scholarly journals Role of Amygdala-Infralimbic Cortex Circuitry in Glucocorticoid-Induced Facilitation of Auditory Fear Memory Extinction

2021 ◽  
pp. 1-22
Author(s):  
Masoomeh Dadkhah ◽  
◽  
Abbas Ali Vafaei ◽  
Ali Rashidy-Pour ◽  
Parnia Trahomi ◽  
...  
Keyword(s):  
Critical Role ◽  
Fear Memory ◽  
Fear Extinction ◽  
Freezing Behavior ◽  
Extinction Training ◽  
Male Rats ◽  
Memory Extinction ◽  
The Right ◽  
Fear Expression

Purpose: The basolateral amygdala (BLA) and infralimbic area (IL) of medial prefrontal cortex (mPFC) are two inter-connected brain structures that mediate both fear memory expression and extinction. Besides the well-known role of the BLA in the acquisition and expression of fear memory, projections from IL to BLA inhibit fear expression and have a critical role in fear extinction. However, the details of IL-BLA interaction remain unclear. Here, we aimed to investigate the role of functional reciprocal interactions between BLA and IL in mediating fear memory extinction. Methods: Using lidocaine (LID), male rats underwent unilateral or bilateral inactivation of the BLA and then unilateral intra-IL infusion of CORT, prior to extinction training of auditory fear conditioning paradigm. Freezing behavior was reported as an index for the measurement of conditioned fear. Infusions were performed before the extinction training, allowing to examine the effects on fear expression and also further extinction memory. Experiments 1-3 investigated the effects of left or right infusion of CORT into IL, and LID unilaterally into BLA on fear memory extinction. Results: Results showed that intra-IL infusion of CORT in the right hemisphere reduced freezing behavior when administrated before the extinction training. Auditory fear memory extinction was impaired by asymmetric inactivation of BLA and CORT infusion in the right IL; however, the same effect was not observed with symmetric inactivation of BLA. Conclusion: It is concluded that that the IL-BLA neural circuit may provide additional evidence to contribution of this circuit in auditory fear extinction. This study demonstrate dissociable roles for right or left BLA in subserving the auditory fear extinction. Our finding also raise the possibility that left BLA-IL circuitry may contribute in mediating auditory fear memory extinction via underlying mechanisms, however further research is required.

scholarly journals Environmental enrichment prevents the late effect of acute stress-induced fear extinction deficit: the role of hippocampal AMPA-GluA1 phosphorylation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leonardo Santana Novaes ◽  
Letícia Morais Bueno-de-Camargo ◽  
Carolina Demarchi Munhoz
Keyword(s):  
Environmental Enrichment ◽  
Basolateral Amygdala ◽  
Acute Stress ◽  
Fear Memory ◽  
Fear Extinction ◽  
Post Traumatic Stress ◽  
Related Disorder ◽  
Memory Extinction ◽  
Post Traumatic

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.

scholarly journals Glycyrrhizin Treatment Facilitates Extinction of Conditioned Fear Responses After a Single Prolonged Stress Exposure in Rats

2018 ◽  
Vol 45 (6) ◽  
pp. 2529-2539 ◽  
Author(s):  
Shuhua Lai ◽  
Gangwei Wu ◽  
Zhixian Jiang
Keyword(s):  
Critical Role ◽  
Fear Memory ◽  
Fear Extinction ◽  
Chromosomal Protein ◽  
Single Prolonged Stress ◽  
Contextual Fear ◽  
Contextual Fear Memory ◽  
Memory Extinction ◽  
Prolonged Stress ◽  
Tlr4 Antagonist

Background/Aims: Impaired fear memory extinction is widely considered a key mechanism of post-traumatic stress disorder (PTSD). Recent studies have suggested that neuroinflammation after a single prolonged stress (SPS) exposure may play a critical role in the impaired fear memory extinction. Studies have shown that high mobility group box chromosomal protein 1 (HMGB-1) is critically involved in neuroinflammation. However, the role of HMGB-1 underlying the development of impairment of fear memory extinction is still not known. Methods: Thus, we examined the levels of HMGB-1 in the basolateral amygdala (BLA) following SPS using Western blot and evaluated the levels of microglia and astrocytes activation in the BLA after SPS using immunohistochemical staining. We then examined the effects of pre-SPS intra-BLA administration of glycyrrhizin, an HMGB1 inhibitor, or LPS-RS, a competitive TLR4 antagonist, on subsequent post-SPS fear extinction. Results: We found that SPS treatment prolonged the extinction of contextual fear memory after the SPS. The impairment of SPS-induced extinction of contextual fear memory was associated with increased HMGB1 and Toll-like receptor 4 (TLR4) levels in the BLA. Additionally, the impairment of SPS-induced extinction of contextual fear memory was associated with increased activation of microglia and astrocyte in the BLA. Intra-BLA administrations of glycyrrhizin (HMGB-1 inhibitor) or LPS-RS (TLR4 antagonist) can prevent the development of SPS-induced fear extinction impairment. Conclusion: Taken together, these results suggested that SPS treatment may not only produce short term effects on the HMGB1/TLR4-mediated pro-inflammation, but alter the response of microglia and astrocytes to the exposure to fear associated contextual stimuli.

