Context Processing and the Neurobiology of Post-Traumatic Stress Disorder

Liberzon, Israel; Abelson, James L.

doi:10.1016/j.neuron.2016.09.039

Cited by 361 publications

(375 citation statements)

References 207 publications

(240 reference statements)

Supporting

Mentioning

351

Contrasting

Unclassified

Order By: Relevance

“…Furthermore, the uncinate fasciculus connects the (lateral) prefrontal cortices to the hippocampus, a structure important for contextualizing, including discriminating between threatening and safe contexts. 50 Posttraumatic stress disorder has been associated with dysregulations in context processing, 51 such as enhanced fear generalization 52 and impaired contextual extinction learning 3 and safety learning. 53 Notably, these processes of contextualization depend on the hippocampus and its communication with the prefrontal cortex.…”

Section: Discussionmentioning

confidence: 99%

Decreased uncinate fasciculus tract integrity in male

Koch

Zuiden

Nawijn

et al. 2017

JPN

View full text Add to dashboard Cite

IntroductionApproximately 10% of trauma-exposed individuals have posttraumatic stress disorder (PTSD), 1 characterized by intrusions and avoidance of reminders of the traumatic event, altered cognitions and mood, and hyperarousal.2 The prevailing neurocircuitry model of PTSD postulates amygdala hyperactivity and ventromedial prefrontal cortex (vmPFC) hypoactivity.3,4 The amygdala plays a pivotal role in fear expression and salience processing, 5 whereas the vmPFC is important in top-down control over the fear response.6 Additionally, decreased resting-state functional connectivity between the amygdala and vmPFC has been observed in male patients with PTSD, possibly underlying diminished top-down prefrontal control over the fear response. White matter fibres, which make up more than 40% of total brain volume, 8 allow effective communication between (cortical and subcortical) brain areas. White matter integrity can be investigated noninvasively with diffusion tensor imaging (DTI), which measures the direction and coherence of water diffusion within myelinated and nonmyelinated tissue. 9 The DTI metrics fractional anisotropy (FA) and mean diffusivity (MD) are predominantly used to quantify white matter integrity: FA reflects the extent to which water diffusion is directionally restricted and represents axonal density and coherence, whereas MD (i.e., magnitude of overall diffusion) is sensitive (but not specific) to membrane integrity. 10,11 In line with the prevailing neurocircuitry model of PTSD, lower white matter integrity of tracts connecting the prefrontal cortex with limbic regions, including the cingulum bundle and uncinate fasciculus, has been associated with PTSD and its development. 12-14 The uncinate fasciculus connects the orbital, medial and lateral prefrontal cortex with rostral temporal areas, including the anterior temporal lobe, parahippocampal Background: Posttraumatic stress disorder (PTSD) is a disabling psychiatric disorder that has been associated with lower white matter integrity of tracts connecting the prefrontal cortex with limbic regions. However, previous diffusion tensor imaging (DTI) findings have been inconsistent, showing high variability in the exact location and direction of effects. Methods: We performed probabilistic tractography of the bilateral uncinate fasciculus, cingulum and superior longitudinal fasciculus (both temporal and parietal projections) in male and female police officers with and without PTSD. Results: We included 38 (21 men) police officers with and 39 (20 men) without PTSD in our analyses. Compared with trauma-exposed controls, patients with PTSD showed significantly higher mean diffusivity of the right uncinate fasciculus, the major white matter tract connecting the amygdala to the prefrontal cortex (p = 0.012). No other significant between-group or group × sex differences were observed. Mean diffusivity of the right uncinate fasciculus was positively associated with anxiety symptoms (r = 0.410, p = 0.013) in patients with PTSD as well as with amygdala activi...

show abstract

Section: Discussionmentioning

confidence: 99%

Decreased uncinate fasciculus tract integrity in male

Koch

Zuiden

Nawijn

et al. 2017

JPN

View full text Add to dashboard Cite

show abstract

“…The most commonly implicated neurocircuit model in PTSD involves the fear-associated learning circuitry [3–7]. In both humans and rodents, fear learning can be examined within the framework of classical (Pavlovian) fear conditioning, where an aversive stimulus (unconditioned stimulus; e.g., electric shock) is paired with a neutral stimulus (conditioned stimulus; e.g., a tone), resulting in the neutral stimulus eliciting a conditioned fear response (increased freezing, fear-potentiated startle, or skin conductance response).…”

