bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual fixation in the vegetative state: an observational case series PET study
Authors: Bruno Marie-Aurélie , Vanhaudenhuyse Audrey , Schnakers Caroline , Boly Mélanie , Gosseries Olivia , Demertzi Athena , Majerus Steve , Moonen Gustave , Hustinx Roland , Laureys Steven
Published: May 2010

Background

Assessment of visual fixation is commonly used in the clinical examination of patients with disorders of consciousness. However, different international guidelines seem to disagree whether fixation is compatible with the diagnosis of the vegetative state (i.e., represents "automatic" subcortical processing) or is a sufficient sign of consciousness and higher order cortical processing.

Methods

We here studied cerebral metabolism in ten patients with chronic post-anoxic encephalopathy and 39 age-matched healthy controls. Five patients were in a vegetative state (without fixation) and five presented visual fixation but otherwise showed all criteria typical of the vegetative state. Patients were matched for age, etiology and time since insult and were followed by repeated Coma Recovery Scale-Revised (CRS-R) assessments for at least 1 year. Sustained visual fixation was considered as present when the eyes refixated a moving target for more than 2 seconds as defined by CRS-R criteria.

Results

Patients without fixation showed metabolic dysfunction in a widespread fronto-parietal cortical network (with only sparing of the brainstem and cerebellum) which was not different from the brain function seen in patients with visual fixation. Cortico-cortical functional connectivity with visual cortex showed no difference between both patient groups. Recovery rates did not differ between patients without or with fixation (none of the patients showed good outcome).

Conclusions

Our findings suggest that sustained visual fixation in (non-traumatic) disorders of consciousness does not necessarily reflect consciousness and higher order cortical brain function.
Expression signatures of TP53 mutations in serous ovarian cancers
Authors: Bernardini Marcus Q , Baba Tsukasa , Lee Paula S , Barnett Jason C , Sfakianos Gregory P , Secord Angeles Alvarez , Murphy Susan K , Iversen Edwin , Marks Jeffrey R , Berchuck Andrew
Published: May 2010

Background

Mutations in the TP53 gene are extremely common and occur very early in the progression of serous ovarian cancers. Gene expression patterns that relate to mutational status may provide insight into the etiology and biology of the disease.

Methods

The TP53 coding region was sequenced in 89 frozen serous ovarian cancers, 40 early stage (I/II) and 49 advanced stage (III/IV). Affymetrix U133A expression data was used to define gene expression patterns by mutation, type of mutation, and cancer stage.

Results

Missense or chain terminating (null) mutations in TP53 were found in 59/89 (66%) ovarian cancers. Early stage cancers had a significantly higher rate of null mutations than late stage disease (38% vs. 8%, p < 0.03). In advanced stage cases, mutations were more prevalent in short term survivors than long term survivors (81% vs. 30%, p = 0.0004). Gene expression patterns had a robust ability to predict TP53 status within training data. By using early versus late stage disease for out of sample predictions, the signature derived from early stage cancers could accurately (86%) predict mutation status of late stage cancers.

Conclusions

This represents the first attempt to define a genomic signature of TP53 mutation in ovarian cancer. Patterns of gene expression characteristic of TP53 mutation could be discerned and included several genes that are known p53 targets or have been described in the context of expression signatures of TP53 mutation in breast cancer.
Assessing agonistic potential of a candidate therapeutic anti-IL21R antibody
Authors: Guo Yongjing , Hill Andrew A , Ramsey Renee C , Immermann Frederick W , Corcoran Christopher , Young Deborah , LaVallie Edward R , Ryan Mark , Bechard Theresa , Pfeifer Richard , Warner Garvin , Bologna Marcia , Bloom Laird , O'Toole Margot
Published: May 2010

Background

Selective neutralization of the IL21/IL21R signaling pathway is a promising approach for the treatment of a variety of autoimmune diseases. Ab-01 is a human neutralizing anti-IL21R antibody. In order to ensure that the activities of Ab-01 are restricted to neutralization even under in vitro cross-linking and in vivo conditions, a comprehensive assessment of agonistic potential of Ab-01 was undertaken.

