bluuebunny/crossref_metadata_2025 huggingface dataset:
Nurses’ role in diabetic foot prevention and care; a review
Authors: Aalaa M , Malazy O Tabatabaei , Sanjari M , Peimani M , Mohajeri-Tehrani MR
Published: November 2012

Diabetes as one of Non-communicable diseases has allocated a large proportion of cost, time and human resources of health systems. Now, due to changes in lifestyle and industrial process, incidence of diabetes and its complications have been increased. Accordingly diabetic foot considered as a common complication of diabetes.

Nurses are health care providers who actively involved in prevention and early detection of diabetes and its complications. The nurses’ role could be in health care, health, community education, health systems management, patient care and improving the quality of life.

Diabetes Nurses play their educating role in the field of prevention of diabetic foot, foot care and preventing from foot injury. In care dimension, nurses responsible for early detection of any changes in skin and foot sensation, foot care, dressing and apply novel technology.

In the area of rehabilitation, help patient sufferings from diabetic foot ulcer or amputation, to have movement are diabetes nurse’s duties.

Consequently, nurses need to attend in special training to use the latest instructions of diabetic foot care in order that provides the effective services to facilitate promote diabetic patients health.
Reverse regulation of soluble receptor for advanced glycation end products and proinflammatory factor resistin and S100A12 in Kawasaki disease
Authors: Qi Yanqi , Gong Fangqi , Zhang Qing , Xie Chunhong , Wang Wei , Fu Songling
Published: November 2012

Introduction

Kawasaki disease (KD), an acute febrile disease, characterized by systemic vasculitis, predominantly affects infants and children under 5 years of age. Coronary artery lesions (CALs) are its most critical complication, and the etiology remains unknown yet. In order to explore the value of resistin, S100A12 and soluble receptor for advanced glycation end products (sRAGE) in the pathophysiology of KD, we studied the serum levels of resistin, S100A12 and sRAGE in different stages of KD.

Methods

Serum levels of resistin, S100A12 and sRAGE were measured by enzyme-linked immunosorbent assay (ELISA) method in 15 healthy children and 40 KD patients at acute, afebrile and subacute stage.

Results

The resistin and S100A12 levels, including the ratio of resistin to sRAGE and S100A12 to sRAGE increased significantly in the acute stage, and decreased progressively in the afebrile and subacute stage. However, the sRAGE levels decreased significantly in the acute stage, and increased progressively in the afebrile and subacute stage. In the acute, afebrile and subacute stage, the resistin levels were higher in intravenous immunoglobulin (IVIG) non-responders (0.64 ± 0.30, 0.48 ± 0.35, 0.28 ± 0.19, × 102 ng/ml) than in IVIG responders (0.35 ± 0.24, 0.21 ± 0.19, 0.12 ± 0.05, × 102 ng/ml). In the acute and subacute stage, the S100A12 levels were higher in IVIG non-responders (7.92 ± 2.61, 4.98 ± 4.75, × 102 ng/ml) than in IVIG responders (5.05 ± 3.22, 2.35 ± 2.26, × 102 ng/ml). In the afebrile and subacute stage, the sRAGE levels were lower in IVIG non-responders (3.51 ± 2.64, 3.65 ± 3.27, × 102 pg/ml) than in IVIG responders (6.00 ± 2.78, 7.19 ± 2.88, × 102 pg/ml). The resistin levels were positively correlated with S100A12 levels. The sRAGE levels were negatively related with S100A12 and resistin levels.

Conclusions

Resistin, S100A12 and sRAGE are involved in the pathophysiology of KD.
APRIL, a proliferation-inducing ligand, as a potential marker of lupus nephritis
Authors: Treamtrakanpon Worapot , Tantivitayakul Pornpen , Benjachat Thitima , Somparn Poorichaya , Kittikowit Wipawee , Eiam-ong Somchai , Leelahavanichkul Asada , Hirankarn Nattiya , Avihingsanon Yingyos
Published: November 2012

Introduction

BLyS and APRIL are cytokines from the tumor necrosis factor family which play an important role in systemic lupus erythematosus (SLE). Previous works suggested an association between both molecules and SLE disease activity although their correlation with lupus nephritis is not known. We therefore assessed serum BLyS and APRIL in active lupus nephritis patients.

Methods

Serum samples from active lupus nephritis and at 6 months post-treatment were obtained. Serum levels of BLyS and APRIL (n = 47) as well as renal mRNA expression were measured. Serum levels of both molecules and clinical data (n = 27) were available at 6 months follow-up. All biopsy-proven lupus nephritis patients were treated with similar immunosuppressive drugs.

Results

Serum levels of APRIL were associated with proteinuria (Rs = 0.44, P value < 0.01) and degree of histological activity (Rs = 0.34; P value < 0.05) whereas BLyS levels were associated with complement levels (Rs = 0.46; P value < 0.01) and dosage of immunosuppressant. Interestingly, serum APRIL as well as its intrarenal mRNA levels were associated with resistance to treatment. From the receiver operating characteristic (ROC) analysis, high levels (> 4 ng/mL) of serum APRIL predicted treatment failure with a positive predictive value of 93 percent.