scholarly journals Right Place at the Right Time: How Changes in Protocadherins Affect Synaptic Connections Contributing to the Etiology of Neurodevelopmental Disorders

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2711
Author(s):  
Maria Mancini ◽  
Silvia Bassani ◽  
Maria Passafaro
Keyword(s):  
Cell Adhesion ◽  
Neurodevelopmental Disorders ◽  
Synapse Formation ◽  
Large Fraction ◽  
Critical Role ◽  
Basic Research ◽  
Axon Pathfinding ◽  
Neurite Initiation ◽  
The Right

During brain development, neurons need to form the correct connections with one another in order to give rise to a functional neuronal circuitry. Mistakes during this process, leading to the formation of improper neuronal connectivity, can result in a number of brain abnormalities and impairments collectively referred to as neurodevelopmental disorders. Cell adhesion molecules (CAMs), present on the cell surface, take part in the neurodevelopmental process regulating migration and recognition of specific cells to form functional neuronal assemblies. Among CAMs, the members of the protocadherin (PCDH) group stand out because they are involved in cell adhesion, neurite initiation and outgrowth, axon pathfinding and fasciculation, and synapse formation and stabilization. Given the critical role of these macromolecules in the major neurodevelopmental processes, it is not surprising that clinical and basic research in the past two decades has identified several PCDH genes as responsible for a large fraction of neurodevelopmental disorders. In the present article, we review these findings with a focus on the non-clustered PCDH sub-group, discussing the proteins implicated in the main neurodevelopmental disorders.

Perspectives

1990 ◽  
Vol 15 (4) ◽  
pp. 3-10
Author(s):  
Jayanth R Varma ◽  
N Venkiteswaran
Keyword(s):  
Capital Market ◽  
Economic Activity ◽  
Critical Role ◽  
Regulatory Agencies ◽  
Recent Past ◽  
Positive Direction ◽  
Emerging Trends ◽  
The Government ◽  
The Right

The Indian capital market has shown signs of buoyancy and dynamism in the recent past. There is a very real need, therefore, to nurture and to give positive direction to the emerging trends in this sphere of economic activity. It is in this context that regulatory agencies have a critical role in providing the right kind of support to avoid bunching of issues as well as in protecting investors against manipulation by unscrupulous investors. Have Indian regulatory agencies risen to the occasion by formulating appropriate and adequate policies to facilitate the development of the capital markets in India? In this article, Varma and Venkiteswaran examine the role of Indian regulatory agencies and evaluate the methodology spelt out in the official guidelines for valuation of equity shares made public by the Government of India.

scholarly journals SUN-235 Deficient Fear Extinction in PRKAR1A-Defective Mice

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Margaret Keil ◽  
Enrica Paradiso ◽  
Rita S Keil ◽  
Maddalena Ugolini ◽  
Evan Harris ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fear Conditioning ◽  
Conditioned Fear ◽  
Critical Role ◽  
Fear Memory ◽  
Brain Regions ◽  
Fear Extinction ◽  
Carney Complex ◽  
Bdnf Gene ◽  
Extinction Learning

