitive control and working memory. Many of these subcortical structures, including the hypothalamus (Keay and Bandler, 2015), VTA (Omelchenko and Sesack, 2010), and SN (Carrive and Morgan, 2012), have reciprocal connections with the PAG. This analysis revealed load-dependent modulation of activity in a number of regions (Fig.…”

Section: Functional Neuroimaging Findingsmentioning

confidence: 99%

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Functional Involvement of Human Periaqueductal Gray and Other Midbrain Nuclei in Cognitive Control

et al. 2019

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Recent theoretical advances have motivated the hypothesis that the periaqueductal gray (PAG) participates in behaviors that involve changes in the autonomic control of visceromotor activity, including during cognitively demanding tasks. We used ultra-high-field (7 tesla) fMRI to measure human brain activity at 1.1 mm resolution while participants completed a working memory task. Consistent with prior work, participants were less accurate and responded more slowly with increasing memory load-signs of increasing task difficulty. Whole-brain fMRI analysis revealed increased activity in multiple cortical areas with increasing working memory load, including frontal and parietal cortex, dorsal cingulate, supplementary motor area, and anterior insula. Several dopamine-rich midbrain nuclei, such as the substantia nigra and ventral tegmental area, also exhibited load-dependent increases in activation. To investigate PAG involvement during cognitive engagement, we developed an automated method for segmenting and spatially normalizing the PAG. Analyses using cross-validated linear support vector machines showed that the PAG discriminated high versus low working memory load conditions with 95% accuracy in individual subjects based on activity increases in lateral and ventrolateral PAG. Effect sizes in the PAG were comparable in magnitude to those in many of the cortical areas. These findings suggest that cognitive control is not only associated with cortical activity in the frontal and parietal lobes, but also with increased activity in the subcortical PAG and other midbrain regions involved in the regulation of autonomic nervous system function.

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Section: Discussionmentioning

confidence: 58%

Section: Functional Neuroimaging Findingsmentioning

confidence: 99%

Functional Involvement of Human Periaqueductal Gray and Other Midbrain Nuclei in Cognitive Control

et al. 2019

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“…Here, the PAG refers to the grey matter located around the cerebral aqueduct of the midbrain, which, when activated, can engage evolutionarily conserved defensive responses that function to resist or to avoid an impending threat (e.g. fight, flight, faint; De Oca, DeCola, Maren, & Fanselow, 1998;Brandão, Zanoveli, Ruiz-Martinez, Oliveira, & Landeira-Fernandez, 2008;Fenster, Lebois, Ressler, & Suh, 2018; for a review, see Keay & Bandler, 2014). Terpou et al (2019aTerpou et al ( , 2019b recently investigated the functional characteristics of the PAG during subliminal, trauma-related stimulus conditions in participants with PTSD as compared to healthy individuals.…”

Section: The Default Mode Network Under Threat In the Aftermath Of Trmentioning

confidence: 99%

The sense of self in the aftermath of trauma: lessons from the default mode network in posttraumatic stress disorder

Lanius

Terpou

McKinnon

2020

European Journal of Psychotraumatology

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Trauma can profoundly affect the sense of self, where both cognitive and somatic disturbances to the sense of self are reported clinically by individuals with posttraumatic stress disorder (PTSD). These disturbances are captured eloquently by clinical accounts, such as, 'I do not know myself anymore,' 'I will never be able to experience normal emotions again,' and, 'I feel dead inside.' Self-related thoughts and experiences are represented neurobiologically by a large-scale, cortical network located along the brain's mid-line and referred to as the default mode network (DMN). Recruited predominantly during rest in healthy participants, the DMN is also active during self-referential and autobiographical memory processing-processes which, collectively, are thought to provide the foundation for a stable sense of self that persists across time and may be available for conscious access. In participants with PTSD, however, the DMN shows substantially reduced resting-state functional connectivity as compared to healthy individuals, with greater reductions associated with heightened PTSD symptom severity. Critically, individuals with PTSD describe frequently that their traumatic experiences have become intimately linked to their perceived sense of self, a perception which may be mediated, in part, by alterations in the DMN. Accordingly, identification of alterations in the functional connectivity of the DMN during rest, and during subliminal, trauma-related stimulus conditions, has the potential to offer critical insight into the dynamic interplay between trauma-and self-related processing in PTSD. Here, we discuss DMN-related alterations during these conditions, pointing further towards the clinical significance of these findings in relation to past-and present-centred therapies for the treatment of PTSD. El sentido del Yo luego de experimentar Trastorno de Estrés Postraumático: Lesiones desde la Red Neuronal por defecto