Conclusion

APRIL could be a potential biomarker for predicting difficult-to-treat cases of lupus nephritis.
Severe hyperkalemia requiring hospitalization: predictors of mortality
Authors: An Jung Nam , Lee Jung Pyo , Jeon Hee Jung , Kim Do Hyoung , Oh Yun Kyu , Kim Yon Su , Lim Chun Soo
Published: November 2012

Introduction

Severe hyperkalemia, with potassium (K+) levels ≥ 6.5 mEq/L, is a potentially life-threatening electrolyte imbalance. For prompt and effective treatment, it is important to know its risk factors, clinical manifestations, and predictors of mortality.

Methods

An observational cohort study was performed at 2 medical centers. A total of 923 consecutive Korean patients were analyzed. All were 19 years of age or older and were hospitalized with severe hyperkalemia between August 2007 and July 2010; the diagnosis of severe hyperkalemia was made either at the time of admission to the hospital or during the period of hospitalization. Demographic and baseline clinical characteristics at the time of hyperkalemia diagnosis were assessed, and clinical outcomes such as in-hospital mortality were reviewed, using the institutions' electronic medical record systems.

Results

Chronic kidney disease (CKD) was the most common underlying medical condition, and the most common precipitating factor of hyperkalemia was metabolic acidosis. Emergent admission was indicated in 68.6% of patients, 36.7% had electrocardiogram findings typical of hyperkalemia, 24.5% had multi-organ failure (MOF) at the time of hyperkalemia diagnosis, and 20.3% were diagnosed with severe hyperkalemia at the time of cardiac arrest. The in-hospital mortality rate was 30.7%; the rate was strongly correlated with the difference between serum K+ levels at admission and at their highest point, and with severe medical conditions such as malignancy, infection, and bleeding. Furthermore, a higher in-hospital mortality rate was significantly associated with the presence of cardiac arrest and/or MOF at the time of diagnosis, emergent admission, and intensive care unit treatment during hospitalization. More importantly, acute kidney injury (AKI) in patients with normal baseline renal function was a strong predictor of mortality, compared with AKI superimposed on CKD.

Conclusions

Severe hyperkalemia occurs in various medical conditions; the precipitating factors are similarly diverse. The mortality rate is especially high in patients with severe underlying disease, coexisting medical conditions, and those with normal baseline renal function.
The Cold Model of Structure
Authors: Kittler Friedrich , Weinberger Christoph
Published: November 2012

The following interview with Friedrich Kittler, conducted by Christoph Weinberger in July 2007, is a passionate and instructive tour de force of pithy sound bites in which Kittler looks back on his work and criticizes alternate approaches to media.
Of States and Their Terrorists
Authors: Kittler Friedrich
Published: November 2012

This lecture, presented by Friedrich Kittler in 2002 as part of the Mosse Lecture Series at Humboldt University (Berlin), explores in a sequence of short historical vignettes the thesis that power systems such as the old British and the new American empires produce their own, system-specific enemies. In each case the technological environment provides the basis for the struggle between “states” and their “terrorists,” and the success of either party will depend on the degree to which they are able to adapt to and/or mobilize that environment. In addition, Kittler offers a philosophically informed genealogy of the “nomadic” state enemy, arguing that a basic dynamic of the escalating showdown is the increasingly invasive securing of natural resources.
Hunting a Whale of a State: Kittler and His Terrorists
Authors: Winthrop-Young Geoffrey
Published: November 2012

This essay is a companion piece to Friedrich Kittler's lecture “Of States and Their Terrorists.” It provides additional background, especially for Kittler's discussion of the German Red Army Faction (RAF ), and discusses the various sources (from Friedrich Nietzsche to Carl Schmitt) that inform Kittler's broader historical survey of technology and enmity.
In the Wake of the Odyssey
Authors: Kittler Friedrich
Published: November 2012

Friedrich Kittler's lecture, given in 2007 as part of the series of Mosse-Lectures, follows the recursions of Homer's Odyssey from its original transcription, coinciding with the invention of the Greek alphabet, through history. The stages of this include Virgil's Aeneid, Dante Alighieri's Divine Comedy, Jean-Luc Godard's Le mèpris, and Stanley Kubrick's 2001: A Space Odyssey. Kittler is concerned with the linkage of poetry, music, and sex from the Greeks to media- and computer-driven modernity.
Cloud Control, or the Network as Medium
Authors: Franklin Seb
Published: November 2012

Cloud computing is an increasingly commonplace term today, used to describe the relocation of hardware resources, programs, and data from individual, local machines to a network accessible from a variety of platforms and devices. In unpicking the complex cultural logic that cloud computing emblematizes, this essay analyzes the connections between the interrelated histories of cybernetics, computing, and distributed networks and the emerging economic models that ubiquitous networked computing facilitates.
The differentiation and movement of presomitic mesoderm progenitor cells are controlled by Mesogenin 1
Authors: Fior Rita , Maxwell Adrienne A. , Ma Taylur P. , Vezzaro Annalisa , Moens Cecilia B. , Amacher Sharon L. , Lewis Julian , Saúde Leonor
Published: November 2012