Methods

In vitro antibody cross-linking and cell culture protocols reported for studies with a human agonistic antibody, TGN1412, were followed for Ab-01. rhIL21, the agonist ligand of the targeted receptor, and cross-linked anti-CD28 were used as positive controls for signal transduction. In vivo agonistic potential of Ab-01 was assessed by measuring expression levels of cytokine storm-associated and IL21 pathway genes in blood of cynomolgus monkeys before and after IV administration of Ab-01.

Results

Using a comprehensive set of assays that detected multiple activation signals in the presence of the positive control agonists, in vitro Ab-01-dependent activation was not detected in either PBMCs or the rhIL21-responsive cell line Daudi. Furthermore, no difference in gene expression levels was detected in blood before and after in vivo Ab-01 dosing of cynomolgus monkeys.

Conclusions

Despite efforts to intentionally force an agonistic signal from Ab-01, none could be detected.
Relationship between Asthma and Rhinitis: Epidemiologic, Pathophysiologic, and Therapeutic Aspects
Authors: Bergeron Celine , Hamid Qutayba
Published: May 2010

Over the last few years, the evidence of links between rhinitis and asthma has been strengthened. This has led to the introduction of the concept of united airway disease. Rhinitis and asthma appear to be interrelated at the epidemiologic level and at the pathophysiologic level. This article reviews current epidemiologic and pathophysiologic evidence of the relationship between rhinitis and asthma and discusses the effect of treatment of one site on the other site.
Spartin activates atrophin-1-interacting protein 4 (AIP4) E3 ubiquitin ligase and promotes ubiquitination of adipophilin on lipid droplets
Authors: Hooper Christopher , Puttamadappa Swamy S , Loring Zak , Shekhtman Alexander , Bakowska Joanna C
Published: May 2010

Background

Spartin protein is involved in degradation of epidermal growth factor receptor and turnover of lipid droplets and a lack of expression of this protein is responsible for hereditary spastic paraplegia type 20 (SPG20). Spartin is a multifunctional protein that associates with many cellular organelles, including lipid droplets. Recent studies showed that spartin interacts with E3 ubiquitin ligases that belong to the neural precursor cell-expressed developmentally downregulated gene (Nedd4) family, including atrophin-1-interacting protein 4 (AIP4/ITCH). However, the biological importance of the spartin-AIP4 interaction remains unknown.

Results

In this study, we show that spartin is not a substrate for AIP4 activity and that spartin's binding to AIP4 significantly increases self-ubiquitination of this E3 ligase, indicating that spartin disrupts the AIP4 autoinhibitory intramolecular interaction. Correspondingly, spartin has a seven times higher binding affinity to the WW region of AIP4 than the binding of the WW region has to the catalytic homologues of the E6-associated protein C-terminus (HECT) domain, as measured by enzyme-linked immunosorbent assay. We also show that spartin recruits AIP4 to lipid droplets and promotes ubiquitination of lipid droplet-associated protein, adipophilin, which regulates turnover of lipid droplets.

Conclusions

Our findings demonstrate that spartin acts as an adaptor protein that activates and recruits AIP4 E3 ubiquitin ligase to lipid droplets and by this means regulates the level of ubiquitination of adipophilin and potentially other lipid-associated proteins. We propose that this is one of the mechanisms by which spartin regulates lipid droplet turnover and might contribute to the pathology of SPG20.
In vivo Patch-Clamp Analysis of Response Properties of Rat Primary Somatosensory Cortical Neurons Responding to Noxious Stimulation of the Facial Skin
Authors: Takeda Mamoru , Takahashi Masayuki , Nasu Masanori , Matsumoto Shigeji
Published: May 2010

Background:

Although it has been widely accepted that the primary somatosensory (SI) cortex plays an important role in pain perception, it still remains unclear how the nociceptive mechanisms of synaptic transmission occur at the single neuron level. The aim of the present study was to examine whether noxious stimulation applied to the orofacial area evokes the synaptic response of SI neurons in urethane-anesthetized rats using an in vivo patch-clamp technique.

