Amygdala Reward Neurons Form and Store Fear Extinction Memory

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c-fos expression in the amygdala:In vivo antisense modulation and role in anxiety

Summary 1. The amygdaloid complex is a key structure in mechanisms of fear and anxiety. Expression of the immediate-early gene c-fos has been reported in the central nucleus of the amygdala following various stressors, but the functional role of this phenomenon has remained unknown.2. c-fos expression was observed in the central nucleus when rats were subjected to a pharmacologically validated animal model of anxiety, the Vogel conflict test, but not after mere exposure to the test apparatus. Bilateral amygdala injection of a 15-mer phosphorothioate c-fos antisense oligodeoxynucleotide prior to testing blocked conflict-induced c-fos expression and had behavioral effects similar to those of established antianxiety drugs.3. Separate experiments determined that antisense treatment did not affect conflict behavior by acting on shock thresholds or drinking motivation.4. These findings provide evidence that neuronal activation and c-fos induction in the amygdala may be of importance for mechanisms of fear and anxiety.     

Beyond the landscape: Resistance modelling infers physical and behavioural gene flow barriers to a mobile carnivore across a metropolitan area

Urbanization affects key aspects of wildlife ecology. Dispersal in urban wildlife species may be impacted by geographical barriers but also by a species’ inherent behavioural variability. There are no functional connectivity analyses using continuous individual‐based sampling across an urban‐rural continuum that would allow a thorough assessment of the relative importance of physical and behavioural dispersal barriers. We used 16 microsatellite loci to genotype 374 red foxes (Vulpes vulpes) from the city of Berlin and surrounding rural regions in Brandenburg in order to study genetic structure and dispersal behaviour of a mobile carnivore across the urban‐rural landscape. We assessed functional connectivity by applying an individual‐based landscape genetic optimization procedure. Three commonly used genetic distance measures yielded different model selection results, with only the results of an eigenvector‐based multivariate analysis reasonably explaining genetic differentiation patterns. Genetic clustering methods and landscape resistance modelling supported the presence of an urban population with reduced dispersal across the city border. Artificial structures (railways, motorways) served as main dispersal corridors within the cityscape, yet urban foxes avoided densely built‐up areas. We show that despite their ubiquitous presence in urban areas, their mobility and behavioural plasticity, foxes were affected in their dispersal by anthropogenic presence. Distinguishing between man‐made structures and sites of human activity, rather than between natural and artificial structures, is thus essential for better understanding urban fox dispersal. This differentiation may also help to understand dispersal of other urban wildlife and to predict how behaviour can shape population genetic structure beyond physical barriers.     

Dog training as a violence prevention tool for at-risk adolescents

Abstract

Humane education programs often target at-risk children and seek to teach empathy and gentleness with animals, but few of these have been assessed. This prospective, longitudinal study examined the effects of “Teaching Love and Compassion” (TLC), a humane education program employing educational group discussions and dog training for seventh-grade, inner city youth in Los Angeles, California. The TLC program is offered to groups of 10 to 12 students during their three-week vacation at the year-round school. Students for the experimental and control groups were selected from the pool of those scoring below the 25th percentile in reading and mathematics. The study, conducted over a two-year period, assessed four successive sessions, comprising an experimental group of 41 children and a control group of 42 children. In morning sessions, the experimental group had discussions focusing on interpersonal issues and conflict management. In the afternoons they were taught the proper care and obedience training of shelter dogs. Pre-, post-, and follow-up tests, specially developed to accommodate the children's reading ability and scheduling constraints, were given to both the experimental and control groups to assess their knowledge of animal care, conflict management skills, attitudes toward self and others, and fear of dogs. Members of the experimental group increased their understanding of pet care and the needs of animals and retained this information more than did the control group for all four TLC sessions, both at post-testing (F=58.4, p=0.0001) and follow-up testing (F=18.9, p=0.0001). At post-testing, the experimental group showed a trend toward a decreased fear of dogs (F=3.6, p=0.062), that was significant at follow-up testing (F=4.2, p=0.019). For these children who are exposed to daily violence and aggression to people and animals, these modest changes were associated with the three-week intervention.     

Enhanced hippocampus‐dependent memory and reduced anxiety in mice over‐expressing human catalase in mitochondria

Oxidative stress (OS) and reactive oxygen species (ROS) play a modulatory role in synaptic plasticity and signaling pathways. Mitochondria (MT), a major source of ROS because of their involvement in energy metabolism, are important for brain function. MT‐generated ROS are proposed to be responsible for a significant proportion of OS and are associated with developmental abnormalities and aspects of cellular aging. The role of ROS and MT function in cognition of healthy individuals is relatively understudied. In this study, we characterized behavioral and cognitive performance of 5‐ to 6‐month‐old mice over‐expressing mitochondrial catalase (MCAT). MCAT mice showed enhancements in hippocampus‐dependent spatial learning and memory in the water maze and contextual fear conditioning, and reduced measures of anxiety in the elevated zero maze. Catalase activity was elevated in MCAT mice in all brain regions examined. Measures of oxidative stress (glutathione, protein carbonyl content, lipid peroxidation, and 8‐hydroxyguanine) did not significantly differ between the groups. The lack of differences in these markers of oxidative stress suggests that the differences observed in this study may be due to altered redox signaling. Catalase over‐expression might be sufficient to enhance cognition and reduce measures of anxiety even in the absence of alteration in levels of OS.     

牙科焦虑症治疗方法综述

牙科焦虑症主要是对疼痛的恐惧、对未知的恐惧、对机体受到伤害的恐惧等因素导致的焦虑症状。临床中80%的口腔疾病患者都对治疗心存恐惧,因此在很大程度上不能配合医生的治疗甚至逃避治疗。随着生活水平的不断提高,人们要求在舒适的心理环境中接受治疗,因此牙科焦虑症就成为口腔医护工作者必须面对的问题。治疗牙科焦虑症的方法主要分为行为学,药理学和有机放松法三个大类,在实际使用的过程当中往往是各种方法配合使用,而不是单一使用。随着人们研究的逐步深入,提出的具体治疗方法也越来越多,本文就牙科焦虑症目前所使用的治疗方法做详细的介绍及分类,帮助口腔医护工作人员理清治疗思路,为正确的诊断、干预和治疗牙科焦虑症提供治疗方法。