Somites are formed from the presomitic mesoderm (PSM) and give rise to the axial skeleton and skeletal muscles. The PSM is dynamic; somites are generated at the anterior end, while the posterior end is continually renewed with new cells entering from the tailbud progenitor region. Which genes control the conversion of tailbud progenitors into PSM and how is this process coordinated with cell movement? Using loss- and gain-of-function experiments and heat-shock transgenics we show in zebrafish that the transcription factor Mesogenin 1 (Msgn1), acting with Spadetail (Spt), has a central role. Msgn1 allows progression of the PSM differentiation program by switching off the progenitor maintenance genes ntl, wnt3a, wnt8 and fgf8 in the future PSM cells as they exit from the tailbud, and subsequently induces expression of PSM markers such as tbx24. msgn1 is itself positively regulated by Ntl/Wnt/Fgf, creating a negative-feedback loop that might be crucial to regulate homeostasis of the progenitor population until somitogenesis ends. Msgn1 drives not only the changes in gene expression in the nascent PSM cells but also the movements by which they stream out of the tailbud into the PSM. Loss of Msgn1 reduces the flux of cells out of the tailbud, producing smaller somites and an enlarged tailbud, and, by delaying exhaustion of the progenitor population, results in supernumerary tail somites. Through its combined effects on gene expression and cell movement, Msgn1 (with Spt) plays a key role both in genesis of the paraxial mesoderm and in maintenance of the progenitor population from which it derives.
Regulation of retinal interneuron subtype identity by theIroquoishomeobox geneIrx6
Authors: Star Erin N. , Zhu Minyan , Shi Zhiwei , Liu Haiquan , Pashmforoush Mohammad , Sauve Yves , Bruneau Benoit G. , Chow Robert L.
Published: November 2012

Interneuronal subtype diversity lies at the heart of the distinct molecular properties and synaptic connections that shape the formation of the neuronal circuits that are necessary for the complex spatial and temporal processing of sensory information. Here, we investigate the role of Irx6, a member of the Iroquois homeodomain transcription factor family, in regulating the development of retinal bipolar interneurons. Using a knock-in reporter approach, we show that, in the mouse retina, Irx6 is expressed in type 2 and 3a OFF bipolar interneurons and is required for the expression of cell type-specific markers in these cells, likely through direct transcriptional regulation. In Irx6 mutant mice, presumptive type 3a bipolar cells exhibit an expansion of their axonal projection domain to the entire OFF region of the inner plexiform layer, and adopt molecular features of both type 2 and 3a bipolar cells, highlighted by the ectopic upregulation of neurokinin 3 receptor (Nk3r) and Vsx1. These findings reveal Irx6 as a key regulator of type 3a bipolar cell identity that prevents these cells from adopting characteristic features of type 2 bipolar cells. Analysis of the Irx6;Vsx1 double null retina suggests that the terminal differentiation of type 2 bipolar cells is dependent on the combined expression of the transcription factors Irx6 and Vsx1, but also points to the existence of Irx6;Vsx1-independent mechanisms in regulating OFF bipolar subtype-specific gene expression. This work provides insight into the generation of neuronal subtypes by revealing a mechanism in which opposing, yet interdependent, transcription factors regulate subtype identity.
Emergence of embryonic pattern through contact inhibition of locomotion
Authors: Davis John R. , Huang Chieh-Yin , Zanet Jennifer , Harrison Sam , Rosten Edward , Cox Susan , Soong Daniel Y. , Dunn Graham A. , Stramer Brian M.
Published: November 2012

The pioneering cell biologist Michael Abercrombie first described the process of contact inhibition of locomotion more than 50 years ago when migrating fibroblasts were observed to rapidly change direction and migrate away upon collision. Since then, we have gleaned little understanding of how contact inhibition is regulated and only lately observed its occurrence in vivo. We recently revealed that Drosophila macrophages (haemocytes) require contact inhibition for their uniform embryonic dispersal. Here, to investigate the role that contact inhibition plays in the patterning of haemocyte movements, we have mathematically analysed and simulated their contact repulsion dynamics. Our data reveal that the final pattern of haemocyte distribution, and the details and timing of its formation, can be explained by contact inhibition dynamics within the geometry of the Drosophila embryo. This has implications for morphogenesis in general as it suggests that patterns can emerge, irrespective of external cues, when cells interact through simple rules of contact repulsion.
Residual body removal during spermatogenesis in C. elegans requires genes that mediate cell corpse clearance
Authors: Huang Jie , Wang Haibin , Chen Yingyu , Wang Xiaochen , Zhang Hong
Published: November 2012

