scholarly journals The Role of the Nucleus Reuniens in Regulating Contextual Conditioning with the Predator Odor TMT

2021 ◽  
Author(s):  
Laura C. Ornelas ◽  
Kalynn Van Voorhies ◽  
Joyce Besheer

Experiencing intrusive distressing memories of a traumatic event(s) is a prominent symptom profile for post-traumatic stress disorder (PTSD). Understanding the neurobiological mechanisms associated with this symptom profile can be invaluable for effective treatment for PTSD. Here, we investigated the functional role of the nucleus reuniens (RE), a midline thalamic in modulating stressor-related memory. Female Long Evans rats were implanted with a cannula aimed at the RE. The RE was pharmacologically inactivated via muscimol (0.5 mM) prior to exposure to the predator odor stressor trimethylthiazoline (TMT; synthetically derived fox feces component) or water (controls) in a distinct context with bedding material (Experiment 1) or no bedding (Experiment 2). To measure context reactivity, the index of the contextual memory, 2 weeks following exposure to TMT, rats were re-exposed to the TMT-paired context (in the absence of TMT). In Experiment 1, during context re-exposure (with bedding), inactivation of the RE had no effect on context reactivity. In Experiment 2, during context re-exposure (no bedding), rats previous exposed to TMT showed decreased immobility compared to controls, indicating reactivity to the context and likely related to increased exploration of the environment. Rats in the TMT group that received RE inactivation showed increased immobility relative to rats that received aCSF, suggesting that muscimol pre-treatment blunted context reactivity. In conclusion, recruitment of the RE in stressor-related contextual memory appears to be dependent on the contextual environment and whether the animal is able to engage in different stress coping strategies.

2019 ◽  
Vol 15 (3) ◽  
Author(s):  
Isabel Fernandez ◽  
Chiara Callerame

Survivors involved in natural or man-made disasters can develop a range of psychological problems including Post-Traumatic Stress Disorder (PTSD), depression, other forms of psychological distress, and a poor quality of life. Therefore, the principal focus of early psychological interventions, according to World Health Organization, is to provide a rapid and effective therapeutical approach like EMDR therapy. The EMDR approach enables the assimilation and integration of the various aspects of a traumatic experience at a somatic, sensorial, cognitive, behavioral and emotional level. In this article will be presented data of 47 patients collected after the partial collapse of Morandi bridge, in Genoa, in August 2018. Survivors were treated applying the Recent Traumatic Episode Protocol (R-TEP); in order to evaluate the effect of the traumatic event and to monitor the intervention outcome, the Impact of Event Scale- Revised (IES-R) was administered to each person pre and after EMDR treatment. Results show that regardless the number of sessions and the time elapsed after the disaster in which they were performed, EMDR significantly reduced participants’ IES-R scores from pre-treatment to posttreatment. Clinical implications and limits of the study will be discussed.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4701 ◽  
Author(s):  
Meghan D. Caulfield ◽  
Catherine E. Myers

Many individuals with posttraumatic stress disorder (PTSD) report experiencing frequent intrusive memories of the original traumatic event (e.g., flashbacks). These memories can be triggered by situations or stimuli that reflect aspects of the trauma and may reflect basic processes in learning and memory, such as generalization. It is possible that, through increased generalization, non-threatening stimuli that once evoked normal memories become associated with traumatic memories. Previous research has reported increased generalization in PTSD, but the role of visual discrimination processes has not been examined. To investigate visual discrimination in PTSD, 143 participants (Veterans and civilians) self-assessed for symptom severity were grouped according to the presence of severe PTSD symptoms (PTSS) vs. few/no symptoms (noPTSS). Participants were given a visual match-to-sample pattern separation task that varied trials by spatial separation (Low, Medium, High) and temporal delays (5, 10, 20, 30 s). Unexpectedly, the PTSS group demonstrated better discrimination performance than the noPTSS group at the most difficult spatial trials (Low spatial separation). Further assessment of accuracy and reaction time using diffusion drift modeling indicated that the better performance by the PTSS group on the hardest trials was not explained by slower reaction times, but rather a faster accumulation of evidence during decision making in conjunction with a reduced threshold, indicating a tendency in the PTSS group to decide quickly rather than waiting for additional evidence to support the decision. This result supports the need for future studies examining the precise role of discrimination and generalization in PTSD, and how these cognitive processes might contribute to expression and maintenance of PTSD symptoms.


