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Contextual fear

Lars Marstaller, Hana Burianová, David C Reutens
Safety learning describes the ability to learn that certain cues predict the absence of a dangerous or threatening event. Although incidental observations of activity within the default mode network (DMN) during the processing of safety cues have been reported previously, there is as yet no evidence demonstrating that the DMN plays a functional rather than a corollary role in safety learning. Using functional magnetic resonance imaging and a Pavlovian fear conditioning and extinction paradigm, we investigated the neural correlates of danger and safety learning...
October 21, 2016: Human Brain Mapping
Isabel Vieira de Assis Lima, Alline Cristina de Campos, Paula Maria Quaglio Bellozi, Juliana Guimaraes Doria, Fabiola Mara Ribeiro, Marcio Flavio Dutra Moraes, Antonio Carlos Pinheiro de Oliveira
Temporal lobe epilepsy (TLE) is the most common form of epilepsy in adults. The pilocarpine (PILO) experimental model of TLE portrays behavioral and pathophysiological changes in rodents that are very similar to those found in humans with TLE. However, this model is associated with an unfortunate high mortality rate. Studies have shown that intrahippocampal injection of PILO, while having a much smaller mortality rate, induces status epilepticus (SE) that secondarily leads to TLE. To the best of our knowledge, the present study was the first to evaluate the cognitive and histological alterations 72h after intrahippocampal microinjection of PILO in C57BL/6 mice...
October 10, 2016: Epilepsy & Behavior: E&B
Brenna M Flannery, Donald A Bruun, Douglas J Rowland, Christopher N Banks, Adam T Austin, David L Kukis, Yonggang Li, Byron D Ford, Daniel J Tancredi, Jill L Silverman, Simon R Cherry, Pamela J Lein
BACKGROUND: Acute intoxication with organophosphorus (OP) cholinesterase inhibitors can trigger convulsions that progress to life-threatening status epilepticus. Survivors face long-term morbidity including mild-to-severe decline in memory. It is posited that neuroinflammation plays a key role in the pathogenesis of OP-induced neuropsychiatric deficits. Rigorous testing of this hypothesis requires preclinical models that recapitulate relevant phenotypic outcomes. Here, we describe a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) that exhibits persistent neuroinflammation and cognitive impairment...
October 12, 2016: Journal of Neuroinflammation
Naoki Matsuo
No abstract text is available yet for this article.
2016: Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica
Catherine Lau, Mark Hebert, Marc A Vani, Sue Walling, Shawn Hayley, Diane C Lagace, Jacqueline Blundell
Traumatic events contribute to a variety of neuropsychiatric disorders including post-traumatic stress disorder (PTSD). Identifying the neural mechanisms that affect the stress response may improve treatment for stress-related disorders. Neurogenesis, the production of neurons, occurs within the adult brain and disturbances in neurogenesis in the subgranular zone (SGZ) of the hippocampus have been linked to mood and anxiety disorders. Chronic stress models have mainly suggested correlations with stress reducing adult SGZ neurogenesis, whereas acute stress models and those with a naturalistic component that are also associated with long-lasting behavioral changes have produced inconsistent results...
October 7, 2016: Neuroscience
Claire Le Dorze, Pascale Gisquet-Verrier
Intrusive re-experiencing of a trauma is a core symptom in post-traumatic stress disorder (PTSD), and is often triggered by contextual cues associated with the event. It is not yet established if intrusive re-experiencing is the consequence of PTSD, or if it could contribute to the development of PTSD following a traumatic event. The present study (1) examined the impact of repeated brief re-exposures to trauma reminders on the strength of PTSD-like symptoms, as well as on their time-development and (2) investigated the reactivity over time to these cues in trauma resilient and vulnerable rats, defined on the basis of the PTSD-like symptoms they demonstrated...
October 4, 2016: Brain Research
Flurin Cathomas, Hannes Sigrist, Luca Schmid, Erich Seifritz, Martin Gassmann, Bernhard Bettler, Christopher R Pryce
Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain and is implicated in the pathophysiology of a number of neuropsychiatric disorders. The GABAB receptors are G-protein coupled receptors consisting of principle subunits and auxiliary potassium channel tetramerization domain (KCTD) subunits. The KCTD subunits 8, 12, 12b and 16 are cytosolic proteins that determine the kinetics of the GABAB receptor response. Previously, we demonstrated that Kctd12 null mutant mice (Kctd12(-/-)) exhibit increased auditory fear learning and that Kctd12(+/-) mice show altered circadian activity, as well as increased intrinsic excitability in hippocampal pyramidal neurons...