Generation of spermatozoa involves segregation of most of the cytoplasm into residual bodies, which are detached from spermatids and eliminated in mammals. However, the molecular and cellular mechanism underlying the removal of residual bodies remains largely unknown. Here, we demonstrate that during C. elegans spermatogenesis residual bodies are engulfed and degraded by gonadal sheath cells, a process that uses the same set of genes underlying apoptotic cell removal. The two partially redundant engulfment pathways that clear cell corpses also mediate phagocytosis of residual bodies, possibly by recognizing the ‘eat me’ signal phosphatidylserine exposed on the surface. The residual body-containing phagosome undergoes a maturation process involving sequential steps including dynamic coating with PtdIns(3)P and association of RAB small GTPases. The genetic hierarchy of residual body removal in hermaphrodites is similar to that of cell corpse clearance, but male residual body removal involves a distinct hierarchy, with differential use of the engulfment genes. Efficient removal of residual bodies regulates the number of spermatids and effective transfer of spermatids during male matings. Our results indicate that a similar molecular mechanism is employed for the removal of residual bodies and apoptotic cell corpses in C. elegans.
Identification of small RNAs in Mycobacterium smegmatis using heterologous Hfq
Authors: Li Sai-Kam , Ng Patrick Kwok-Shing , Qin Hao , Lau Jeffrey Kwan-Yiu , Lau Jonathan Pak-Yuen , Tsui Stephen Kwok-Wing , Chan Ting-Fung , Lau Terrence Chi-Kong
Published: November 2012

Gene regulation by small RNAs (sRNAs) has been extensively studied in various bacteria. However, the presence and roles of sRNAs in mycobacteria remain largely unclear. Immunoprecipitation of RNA chaperone Hfq to enrich for sRNAs is one of the effective methods to isolate sRNAs. However, the lack of an identified mycobacterial hfq restricts the feasibility of this approach. We developed a novel method that takes advantage of the conserved inherent sRNAs-binding capability of heterologous Hfq from Escherichia coli to enrich sRNAs from Mycobacterium smegmatis, a model organism for studying Mycobacterium tuberculosis. We validated 12 trans-encoded and 12 cis-encoded novel sRNAs in M. smegmatis. Many of these sRNAs are differentially expressed at exponential phase compared with stationary phase, suggesting that sRNAs are involved in the growth of mycobacteria. Intriguingly, five of the cis-encoded novel sRNAs target known transposases. Phylogenetic conservation analysis shows that these sRNAs are pathogenicity dependent. We believe that our findings will serve as an important reference for future analysis of sRNAs regulation in mycobacteria and will contribute significantly to the development of sRNAs prediction programs. Moreover, this novel method of using heterologous Hfq for sRNAs enrichment can be of general use for the discovery of bacterial sRNAs in which no endogenous Hfq is identified.
Base-2 Expansions for Linearizing Products of Functions of Discrete Variables
Authors: Adams Warren P. , Henry Stephen M.
Published: November 2012

This paper presents an approach for representing functions of discrete variables, and their products, using logarithmic numbers of binary variables. Given a univariate function whose domain consists of n distinct values, it begins by employing a base-2 expansion to express the function in terms of the ceiling of log2n binary and n continuous variables, using linear restrictions to equate the functional values with the possible binary realizations. The representation of the product of such a function with a nonnegative variable is handled via an appropriate scaling of the linear restrictions. Products of m functions are treated in an inductive manner from i = 2 to m, where each step i uses such a scaling to express the product of function i and a nonnegative variable denoting a translated version of the product of functions 1 through i − 1 as a newly defined variable. The resulting representations, both in terms of one function and many, are important for reformulating general discrete variables as binary, and also for linearizing mixed-integer generalized geometric and discrete nonlinear programs, where it is desired to economize on the number of binary variables. The approach provides insight into, improves upon, and subsumes related linearization methods for products of functions of discrete variables.
The Bin Packing Problem with Precedence Constraints
Authors: Dell'Amico Mauro , Díaz José Carlos Díaz , Iori Manuel
Published: November 2012

Given a set of identical capacitated bins, a set of weighted items, and a set of precedences among such items, we are interested in determining the minimum number of bins that can accommodate all items and can be ordered in such a way that all precedences are satisfied. The problem, denoted as the bin packing problem with precedence constraints (BPP-P), has a very intriguing combinatorial structure and models many assembly and scheduling issues.

According to our knowledge, the BPP-P has received little attention in the literature, and in this paper we address it for the first time with exact solution methods. In particular, we develop reduction criteria, a large set of lower bounds, a variable neighborhood search upper bounding technique, and a branch-and-bound algorithm. We show the effectiveness of the proposed algorithms by means of extensive computational tests on benchmark instances and comparison with standard integer linear programming techniques.
Inverse Optimization: A New Perspective on the Black-Litterman Model
Authors: Bertsimas Dimitris , Gupta Vishal , Paschalidis Ioannis Ch.
Published: November 2012

The Black-Litterman (BL) model is a widely used asset allocation model in the financial industry. In this paper, we provide a new perspective. The key insight is to replace the statistical framework in the original approach with ideas from inverse optimization. This insight allows us to significantly expand the scope and applicability of the BL model. We provide a richer formulation that, unlike the original model, is flexible enough to incorporate investor information on volatility and market dynamics. Equally importantly, our approach allows us to move beyond the traditional mean-variance paradigm of the original model and construct “BL”-type estimators for more general notions of risk such as coherent risk measures. Computationally, we introduce and study two new “BL”-type estimators and their corresponding portfolios: a mean variance inverse optimization (MV-IO) portfolio and a robust mean variance inverse optimization (RMV-IO) portfolio. These two approaches are motivated by ideas from arbitrage pricing theory and volatility uncertainty. Using numerical simulation and historical backtesting, we show that both methods often demonstrate a better risk-reward trade-off than their BL counterparts and are more robust to incorrect investor views.
Nostalgia and Austerity, or, the never-ending dream of excess
Authors: Abbinnett Ross
Published: November 2012