BMJ Open ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. e058386
Author(s):  
Ferozkhan Jadhakhan ◽  
David Evans ◽  
Deborah Falla

IntroductionPost-traumatic stress symptoms (PTSS), pain and disability frequently co-occur following traumatic injuries. Although the coexistence of these symptoms is common, the relation between these symptoms and the impact on longer-term outcome remains poorly understood. This systematic review aims to determine the role of PTSS on the development of chronic pain and/or pain-related disability following musculoskeletal trauma.Methods/analysisThis protocol is developed and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Protocol. The review will include studies that recruited individuals aged ≥16 years sustaining any traumatic event that resulted in one or more musculoskeletal injuries and where a recognised measure for the presence of PTSS symptoms, pain and disability using either validated questionnaires or symptom checklists was employed. The following citation databases MEDLINE, PsycINFO, EMBASE, CINAHL, ZETOC, Web of Science, PubMed and Google Scholar, as well as reference lists from key journals and grey literature, will be searched from inception to 31 November 2021. Two independent reviewers will search, screen studies, extract data and assess risk of bias. The relationship of PTSS, pain and pain-related disability by injury type and severity will be estimated with 95% CI. If possible, study results will be pooled into a meta-analysis. However, if heterogeneity between studies is high, data analyses will be presented descriptively. The overall quality of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation guidelines.Ethics and disseminationEthical approval will not be required for this systematic review since only data from existing studies will be used. This review is expected to provide a better understanding of the factors associated with PTSS, pain and pain-related disability following musculoskeletal trauma, and help with the development of targeted therapeutic interventions. Results of this review will be disseminated in peer-reviewed publications and via national and international conferences.PROSPERO registration numberCRD42021285243.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Adele Brunetti ◽  
Francesca Macedonio ◽  
Giuseppe Barbieri ◽  
Enrico Drioli

Abstract The recent roadmap of SPIRE initiative includes the development of “new separation, extraction and pre-treatment technologies” as one of the “key actions” for boosting sustainability, enhancing the availability and quality of existing resources. Membrane condenser is an innovative technology that was recently investigated for the recovery of water vapor for waste gaseous streams, such as flue gas, biogas, cooling tower plumes, etc. Recently, it has been also proposed as pre-treatment unit for the reduction and control of contaminants in waste gaseous streams (SOx and NOx, VOCs, H2S, NH3, siloxanes, halides, particulates, organic pollutants). This perspective article reports recent progresses in the applications of the membrane condenser in the treatment of various gaseous streams for water recovery and contaminant control. After an overview of the operating principle, the membranes used, and the main results achieved, the work also proposes the role of this technology as pre-treatment stage to other separation technologies. The potentialities of the technology are also discussed aspiring to pave the way towards the development of an innovative technology where membrane condenser can cover a key role in redesigning the whole upgrading process.


2021 ◽  
Vol 22 (11) ◽  
pp. 5495
Author(s):  
Felipe Borges Almeida ◽  
Graziano Pinna ◽  
Helena Maria Tannhauser Barros

Under stressful conditions, the hypothalamic-pituitary-adrenal (HPA) axis acts to promote transitory physiological adaptations that are often resolved after the stressful stimulus is no longer present. In addition to corticosteroids (e.g., cortisol), the neurosteroid allopregnanolone (3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) participates in negative feedback mechanisms that restore homeostasis. Chronic, repeated exposure to stress impairs the responsivity of the HPA axis and dampens allopregnanolone levels, participating in the etiopathology of psychiatric disorders, such as major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). MDD and PTSD patients present abnormalities in the HPA axis regulation, such as altered cortisol levels or failure to suppress cortisol release in the dexamethasone suppression test. Herein, we review the neurophysiological role of allopregnanolone both as a potent and positive GABAergic neuromodulator but also in its capacity of inhibiting the HPA axis. The allopregnanolone function in the mechanisms that recapitulate stress-induced pathophysiology, including MDD and PTSD, and its potential as both a treatment target and as a biomarker for these disorders is discussed.


