227 research outputs found

    Extinction and Retrieval + Extinction of Conditioned Fear Differentially Activate Medial Prefrontal Cortex and Amygdala in Rats

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    Pairing a previously neutral conditioned stimulus (CS; e.g., a tone) to an aversive unconditioned stimulus (US; e.g., a footshock) leads to associative learning such that the tone alone comes to elicit a conditioned response (e.g., freezing). We have previously shown that an extinction session that occurs within the reconsolidation window (termed retrieval+extinction) attenuates fear responding and prevents the return of fear in Pavlovian fear conditioning (Monfils et al., 2009). To date, the mechanisms that explain the different behavioral outcomes between standard extinction and retrieval+extinction remain poorly understood. Here we sought to examine the differential temporal engagement of specific neural systems by these 2 approaches using Arc catFISH (cellular compartment analysis of temporal activity using fluorescence in situ hybridization). Our results demonstrate that extinction and retrieval+extinction lead to differential patterns of expression, suggesting that they engage different networks. These findings provide insight into the neural mechanisms that allow extinction during reconsolidation to prevent the return of fear in rats

    Extinction, applied after retrieval of auditory fear memory, selectively increases zinc-finger protein 268 and phosphorylated ribosomal protein S6 expression in prefrontal cortex and lateral amygdala

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    Abstract Retrieval of consolidated memories induces a labile phase during which memory can be disrupted or updated through a reconsolidation process. A central component of behavioral updating during reconsolidation using a retrieval–extinction manipulation (Ret + Ext) is the synaptic removal of a calcium-permeable-α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor (CP-AMPARs) in the lateral amygdala—a metabotropic GluR1 receptor (mGluR1) dependent mechanism. In the present study, we investigate the effect of Ret + Ext on the expression of molecular markers that could play a role in the reconsolidation process. Specifically, we tested the effects of Ret + Ext on the global expression of zinc-finger 268 protein (Zif268), a marker previously found to be implicated in memory reconsolidation, to confirm its occurrence after retrieval (Ret) and Ret + Ext. We also evaluated the global expression of phosphorylated ribosomal protein S6 (rpS6P), here proposed as a marker of the mGluR1-mediated memory process induced by Ret + Ext. The expression of both markers (zif268, rpS6P) was assessed by immunolocalization in prelimbic cortex (PRL), infralimbic cortex (IL), ventral subdivision of the lateral amygdala (LA) and hippocampus CA1 (CA1) in fear-conditioned rats. Our results showed that retrieval and Ret + Ext, but not extinction alone, increased Zif268 expression in prefrontal cortex and lateral amygdala. Ret + Ext, but not retrieval, retrieval followed by context exposure or extinction alone, increased the expression of rpS6P in prefrontal cortex and LA. In summary, (i) Zif268 increased after retrieval confirming that reconsolidation is engaged in our conditions, (ii) Zif268 increased after Ret + Ext confirming that it does not simply reflect an extinction or reconsolidation disruption (Zif268 level of expression should be lower in both cases) and (iii) rpS6P increased after Ret + Ext, but not after extinction, suggesting, as expected, a potential mGluR1 mediated molecular mechanism specific for Ret + Ext. Together with the Zif268 increase, our results suggest that the Ret + Ext induced memory process is more similar to reconsolidation updating than extinction facilitation

    Deep-Reaching Global Ocean Overturning Circulation Generated by Surface Buoyancy Forcing

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    In contrast with the atmosphere, which is heated from below by solar radiation, the ocean is both heated and cooled from above. To drive a deep-reaching overturning circulation in this context, it is generally assumed that either intense interior mixing by winds and internal tides, or wind-driven upwelling is required; in their absence, the circulation is thought to collapse to a shallow surface cell. We demonstrate, using a primitive equation model with an idealized domain and no wind forcing, that the surface temperature forcing can in fact drive an interhemispheric overturning provided that there is an open channel unblocked in the zonal direction, such as in the Southern Ocean. With this geometry, rotating horizontal convection, in combination with asymmetric surface cooling between the north and south, drives a deep-reaching two-cell overturning circulation. The resulting vertical mid-depth stratification closely resembles that of the real ocean, suggesting that wind-driven pumping is not necessary to produce a deep-reaching overturning circulation, and that buoyancy forcing plays a more important role than is usually assumed

    Increasing phylogenetic stochasticity at high elevations on summits across a remote North American wilderness