The article is an attempt to examine the transformation of the neo-liberal ideology of consumption that has taken place since the onset of the global recession in 2008. The first section is an examination of Karl Marx's account of the antagonisms inherent in classical economic theories
of happiness, desire and prosperity, and how these have been intensified in the neo-liberal culture of consumption. The second section analyses the present conditions of class and identity formation that the UK Conservative Party has called ‘Broken Britain’. Specifically, I will
look at the relationship between the culture of ‘chance’, as it has crystallized into the discursive and aesthetic figure of ‘the underclass’, and the forms of ressentiment that are its ideological counterpart. The final section will examine the significance of this
configuration of the prudent and the profligate, the decent and the obscene, for the possibility of social and political change.
Precarious objects, precarious lives: Grounded aesthetics in poverty contexts
Authors: Lunghi Carla , Trasforini Maria Antonietta
Published: November 2012

This article will present and discuss results from a research study on aesthetics and poverty, recently carried out in Milan (Italy). Beauty, as a quality usually connected with art objects and tied to property and wealth, has been investigated in the ‘unusual’ context of
economic poverty, where ownership of objects is precarious or indeed non-existent. Using ethnographic observation and instruments of visual culture (photos), the research investigated the meanings of particular daily objects (i.e. pictures, clothes, religious images, etc.) displayed during
meetings with a sample of Italian and immigrant people, living in indigent conditions. The results suggest a critical review of P. Bourdieu’s theory on aesthetics and on taste as distinction practice, focusing instead on the ethical and relational dimensions of a grounded aesthetics.
As anthropology and material culture studies suggest, the aesthetic object acts in people’s lives as a polysemic item, contiguous with usefulness, rituality, relation. At he crossroads of the aesthetics of existence (Foucault) and daily practices (De Certeau), certain objects considered
beautiful become containers of affection, tools for public representation of the self, personal narrative and memories, displaying a practical and emotional control of a present difficult daily life.
Protest and video activism
Authors: Chanan Michael
Published: November 2012

Almost every one of the popular protest movements that have sprung up in the past couple of years in different parts of the world has taken to the Internet in a big way to organize and express itself. Indeed activists have proved extraordinarily adept in the use of the social media.
There is a paradox in the way that growing numbers of people are using the products of consumerism to try and combat the power of the same global corporate capitalism that sells them these very tools and instruments of free counter-cultural production to begin with. This paradox has a history
that this article brings back to mind, because one of the things about capitalism is that it not only creates the technologies employed in the mass media, but it cannot resist making consumer versions of the same gear – it is a simple question of maximizing the opportunities for consumption
and profits – and the consequences are often contradictory.
Popular culture and anti-austerity protest
Authors: Bramall Rebecca
Published: November 2012

The prevailing description of our times as an ‘age of austerity’ has hardened into an axiom with extraordinary rapidity. Focusing on contemporary popular and consumer culture in Britain, this article makes a contribution to the task of subjecting the discourse of ‘austerity’
to the consideration it properly demands. I identify and interrogate the meanings that ‘austerity’ has in contemporary culture, and recall the contingency of the processes through which these meanings have been consolidated,a task that is all the more urgent, I suggest, when it
feels like one prevailing signification has already ‘won out’. The article is organized around the discussion of three dominant meanings of austerity: austerity as ‘responsible politics’, deficit reduction and coalition government policy; austerity as the ‘other’
that defines left-political struggle; and austerity as ‘austerity chic’. The latter points to a conception of austerity as object of desire, an element that I develop and use to question the currently dominant critical position in left-cultural politics, the position of being ‘anti-aust
rity’.
Rab8 Modulates Metabotropic Glutamate Receptor Subtype 1 Intracellular Trafficking and Signaling in a Protein Kinase C-Dependent Manner
Authors: Esseltine Jessica L. , Ribeiro Fabiola M. , Ferguson Stephen S. G.
Published: November 2012

Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors (GPCRs) that are activated by glutamate, the primary excitatory neurotransmitter in the CNS. Alterations in glutamate receptor signaling are implicated in neuropathologies such as Alzheimer's disease, ischemia, and Huntington's disease among others. Group 1 mGluRs (mGluR1 and mGluR5) are primarily coupled to Gαq/11leading to the activation of phospholipase C and the formation of diacylglycerol and inositol 1,4,5-trisphosphate, which results in the release of intracellular calcium stores and protein kinase C (PKC) activation. Desensitization, endocytosis, and recycling are major mechanisms of GPCR regulation, and the intracellular trafficking of GPCRs is linked to the Rab family of small G proteins. Rab8 is a small GTPase that is specifically involved in the regulation of secretory/recycling vesicles, modulation of the actin cytoskeleton, and cell polarity. Rab8 has been shown to regulate the synaptic delivery of AMPA receptors during long-term potentiation and during constitutive receptor recycling. We show here that Rab8 interacts with the C-terminal tail of mGluR1a in an agonist-dependent manner and plays a role in regulating of mGluR1a signaling and intracellular trafficking in human embryonic kidney 293 cells. Specifically, Rab8 expression attenuates mGluR1a-mediated inositol phosphate formation and calcium release from mouse neurons in a PKC-dependent manner, while increasing cell surface mGluR1a expression via decreased receptor endocytosis. These experiments provide us with an understanding of the role Rabs play in coordinated regulation of mGluR1a and how this impacts mGluR1a signaling.
The CB1Cannabinoid Receptor Drives Corticospinal Motor Neuron Differentiation through the Ctip2/Satb2 Transcriptional Regulation Axis
Authors: Díaz-Alonso Javier , Aguado Tania , Wu Chia-Shan , Palazuelos Javier , Hofmann Clementine , Garcez Patricia , Guillemot François , Lu Hui-Chen , Lutz Beat , Guzmán Manuel , Galve-Roperh Ismael
Published: November 2012