2021 ◽  
pp. 008124632199445
Author(s):  
Tammy-lee Pretorius

COVID-19 spread rapidly across the world, and by March 2020, the first case of COVID-19 was identified in South Africa. Lockdown-related measures such as restricted movement and isolation were implemented to contain the virus. Combined with these measures, factors such as economic decline, job losses, and food shortages can cause numerous mental health sequelae such as depression. Feelings of hopelessness and helplessness as well as cases of suicide have been reported around the world due to the pandemic and the associated feelings of anxiety and depression. The aims of this study were to investigate levels of hopelessness and depression in a sample of health care students. A random sample of students ( N = 174) enrolled in a health sciences programme at the University of the Western Cape completed the Beck Hopelessness Scale, the Center for Epidemiological Studies Depression Scale, and a three-item Resilience Scale. The results revealed high levels of hopelessness and depression compared to previously reported normative data for these scales. In addition, the indirect effects of hopelessness on depression were significant, demonstrating the mediating role of resilience in the hopelessness–depression relationship. These results highlight a call for universities to take proactive measures in providing students with free and easily accessible resources to help them cope and manage stress during a traumatic event. More importantly, at a national level, preventive measures should be implemented to strengthen resilience in young adults.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leonardo Santana Novaes ◽  
Letícia Morais Bueno-de-Camargo ◽  
Carolina Demarchi Munhoz

AbstractThe persistence of anxiety and the deficit of fear memory extinction are both phenomena related to the symptoms of a trauma-related disorder, such as post-traumatic stress disorder (PTSD). Recently we have shown that single acute restraint stress (2 h) in rats induces a late anxiety-related behavior (observed ten days after stress), whereas, in the present work, we found that the same stress impaired fear extinction in animals conditioned ten days after stress. Fourteen days of environmental enrichment (EE) prevented the deleterious effect of stress on fear memory extinction. Additionally, we observed that EE prevented the stress-induced increase in AMPA receptor GluA1 subunit phosphorylation in the hippocampus, but not in the basolateral amygdala complex and the frontal cortex, indicating a potential mechanism by which it exerts its protective effect against the stress-induced behavioral outcome.


Author(s):  
Susanne Fischer ◽  
Tabea Schumacher ◽  
Christine Knaevelsrud ◽  
Ulrike Ehlert ◽  
Sarah Schumacher

Abstract Background Less than half of all individuals with post-traumatic stress disorder (PTSD) remit spontaneously and a large proportion of those seeking treatment do not respond sufficiently. This suggests that there may be subgroups of individuals who are in need of augmentative or alternative treatments. One of the most frequent pathophysiological findings in PTSD is alterations in the hypothalamic–pituitary–adrenal (HPA) axis, including enhanced negative feedback sensitivity and attenuated peripheral cortisol. Given the role of the HPA axis in cognition, this pattern may contribute to PTSD symptoms and interfere with key processes of standard first-line treatments, such as trauma-focused cognitive behavioural therapy (TF-CBT). Methods This review provides a comprehensive summary of the current state of research regarding the role of HPA axis functioning in PTSD symptoms and treatment. Results Overall, there is preliminary evidence that hypocortisolaemia contributes to symptom manifestation in PTSD; that it predicts non-responses to TF-CBT; and that it is subject to change in parallel with positive treatment trajectories. Moreover, there is evidence that genetic and epigenetic alterations within the genes NR3C1 and FKBP5 are associated with this hypocortisolaemic pattern and that some of these alterations change as symptoms improve over the course of treatment. Conclusions Future research priorities include investigations into the role of the HPA axis in day-to-day symptom variation, the time scale in which biological changes in response to treatment occur, and the effects of sex. Furthermore, before conceiving augmentative or alternative treatments that target the described mechanisms, multilevel studies are warranted.


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