October 4, 2016: Behavioural Brain Research
Israel Liberzon, James L Abelson
Progress in clinical and affective neuroscience is redefining psychiatric illness as symptomatic expression of cellular/molecular dysfunctions in specific brain circuits. Post-traumatic stress disorder (PTSD) has been an exemplar of this progress, with improved understanding of neurobiological systems subserving fear learning, salience detection, and emotion regulation explaining much of its phenomenology and neurobiology. However, many features remain unexplained and a parsimonious model that more fully accounts for symptoms and the core neurobiology remains elusive...
October 5, 2016: Neuron
Marlene A Wilson, Jim R Fadel
Cholinergic activation regulates cognitive function, particularly long-term memory consolidation. This Review presents an overview of the anatomical, neurochemical, and pharmacological evidence supporting the cholinergic regulation of Pavlovian contextual and cue-conditioned fear learning and extinction. Basal forebrain cholinergic neurons provide inputs to neocortical regions and subcortical limbic structures such as the hippocampus and amygdala. Pharmacological manipulations of muscarinic and nicotinic receptors support the role of cholinergic processes in the amygdala, hippocampus, and prefrontal cortex in modulating the learning and extinction of contexts or cues associated with threat...
October 5, 2016: Journal of Neuroscience Research
Clare Dolman, Ian R Jones, Louise M Howard
BACKGROUND: Women with bipolar disorder are at increased risk of having a severe episode of illness associated with childbirth. AIMS: To explore the factors that influence the decision-making of women with bipolar disorder regarding pregnancy and childbirth. METHOD: Qualitative study with a purposive sample of women with bipolar disorder considering pregnancy, or currently or previously pregnant, supplemented by data from an online forum. Data were analysed using thematic analysis...
September 2016: BJPsych Open
Marna Eliana Sakalem, Thomas Seidenbecher, Mingyue Zhang, Roja Saffari, Mykola Kravchenko, Stephanie Wördemann, Kai Diederich, Jens C Schwamborn, Weiqi Zhang, Oliver Ambrée
It is well known that adult neurogenesis occurs in two distinct regions, the subgranular zone of the dentate gyrus and the subventricular zone along the walls of the lateral ventricles. Until now, the contribution of these newly born neurons to behavior and cognition is still uncertain. The current study tested the functional impacts of diminished hippocampal neurogenesis on emotional and cognitive functions in transgenic Gfap-tk mice. Our results showed that anxiety-related behavior evaluated both in the elevated plus maze as well as in the open field, social interaction in the sociability test, and spatial working memory in the spontaneous alternation test were not affected...
October 4, 2016: Hippocampus
Nicholas P Allan, Mary E Oglesby, Aubree Uhl, Norman B Schmidt
The hierarchical model of vulnerabilities to emotional distress contextualizes the relation between neuroticism and social anxiety as occurring indirectly through cognitive risk factors. In particular, inhibitory intolerance of uncertainty (IU; difficulty in uncertain circumstances), fear of negative evaluation (FNE; fear of being judged negatively), and anxiety sensitivity (AS) social concerns (fear of outwardly observable anxiety) are related to social anxiety. It is unclear whether these risk factors uniquely relate to social anxiety, and whether they account for the relations between neuroticism and social anxiety...
October 3, 2016: Cognitive Behaviour Therapy
Débora Raquel Soares Guedes Trigueiro, Sandra Aparecida de Almeida, Aline Aparecida Monroe, Gilka Paiva Oliveira Costa, Valéria Peixoto Bezerra, Jordana de Almeida Nogueira
OBJECTIVE: To graspthe AIDS social representations built by freedom-deprived women. METHOD: Descriptive study with a quali-quantitative approach that involved 174 convicted women in a women's prison in a capital city of the Brazilian northeastern region. Aword-association test was applied in October and November 2014, using AIDS as a stimulus. The corpuswas processed usingIramuteq software. Descending Hierarchical Classification and Correspondence Factor Analysis were applied...