The generation and specification of pyramidal neuron subpopulations during development relies on a complex network of transcription factors. The CB1cannabinoid receptor is the major molecular target of endocannabinoids and marijuana active compounds. This receptor has been shown to influence neural progenitor proliferation and axonal growth, but its involvement in neuronal differentiation and the functional impact in the adulthood caused by altering its signaling during brain development are not known. Here we show that the CB1receptor, by preventing Satb2 (special AT-rich binding protein 2)-mediated repression, increased Ctip2 (COUP-TF interacting protein 2) promoter activity, and Ctip2-positive neuron generation. Unbalanced neurogenic fate determination found in completeCB1−/−mice and in glutamatergic neuron-specificNex–CB1−/−mice induced overt alterations in corticospinal motor neuron generation and subcerebral connectivity, thereby resulting in an impairment of skilled motor function in adult mice. Likewise, genetic deletion of CB1receptors inThy1–YFP–Hmice elicited alterations in corticospinal tract development. Altogether, these data demonstrate that the CB1receptor contributes to the generation of deep-layer cortical neurons by coupling endocannabinoid signals from the neurogenic niche to the intrinsic proneurogenic Ctip2/Satb2 axis, thus influencing appropriate subcerebral projection neuron specification and corticospinal motor function in the adulthood.
Not All Errors Are Alike: Theta and Alpha EEG Dynamics Relate to Differences in Error-Processing Dynamics
Authors: van Driel Joram , Ridderinkhof K. Richard , Cohen Michael X
Published: November 2012

Performance errors in conflict tasks often result from inappropriate action impulses, and are thought to signal the need for increased control over the motor system. However, errors may also result from lapses in sustained attention, which may require different monitoring and adaptation mechanisms. Distinguishing between the mechanisms of adaptation is important as both error types may occur intermixed. To this end, we measured EEG of healthy human subjects while they performed three variants of the Simon task in which errors were more likely to occur due to attentional lapses, failures of motor control, or both. Behavioral results showed that subjects exhibited less conflict effects and less impulsive errors in sustained attention compared with the other Simon conditions. Time-frequency analyses of EEG data showed that the sustained attention Simon condition, compared with the motor control Simon condition, was characterized by: (1) less error-related MFC theta (4–8 Hz) power and an absence of error-related MFC–DLPFC theta phase synchronization; (2) stronger error-related suppression of parieto-occipital alpha (8–12 Hz) power and stronger parieto-occipital–frontal alpha synchronization. A control experiment, using SART (the Sustained Attention to Response Test), confirmed that adaptation after attentional lapses involved posterior alpha power suppression, in addition to inter-regional frontal theta activity. Together, these results suggest that at least two cortical mechanisms exist for performance monitoring, and that different tasks and task-settings can recruit these mechanisms in a different way. Post-error brain dynamics thus consist of heterogeneous activity from multiple neurocognitive processes.
RIM Promotes Calcium Channel Accumulation at Active Zones of theDrosophilaNeuromuscular Junction
Authors: Graf Ethan R. , Valakh Vera , Wright Christina M. , Wu Chunlai , Liu Zhihua , Zhang Yong Q. , DiAntonio Aaron
Published: November 2012

Synaptic communication requires the controlled release of synaptic vesicles from presynaptic axon terminals. Release efficacy is regulated by the many proteins that comprise the presynaptic release apparatus, including Ca2+channels and proteins that influence Ca2+channel accumulation at release sites. Here we identifyDrosophilaRIM (Rab3 interacting molecule) and demonstrate that it localizes to active zones at the larval neuromuscular junction. InDrosophilaRIM mutants, there is a large decrease in evoked synaptic transmission because of a significant reduction in both the clustering of Ca2+channels and the size of the readily releasable pool of synaptic vesicles at active zones. Hence, RIM plays an evolutionarily conserved role in regulating synaptic calcium channel localization and readily releasable pool size. Because RIM has traditionally been studied as an effector of Rab3 function, we investigate whether RIM is involved in the newly identified function of Rab3 in the distribution of presynaptic release machinery components across release sites. Bruchpilot (Brp), an essential component of the active zone cytomatrix T bar, is unaffected byRIMdisruption, indicating that Brp localization and distribution across active zones does not require wild-type RIM. In addition, larvae containing mutations in bothRIMandrab3have reduced Ca2+channel levels and a Brp distribution that is very similar to that of therab3single mutant, indicating that RIM functions to regulate Ca2+channel accumulation but is not a Rab3 effector for release machinery distribution across release sites.
Differential Distribution of Glycine Receptor Subtypes at the Rat Calyx of Held Synapse
Authors: Hruskova Bohdana , Trojanova Johana , Kulik Akos , Kralikova Michaela , Pysanenko Kateryna , Bures Zbynek , Syka Josef , Trussell Laurence O. , Turecek Rostislav
Published: November 2012