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/1/ajb21328-sup-0002-AppendixS2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/2/ajb21328-sup-0003-AppendixS3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/3/ajb21328-sup-0004-AppendixS4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/4/ajb21328.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/5/ajb21328-sup-0009-AppendixS9.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/6/ajb21328-sup-0005-AppendixS5.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/7/ajb21328-sup-0007-AppendixS7.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/8/ajb21328-sup-0006-AppendixS6.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/9/ajb21328-sup-0008-AppendixS8.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/10/ajb21328_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150529/11/ajb21328-sup-0001-AppendixS1.pd

    Pitch perception and production in congenital amusia: evidence from Cantonese speakers

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    This study investigated pitch perception and production in speech and music in individuals with congenital amusia (a disorder of musical pitch processing) who are native speakers of Cantonese, a tone language with a highly complex tonal system. Sixteen Cantonese-speaking congenital amusics and 16 controls performed a set of lexical tone perception, production, singing, and psychophysical pitch threshold tasks. Their tone production accuracy and singing proficiency were subsequently judged by independent listeners, and subjected to acoustic analyses. Relative to controls, amusics showed impaired discrimination of lexical tones in both speech and non-speech conditions. They also received lower ratings for singing proficiency, producing larger pitch interval deviations and making more pitch interval errors compared to controls. Demonstrating higher pitch direction identification thresholds than controls for both speech syllables and piano tones, amusics nevertheless produced native lexical tones with comparable pitch heights/contours and intelligibility as controls. Significant correlations were found between pitch threshold and lexical tone perception, music perception and production, but not between lexical tone perception and production for amusics. These findings provide further evidence that congenital amusia is domain-general language-independent pitch-processing deficit that is associated with severely impaired music perception and production, mildly impaired speech perception, and largely intact speech production

    Trackly:A Customisable and Pictorial Self-Tracking App to Support Agency in Multiple Sclerosis Self-Care

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    Self-tracking is an important part of self-care. However, predefined self-tracking approaches can impede people's agency in managing their health. We investigated a customisable and pictorial self-tracking approach in multiple sclerosis self-management by implementing and conducting a field study of Trackly: a prototype app that supports people in defining and colouring pictorial trackers, such as body shapes. We found that participants utilised the elements of Trackly designed to support agentive behaviour: they defined personally meaningful tracking parameters in their own words, and particularly valued being able to flexibly colour in and make sense of their pictorial trackers. Having been able to support their individual self-care intentions with Trackly, participants reported a spectrum of interrelated experiences of agency, including a sense of ownership, identity, self-awareness, mindfulness, and control. Our findings demonstrate the importance of supporting people's individual needs and creative capacities to foster mindful and personally meaningful engagement with health and wellbeing data

    Anthropogenic Space Weather

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    Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release ex- periments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.Comment: 71 pages, 35 figure

    Use of satellite observations for operational oceanography: recent achievements and future prospects

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    The paper gives an overview of the development of satellite oceanography over the past five years focusing on the most relevant issues for operational oceanography. Satellites provide key essential variables to constrain ocean models and/or serve downstream applications. New and improved satellite data sets have been developed and have directly improved the quality of operational products. The status of the satellite constellation for the last five years was, however, not optimal. Review of future missions shows clear progress and new research and development missions with a potentially large impact for operational oceanography should be demonstrated. Improvement of data assimilation techniques and developing synergetic use of high resolution satellite observations are important future priorities

    Resolving the Evolutionary History of Campanula (Campanulaceae) in Western North America

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    Recent phylogenetic works have begun to address long-standing questions regarding the systematics of Campanula (Campanulaceae). Yet, aspects of the evolutionary history, particularly in northwestern North America, remain unresolved. Thus, our primary goal in this study was to infer the phylogenetic positions of northwestern Campanula species within the greater Campanuloideae tree. We combined new sequence data from 5 markers (atpB, rbcL, matK, and trnL-F regions of the chloroplast and the nuclear ITS) representing 12 species of Campanula with previously published datasets for worldwide campanuloids, allowing us to include approximately 75% of North American Campanuleae in a phylogenetic analysis of the Campanuloideae. Because all but one of North American Campanula species are nested within a single campanuloid subclade (the Rapunculus clade), we conducted a separate set of analyses focused specifically on this group. Our findings show that i) the campanuloids have colonized North America at least 6 times, 4 of which led to radiations, ii) all but one North American campanuloid are nested within the Rapunculus clade, iii) in northwestern North America, a C. piperi – C. lasiocarpa ancestor gave rise to a monophyletic Cordilleran clade that is sister to a clade containing C. rotundifolia, iv) within the Cordilleran clade, C. parryi var. parryi and C. parryi var. idahoensis exhibit a deep, species-level genetic divergence, and v) C. rotundifolia is genetically diverse across its range and polyphyletic. Potential causes of diversification and endemism in northwestern North America are discussed
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