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“…1,4 The periaqueductal gray (PAG) is a midbrain structure innervated by the superior colliculus, in addition to other brainstem nuclei, the spinal cord, the amygdala, the hypothalamus, and the cortex and is thus well positioned to coordinate defensive responses to a perceived threat. [5][6][7] Defensive responses refer to a set of behavioral states that are engaged through the excitation or the inhibition of the sympathetic nervous system, as well as through the expression of opioid-or endocannabinoid-mediated analgesia. 8,9 Behaviorally, defensive responses may take the form of an active (i.e., fight and flight) or of a passive state (i.e., tonic immobility and shutdown) and their expression is dependent on the context and the level of threat perceived.…”

Section: Introductionmentioning

confidence: 99%

The Threatful Self: Midbrain Functional Connectivity to Cortical Midline and Parietal Regions During Subliminal Trauma-Related Processing in PTSD

et al. 2019

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Background The innate alarm system consists of a subcortical network of interconnected midbrain, lower brainstem, and thalamic nuclei, which together mediate the detection of evolutionarily-relevant stimuli. The periaqueductal gray is a midbrain structure innervated by the innate alarm system that coordinates the expression of defensive states following threat detection. In participants with post-traumatic stress disorder, the periaqueductal gray displays overactivation during the subliminal presentation of trauma-related stimuli as well as altered resting-state functional connectivity. Aberrant functional connectivity is also reported in post-traumatic stress disorder for the default-mode network, a large-scale brain network recruited during self-referential processing and autobiographical memory. Here, research lacks investigation on the extent to which functional interactions are displayed between the midbrain and the large-scale cortical networks in post-traumatic stress disorder. Methods Using a subliminal threat presentation paradigm, we investigated psycho-physiological interactions during functional neuroimaging in participants with post-traumatic stress disorder (n = 26) and healthy control subjects (n = 20). Functional connectivity of the periaqueductal gray was investigated across the whole-brain of each participant during subliminal exposure to trauma-related and neutral word stimuli. Results As compared to controls during subliminal threat presentation, the post-traumatic stress disorder group showed significantly greater periaqueductal gray functional connectivity with regions of the default-mode network (i.e., angular gyrus, precuneus, superior frontal gyrus). Moreover, multiple regression analyses revealed that the functional connectivity between the periaqueductal gray and the regions of the default-mode network correlated positively to symptoms of avoidance and state dissociation in post-traumatic stress disorder. Conclusion Given that the periaqueductal gray engages the expression of defensive states, stronger midbrain functional coupling with the default-mode network may have clinical implications to self-referential and trauma-related processing in participants with post-traumatic stress disorder.

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Periaqueductal Gray

Cited by 30 publications

References 160 publications

Functional Involvement of Human Periaqueductal Gray and Other Midbrain Nuclei in Cognitive Control

Functional Involvement of Human Periaqueductal Gray and Other Midbrain Nuclei in Cognitive Control

The sense of self in the aftermath of trauma: lessons from the default mode network in posttraumatic stress disorder

The Threatful Self: Midbrain Functional Connectivity to Cortical Midline and Parietal Regions During Subliminal Trauma-Related Processing in PTSD

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