The properties of glycine receptors (GlyRs) depend upon their subunit composition. While the prevalent adult forms of GlyRs are heteromers, previous reports suggested functional α homomeric receptors in mature nervous tissues. Here we show two functionally different GlyRs populations in the rat medial nucleus of trapezoid body (MNTB). Postsynaptic receptors formed α1/β-containing clusters on somatodendritic domains of MNTB principal neurons, colocalizing with glycinergic nerve endings to mediate fast, phasic IPSCs. In contrast, presynaptic receptors on glutamatergic calyx of Held terminals were composed of dispersed, homomeric α1 receptors. Interestingly, the parent cell bodies of the calyces of Held, the globular bushy cells of the cochlear nucleus, expressed somatodendritic receptors (α1/β heteromers) and showed similar clustering and pharmacological profile as GlyRs on MNTB principal cells. These results suggest that specific targeting of GlyR β-subunit produces segregation of GlyR subtypes involved in two different mechanisms of modulation of synaptic strength.
Direct Alteration of a Specific Inhibitory Circuit of the Hippocampus by Antidepressants
Authors: Méndez Pablo , Pazienti Antonio , Szabó Gabor , Bacci Alberto
Published: November 2012

Correct brain functioning relies on the precise activity of a myriad of synapses assembling neurons in complex networks. In the hippocampus, highly diverse inhibitory circuits differently govern several physiologically relevant network activities. Particularly, perisomatic inhibition provided by specific interneurons was proposed to control emotional states, and could therefore be affected by mood disorders and their therapy. We found that both chronic and acute administration of two major antidepressants, imipramine and fluoxetine, strongly and directly altered GABA-mediated (GABAergic) hippocampal neurotransmission in mice and rats, independently of their effects on amine reuptake systems. These drugs affected GABA release from synapses formed by fast-spiking cells, but not interneurons expressing cannabinoid receptor type 1, resulting in the disruption of γ oscillations. This differential effect, shared by two types of antidepressants, suggests a new mechanism of action of these medications, and a possible role of perisomatic inhibition in depressive disorders.
Perceptual Criteria in the Human Brain
Authors: White Corey N. , Mumford Jeanette A. , Poldrack Russell A.
Published: November 2012

A critical component of decision making is the ability to adjust criteria for classifying stimuli. fMRI and drift diffusion models were used to explore the neural representations of perceptual criteria in decision making. The specific focus was on the relative engagement of perceptual- and decision-related neural systems in response to adjustments in perceptual criteria. Human participants classified visual stimuli as big or small based on criteria of different sizes, which effectively biased their choices toward one response over the other. A drift diffusion model was fit to the behavioral data to extract estimates of stimulus size, criterion size, and difficulty for each participant and condition. These parameter values were used as modulated regressors to create a highly constrained model for the fMRI analysis that accounted for several components of the decision process. The results show that perceptual criteria values were reflected by activity in left inferior temporal cortex, a region known to represent objects and their physical properties, whereas stimulus size was reflected by activation in occipital cortex. A frontoparietal network of regions, including dorsolateral prefrontal cortex and superior parietal lobule, corresponded to the decision variables resulting from the downstream stimulus–criterion comparison, independent of stimulus type. The results provide novel evidence that perceptual criteria are represented in stimulus space and serve as inputs to be compared with the presented stimulus, recruiting a common network of decision regions shown to be active in other simple decisions. This work advances our understanding of the neural correlates of decision flexibility and adjustments of behavioral bias.
An Effect of Bilingualism on the Auditory Cortex
Authors: Ressel Volker , Pallier Christophe , Ventura-Campos Noelia , Díaz Begoña , Roessler Abeba , Ávila César , Sebastián-Gallés Núria
Published: November 2012

Two studies (Golestani et al., 2007; Wong et al., 2008) have reported a positive correlation between the ability to perceive foreign speech sounds and the volume of Heschl's gyrus (HG), the structure that houses the auditory cortex. More precisely, participants with larger left Heschl's gyri learned consonantal or tonal contrasts faster than those with smaller HG. These studies leave open the question of the impact of experience on HG volumes. In the current research, we investigated the effect of early language exposure on Heschl's gyrus by comparing Spanish–Catalan bilinguals who have been exposed to two languages since childhood, to a group of Spanish monolinguals matched in education, socio-economic status, and musical experience. Manual volumetric measurements of HG revealed that bilinguals have, on average, larger Heschl's gyri than monolinguals. This was corroborated, for the left Heschl's gyrus, by a voxel-based morphometry analysis showing larger gray matter volumes in bilinguals than in monolinguals. Since the bilinguals in this study were not a self-selected group, this observation provides a clear demonstration that learning a second language is a causal factor in the increased size of the auditory cortex.
Sight and Sound Converge to Form Modality-Invariant Representations in Temporoparietal Cortex
Authors: Man Kingson , Kaplan Jonas T. , Damasio Antonio , Meyer Kaspar
Published: November 2012

