Conditioned Fear Extinction and Generalization in Posttraumatic Stress Disorder

2011 ◽  
Author(s):  
Seth D. Norrholm
2019 ◽  
Vol 3 ◽  
pp. 247054701985016 ◽  
Author(s):  
Lynn D. Selemon ◽  
Keith A. Young ◽  
Dianne A. Cruz ◽  
Douglas E. Williamson

Symptoms of posttraumatic stress disorder include hyperarousal, avoidance of trauma-related stimuli, re-experiencing of trauma, and mood changes. This review focuses on the frontal cortical areas that form crucial links in circuitry pertinent to posttraumatic stress disorder symptomatology: (1) the conditioned fear extinction circuit, (2) the salience circuit, and (3) the mood circuit. These frontal areas include the ventromedial prefrontal cortex (conditioned fear extinction), the dorsal anterior cingulate and insular cortices (salience), and the lateral orbitofrontal and subgenual cingulate cortices (mood). Frontal lobe structural abnormalities in posttraumatic stress disorder, including volumetric reductions in the cingulate cortices, impact all three circuits. Functional analyses of frontal cortices in posttraumatic stress disorder show abnormal activation in all three according to task demand and emotional valence. Network analyses reveal altered amygdalo-frontal connectivity and failure to suppress the default mode network during cognitive engagement. Spine shape alterations also have been detected in the medial orbitofrontal cortex in posttraumatic stress disorder postmortem brains, suggesting reduced synaptic plasticity. Importantly, frontal lobe abnormalities in posttraumatic stress disorder extend beyond emotion-related circuits to include the lateral prefrontal cortices that mediate executive functions. In conclusion, widespread frontal lobe dysfunction in posttraumatic stress disorder provides a neurobiologic basis for the core symptomatology of the disorder, as well as for executive function impairment.


2021 ◽  
Vol 53 (8S) ◽  
pp. 303-304
Author(s):  
Kevin M. Crombie ◽  
Anneliis Sartin-Tarm ◽  
Kyrie Sellnow ◽  
Rachel Ahrenholtz ◽  
Sierra Lee ◽  
...  

2011 ◽  
Vol 69 (6) ◽  
pp. 556-563 ◽  
Author(s):  
Seth D. Norrholm ◽  
Tanja Jovanovic ◽  
Ilana W. Olin ◽  
Lauren A. Sands ◽  
India Karapanou ◽  
...  

2017 ◽  
Vol 121 (5) ◽  
pp. 792-814 ◽  
Author(s):  
Auretta S. Kummar

Research in the neuroscience of mindfulness has grown rapidly in recent years. This includes empirical investigations into structural and functional changes in several brain regions—particularly, the hippocampus, the prefrontal cortex, and the amygdala—in association with the practice of mindfulness. Of interest to the current paper is that such brain regions are also implicated in empirical research focusing on fear extinction. While fear extinction has, therefore, been suggested as one of the possible mechanisms to underlie the positive effects of mindfulness, the conceptual links and research implications have lacked specific focus and detailed discussion in the literature. The purpose of this paper is, therefore, two-fold. First, this paper briefly reviews the extant literature on the neuropsychological mechanisms underlying mindfulness—particularly that, which has been found to be similarly implied in fear extinction—and hence, suggests future research directions based on its current state in the literature. Second, this paper explores the implications of this for fear-based psychopathologies, specifically for posttraumatic stress disorder (PTSD). Discussion from this paper suggests the idea of fear extinction as an underlying mechanism of mindfulness to be one that is still preliminary, yet promising; in turn, elucidating the need for further methodologically rigorous study to specifically determine fear extinction as a result of mindfulness, as well as to incorporate neuroimaging techniques in supporting the existing literature that have found preliminary support of mindfulness for PTSD.


2018 ◽  
Vol 120 (5) ◽  
pp. 2649-2653 ◽  
Author(s):  
Rodolfo Souza Faria ◽  
Álvaro Luiz Bianchim Bereta ◽  
Guilherme Henrique Teixeira Reis ◽  
Lourdes Bethania Braga Santos ◽  
Marcela Santos Gomes Pereira ◽  
...  

We investigated the relation between swimming exercise and fear memory extinction. Rats that performed regular swimming exercise over 6 wk underwent fear conditioning. Twenty-eight days later, they were submitted to extinction tests. Swimming rats had enhanced extinction process throughout the 5 days of the extinction test compared with sedentary rats. This suggests that the swimming exercise accelerated the process of aversive memory extinction, reducing the expression of conditioned fear behavior. These results encourage further studies addressing the anxiolytic effects of exercise, with potential implications for anxiety disorders such as posttraumatic stress disorder. NEW & NOTEWORTHY We have shown that rats that performed regular swimming exercise over 6 wk had enhanced extinction process compared with sedentary animals. The swimming exercise may accelerate the process of aversive memory extinction, reducing the expression of conditioned fear behavior.


2018 ◽  
Vol 83 (9) ◽  
pp. S21 ◽  
Author(s):  
Christine Rabinak ◽  
Craig Peters ◽  
Farrah Elrahal ◽  
Mohammed Milad ◽  
Sheila Rauch ◽  
...  

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