Section: Fear Learning/threat Detection Circuitrymentioning

confidence: 99%

“…Symptom clusters include intrusive reexperiencing symptoms (memories of trauma, nightmares, flashbacks); avoidance of trauma-related thoughts, memories, contexts or cues; negative mood and cognition; and hyperarousal/hypervigilance [1]. In recent years, multiple studies have examined brain regions involved in PTSD symptomatology in an effort to better understand the underlying mechanisms and to develop more effective treatments [2, 3]. In this mini-review, we focus on three key neural circuits that have been implicated in the pathophysiology and symptom development in this disorder, namely, fear learning/threat detection, context processing and emotion regulation circuits.…”

Section: Introductionmentioning

confidence: 99%

Circuit dysregulation and circuit-based treatments in posttraumatic stress disorder

Sheynin

Liberzon

2017

Neuroscience Letters

Self Cite

View full text Add to dashboard Cite

Posttraumatic stress disorder (PTSD) is a psychiatric disorder that develops in some individuals in the aftermath of exposure to traumatic events, such as actual or threatened death, serious injury or sexual assault. It has been hypothesized that dysregulations in a number of specific neurocircuits, characterized by heightened responsivity of amygdala, dACC and insula, diminished responsivity of mPFC, impaired hippocampal function and deficits in cortical regions, underlie the development and expression of key PTSD symptoms. Here, we concisely describe three functional neural circuits implicated in PTSD pathophysiology and briefly review selected treatment strategies in the context of these neural circuits. We start with the commonly implicated neurocircuit model, namely, the fear learning and threat detection circuits, and then discuss the context processing circuitry, which plays an important role among others, in fear regulation. We then discuss the emotion regulation circuitry, which can further contribute to PTSD pathophysiology, and conclude with a discussion of the therapeutic approaches that might be targeting dysregulation in these circuits in PTSD patients. Specifically, we discuss how exposure-based treatments might be targeting fear learning circuits, and the pharmacological and brain-stimulation interventions aimed to augment these therapies. Finally, we discuss other pharmacological and cognitive therapeutic approaches that can augment or restore the function of the context processing and emotional regulation circuits.

show abstract

“…In line with this suggestion, prior research has demonstrated that threat increases aversive prediction error signal in the ventral striatum, indicating that anxiety may bias the predictive learning of threats to promote survival (Robinson et al 2013a). In the context of anxiety disorders, however, it may be that these responses are exaggerated and/or perpetual, thus contributing to the maintenance of an anxious state (Liberzon and Abelson 2016); this proposal is in line with the finding that visual working memory capacity increases as trait anxiety increases (Moriya and Sugiura 2012). However, future research would benefit from further elucidating the differences between adaptive and maladaptive responding, as some research suggests anxiety disorder patients exhibit impairments in visuospatial short-term memory performance (Jelinek et al 2006;O'Toole et al 2015).…”

Section: Visuospatial Working Memorymentioning

confidence: 99%

The impact of threat of shock-induced anxiety on memory encoding and retrieval

Bolton

Robinson

2017

Learn. Mem.

View full text Add to dashboard Cite

Anxiety disorders are the most common mental health disorders, and daily transient feelings of anxiety (or "stress") are ubiquitous. However, the precise impact of both transient and pathological anxiety on higher-order cognitive functions, including short-and long-term memory, is poorly understood. A clearer understanding of the anxiety-memory relationship is important as one of the core symptoms of anxiety, most prominently in post-traumatic stress disorder (PTSD), is intrusive reexperiencing of traumatic events in the form of vivid memories. This study therefore aimed to examine the impact of induced anxiety (threat of shock) on memory encoding and retrieval. Eighty-six healthy participants completed tasks assessing: visuospatial working memory, verbal recognition, face recognition, and associative memory. Critically, anxiety was manipulated within-subjects: information was both encoded and retrieved under threat of shock and safe (no shock) conditions. Results revealed that visuospatial working memory was enhanced when information was encoded and subsequently retrieved under threat, and that threat impaired the encoding of faces regardless of the condition in which it was retrieved. Episodic memory and verbal short-term recognition were, however, unimpaired. These findings indicate that transient anxiety in healthy individuals has domain-specific, rather than domain-general, impacts on memory. Future studies would benefit from expanding these findings into anxiety disorder patients to delineate the differences between adaptive and maladaptive responding.

show abstract

Context Processing and the Neurobiology of Post-Traumatic Stress Disorder

Cited by 361 publications

References 207 publications

Decreased uncinate fasciculus tract integrity in male

Decreased uncinate fasciculus tract integrity in male

Circuit dysregulation and circuit-based treatments in posttraumatic stress disorder

The impact of threat of shock-induced anxiety on memory encoding and retrieval

Contact Info

Product

Resources

About