People can identify objects in the environment with remarkable accuracy, regardless of the sensory modality they use to perceive them. This suggests that information from different sensory channels converges somewhere in the brain to form modality-invariant representations, i.e., representations that reflect an object independently of the modality through which it has been apprehended. In this functional magnetic resonance imaging study of human subjects, we first identified brain areas that responded to both visual and auditory stimuli and then used crossmodal multivariate pattern analysis to evaluate the neural representations in these regions for content specificity (i.e., do different objects evoke different representations?) and modality invariance (i.e., do the sight and the sound of the same object evoke a similar representation?). While several areas became activated in response to both auditory and visual stimulation, only the neural patterns recorded in a region around the posterior part of the superior temporal sulcus displayed both content specificity and modality invariance. This region thus appears to play an important role in our ability to recognize objects in our surroundings through multiple sensory channels and to process them at a supramodal (i.e., conceptual) level.
Precedence of the Eye Region in Neural Processing of Faces
Authors: Issa Elias B. , DiCarlo James J.
Published: November 2012

Functional magnetic resonance imaging (fMRI) has revealed multiple subregions in monkey inferior temporal cortex (IT) that are selective for images of faces over other objects. The earliest of these subregions, the posterior lateral face patch (PL), has not been studied previously at the neurophysiological level. Perhaps not surprisingly, we found that PL contains a high concentration of “face-selective” cells when tested with standard image sets comparable to those used previously to define the region at the level of fMRI. However, we here report that several different image sets and analytical approaches converge to show that nearly all face-selective PL cells are driven by the presence of a single eye in the context of a face outline. Most strikingly, images containing only an eye, even when incorrectly positioned in an outline, drove neurons nearly as well as full-face images, and face images lacking only this feature led to longer latency responses. Thus, bottom-up face processing is relatively local and linearly integrates features—consistent with parts-based models—grounding investigation of how the presence of a face is first inferred in the IT face processing hierarchy.
Hippocampal Phase Precession from Dual Input Components
Authors: Chance Frances S.
Published: November 2012

Phase precession is a well known phenomenon in which a hippocampal place cell will fire action potentials at successively earlier phases (relative to the theta-band oscillations recorded in the local field potential) as an animal moves through the cell's receptive field (also known as a place field). We present a model in which CA1 pyramidal cell spiking is driven by dual input components arising from CA3 and EC3. The receptive fields of these two input components overlap but are offset in space from each other such that as the animal moves through the model place field, action potentials are driven first by the CA3 input component and then the EC3 input component. As CA3 synaptic input is known to arrive in CA1 at a later theta phase than EC3 input (Mizuseki et al., 2009; Montgomery et al., 2009), CA1 spiking advances in phase as the model transitions from CA3-driven spiking to EC3-driven spiking. Here spike phase is a function of animal location, placing our results in agreement with many experimental observations characterizing CA1 phase precession (O'Keefe and Recce, 1993; Huxter et al., 2003; Geisler et al., 2007). We predict that experimental manipulations that dramatically enhance or disrupt activity in either of these areas should have a significant effect on phase precession observed in CA1.
Long-Term Neural Correlates of Reversible Fear Learning in the Lateral Amygdala
Authors: An Bobae , Hong Ingie , Choi Sukwoo
Published: November 2012

Fear conditioning and extinction are behavioral models that reflect the association and dissociation of environmental cues to aversive outcomes, both known to involve the lateral amygdala (LA). Accordingly, responses of LA neurons to conditioned stimuli (CS) increase after fear conditioning and decrease partially during extinction. However, the long-term effects of repeated fear conditioning and extinction on LA neuronal firing have not been explored. Here we show, using stable, high signal-to-noise ratio single-unit recordings, that the ensemble activity of all recorded LA neurons correlates tightly with conditioned fear responses of rats in a conditioning/extinction/reconditioning paradigm spanning 3 d. This CS-evoked ensemble activity increased after conditioning, decreased after extinction, and was repotentiated after reconditioning. Cell-by-cell analysis revealed that among the LA neurons that displayed potentiated responses after initial fear conditioning, some exhibited weakened CS responses after extinction (extinction-susceptible), whereas others remained potentiated (extinction-resistant). The majority of extinction-susceptible neurons exhibited strong potentiation after reconditioning, suggesting that this distinct subpopulation (reversible fear neurons) encodes updated CS–unconditioned stimulus (US) association strength. Interestingly, these reversible fear neurons displayed larger, more rapid potentiation during reconditioning compared with the initial conditioning, providing a neural correlate of savings after extinction. In contrast, the extinction-resistant fear neurons did not show further increases after reconditioning, suggesting that this subpopulation encodes persistent fear memory representing the original CS–US association. This longitudinal report on LA neuronal activity during reversible fear learning suggests the existence of distinct populations encoding various facets of fear memory and provides insight into the neuronal mechanisms of fear memory modulation.