July 2016: Revista da Escola de Enfermagem da U S P
Soyoung Rhee, Gregory W Kirschen, Yan Gu, Shaoyu Ge
The primary cilium, a sensory organelle, regulates cell proliferation and neuronal development of dentate granule cells in the hippocampus. However, its role in the function of mature dentate granule cells remains unknown. Here we specifically depleted and disrupted ciliary proteins IFT20 and Kif3A (respectively) in mature dentate granule cells and investigated hippocampus-dependent contextual memory and long-term plasticity at mossy fiber synapses. We found that depletion of IFT20 in these cells significantly impaired context-dependent fear-related memory...
September 28, 2016: Scientific Reports
L Luyten, N Schroyens, K Luyck, M S Fanselow, T Beckers
The excessive transfer of fear acquired for one particular context to similar situations has been implicated in the development and maintenance of anxiety disorders, such as post-traumatic stress disorder. Recent evidence suggests that glucose ingestion improves the retention of context conditioning. It has been speculated that glucose might exert that effect by ameliorating hippocampal functioning, and may hold promise as a therapeutic add-on in traumatized patients because improved retention of contextual fear could help to restrict its generalization...
2016: Translational Psychiatry
Sung-Hui Tseng, Feng-Hang Chang
PURPOSE: To identify the contextual factors that influence community participation in rehabilitation outpatients from the perspectives of patients and their service providers. METHOD: Five focus groups with rehabilitation outpatients (n = 22) and three focus groups with occupational and physical therapists (n = 17) were conducted. Two independent coders thematically analyzed the transcribed data. RESULTS: Patients and their providers identified three common personal factors (personal interests, personal values, and finances) and four major categories of environmental factors (products and technology; support and relationships; attitudes; and services, systems, and policies) that have great influence on patients' participation in the community...
September 26, 2016: Disability and Rehabilitation
Rie Ishikawa, Hotaka Fukushima, Paul W Frankland, Satoshi Kida
Forgetting of recent fear memory is promoted by treatment with memantine (MEM), which increases hippocampal neurogenesis. The approaches for treatment of post-traumatic stress disorder (PTSD) using rodent models have focused on the extinction and reconsolidation of recent, but not remote, memories. Here we show that, following prolonged re-exposure to the conditioning context, enhancers of hippocampal neurogenesis, including MEM, promote forgetting of remote contextual fear memory. However, these interventions are ineffective following shorter re-exposures...
2016: ELife
Abhishek Desai, Taeyeop Park, Jaquel Barnes, Karl Kevala, Huazhen Chen, Hee-Yong Kim
BACKGROUND: Adequate consumption of polyunsaturated fatty acids (PUFA) is vital for normal development and functioning of the central nervous system. The long-chain n-3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic acid are anti-inflammatory and neuroprotective in the models of central nervous system injury including traumatic brain injury (TBI). In the present study, we tested whether a higher brain DHA status in a mouse model on an adequate dietary α-linolenic acid (ALA) leads to reduced neuroinflammation and improved spontaneous recovery after TBI in comparison to a moderately lowered brain DHA status that can occur in humans...
2016: Journal of Neuroinflammation
Sarah Davies, Bridget Young, Peter Salmon
OBJECTIVE: This review aimed to synthesise qualitative research on problems in the parent-practitioner relationship in childhood cancer, to understand how these problems arise, how they are conceptualised and how they might be resolved. METHODS: A systematic search of five electronic databases identified 2863 articles. After screening, 81 full text papers were assessed for eligibility, and four were included in the review. Six further papers were identified through searching reference lists and citation tracking...
September 19, 2016: Psycho-oncology
Xinyu Xu, Chen Zheng, Nan Li, Hui Shen, Guolin Wang
Desflurane is one of the third generation inhaled anesthetics and can be used in obstetric and pediatric medicine. However, effects of exposure to desflurane on neonatal brain are largely unknown. In this work, 6-day-old C57BL/6J mice were exposed to 1MAC or 1.5MAC desflurane for 2h. When the mice were 28-day-old, the open-field, spontaneous alternation Y-maze and fear conditioning tests were performed to evaluate general activity, working memory and long term memory, respectively. Levels of NMDAR subunits NR1, NR2A, and NR2B expression in hippocampus were evaluated by western blot...
September 14, 2016: Behavioural Brain Research
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