Abstract Background: The role of the cAMP/PKA signaling in molecular pathways involved in fear memory is well established: PKA is required for fear memory formation and is a constraint for fear extinction. Previously we reported that a Prkar1a heterozygote (HZ) mouse that was developed in our lab to investigate Carney complex (CNC), the disease caused by PRKAR1A mutations, showed brain region-specific increased PKA activity that was associated with anxiety-like behavioral phenotype and threat bias (Keil, 2010, 2013). We hypothesized that Prkar1a+/- (HZ) mice would have deficits in fear extinction behavior. Brain derived neurotrophic factor (BDNF) has a critical role in formation of fear memory and its transcription is regulated by PKA/CREB. A mouse model with down regulation of PKA provides an opportunity for the first time to investigate the effect of altered PKA signaling on fear conditioning and extinction. Method: Fear conditioning, fear extinction learning, and fear extinction recall were tested in adult male HZ and wild-type (WT) mice as follows: fear conditioning training followed 24hr later by extinction training (new context), then 24hr later by extinction recall training. Percentage of time freezing was used to assess conditioned fear response. We measured BDNF gene expression in brain regions after completion of extinction recall training. Results: As expected, fear conditioning (learning) behavior was similar in HZ and WT mice. However, HZ mice showed a significant deficit in the early phase of fear extinction learning compared to WT. There was no difference in extinction recall between genotypes. Alterations in BDNF gene expression in the prefrontal cortex and amygdala was associated with deficit in fear extinction. Conclusion: Mice with a downregulation of Prkar1a gene demonstrate intact fear conditioning but impaired fear extinction learning, consistent with prior studies that report that PKA inhibition is necessary to facilitate extinction learning. Prkar1a+/- mice provide a valuable model to investigate impaired fear extinction to identify mechanisms for therapeutic targets for anxiety and trauma-related disorders.

scholarly journals THE ROLE OF FINANCE IN OUR LIVES

2021 ◽  
pp. 30-34
Author(s):  
Shahbaz Khalid
Keyword(s):  
Financial Analysis ◽  
Critical Role ◽  
Investment Risk ◽  
Financial Success ◽  
Financial Forecasting ◽  
Daily Stress ◽  
Individual Resilience ◽  
The Right ◽  
High Level

The article presents a comprehensive economics and financial analysis that plays a critical role in all areas of life. It plays an important role in individual resilience. This study includes financial and economical planning factors, revenue analysis, investment risk and financial forecasting. It includes budgeting, spending and saving. Healthy finances simply emphasize many of the goals of my life because healthy investments keep my daily stress level low, allow me to focus on doing other things, and open up opportunities to move forward. In other words, having the right level of financial success is one of the factors I measure in my life. How your financial skills help you understand how much you earn, what your monthly expenses are, and how it helps you budget for that income. The concept is that the sensitivity of investment to investment should be measured taking into account the amount of solid assets that can be used as collateral. High-level firms in the capital had high levels of investment sensitivity during the pre-crisis crisis, while post-crisis firms were less sensitive to cash flow when investing. Finance involves managing finances. KEYWORDS: finance, importance of finance, learning finance, finance and accounting, life with finance, recognizing finance, roles of finance

The rhetoric of New Zealand's COVID-19 response

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Binh Bui ◽  
Olayinka Moses ◽  
John Dumay
Keyword(s):  
Critical Role ◽  
Decision Makers ◽  
Response Strategy ◽  
Content Type ◽  
Rhetorical Strategy ◽  
The Public ◽  
Government Documents ◽  
The Right ◽  
Public Policy Decisions

PurposeThe authors unpack the critical role of rhetoric in developing and justifying the New Zealand (NZ) government's coronavirus disease 2019 (COVID-19) lockdown strategy.Design/methodology/approachUsing Green's (2004) theory of rhetorical diffusion, the authors analysed government documents and media releases before, during and after the lockdown to reconstruct the government's rationale.FindingsThe blending of kairos (sense of urgency and “right” time to act), ethos (emphasis on “saving lives”), pathos (fear of disruption and death) and selective use of health-based logos (shrinking infection rates), prompted fast initial adoption of the lockdown. However, support for the rhetoric wavered post-lockdown as absence of robust logos became apparent to the public.Research limitations/implicationsThe authors implicate the role of rhetoric in decision-makers’ ability to successfully elicit support for a new practice under urgency and the right moment to act using emotionalisation and moralisation. The assessment of the NZ government's response strategy provides insights decision-makers could glean in developing policies to tame the virus.Practical implicationsThis study’s analysis demonstrates the unsustainability of rhetoric in the absence of reliable information.Originality/valueThe authors demonstrate the consequences of limited (intermittent) evidence and disregard for accounting/accountability data in public policy decisions under a rhetorical strategy.

scholarly journals Critical role of the right VLPFC in emotional regulation of social exclusion: a tDCS study

2018 ◽  
Vol 13 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Zhenhong He ◽  
Yiqin Lin ◽  
Lisheng Xia ◽  
Zhenli Liu ◽  
Dandan Zhang ◽  
...  
Keyword(s):  
Social Exclusion ◽  
Emotional Regulation ◽  
Critical Role ◽  
The Right
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