Results:

In vivo whole-cell current-clamp recordings were performed in rat SI neurons (layers III-IV). Twenty-seven out of 63 neurons were identified in the mechanical receptive field of the orofacial area (36 neurons showed no receptive field) and they were classified as non-nociceptive (low-threshold mechanoreceptive; 6/27, 22%) and nociceptive neurons. Nociceptive neurons were further divided into wide-dynamic range neurons (3/27, 11 %) and nociceptive-specific neurons (18/27, 67%). In the majority of these neurons, a proportion of the excitatory postsynaptic potentials (EPSPs) reached the threshold, and then generated random discharges of action potentials. Noxious mechanical stimuli applied to the receptive field elicited a discharge of action potentials on the barrage of EPSPs. In the case of noxious chemical stimulation applied as mustard oil to the orofacial area, the membrane potential shifted depolarization and the rate of spontaneous discharges gradually increased as did the noxious pinch-evoked discharge rates, which were usually associated with potentiated EPSP amplitudes.

Conclusions:

The present study provides evidence that SI neurons in deep layers III–V respond to the temporal summation of EPSPs due to noxious mechanical and chemical stimulation applied to the orofacial area and that these neurons may contribute to the processing of nociceptive information, including hyperalgesia.
The BRACELET Study: surveys of mortality in UK neonatal and paediatric intensive care trials
Authors: Snowdon Claire , Harvey Sheila E , Brocklehurst Peter , Tasker Robert C , Platt Martin P Ward , Allen Elizabeth , Elbourne Diana
Published: May 2010

Background

The subject of death and bereavement in the context of randomised controlled trials in neonatal or paediatric intensive care is under-researched. The objectives of this phase of the Bereavement and RAndomised ControlLEd Trials (BRACELET) Study were to determine trial activity in UK neonatal and paediatric intensive care (2002-06); numbers of deaths before hospital discharge; and variation in mortality across intensive care units and trials and to determine whether bereavement support policies were available within trials. These are essential prerequisites to considering the implications of future policies and practice subsequent to bereavement following a child's enrolment in a trial.

Methods

The units survey involved neonatal units providing level 2 or 3 care, and paediatric units providing level II care or above; the trials survey involved trials where allocation was randomized and interventions were delivered to intensive care patients, or to parents but designed to affect patient outcomes.

Results

Information was available from 191/220 (87%) neonatal units (149 level 2 or 3 care); and 28/32 (88%) paediatric units. 90/177 (51%) eligible responding units participated in one or more trial (76 neonatal, 14 paediatric) and 54 neonatal units and 6 paediatric units witnessed at least one death. 50 trials were identified (36 neonatal, 14 paediatric). 3,137 babies were enrolled in neonatal trials, 210 children in paediatric trials. Deaths ranged 0-278 (median [IQR interquartile range] 2 [1, 14.5]) per neonatal trial, 0-4 (median [IQR] 1 [0, 2.5]) per paediatric trial. 534 (16%) participants died post-enrolment: 522 (17%) in neonatal trials, 12 (6%) in paediatric trials. Trial participants ranged 1-236 (median [IQR] 21.5 [8, 39.8]) per neonatal unit, 1-53 (median [IQR] 11.5 [2.3, 33.8]) per paediatric unit. Deaths ranged 0-37 (median [IQR] 3.5 [0.3, 8.8]) per neonatal unit, 0-7 (median [IQR] 0.5 [0, 1.8]) per paediatric unit. Three trials had a formal policy for responding to bereavement.

Conclusions

A substantial number of deaths after trial enrolment were identified, distributed over many trials and units. Few trial teams had responses to bereavement in place. Those with the largest numbers of deaths might be best placed to collaborate in developing and assessing responses to bereavement.
The diversity and evolution of cell cycle regulation in alpha-proteobacteria: a comparative genomic analysis
Authors: Brilli Matteo , Fondi Marco , Fani Renato , Mengoni Alessio , Ferri Lorenzo , Bazzicalupo Marco , Biondi Emanuele G
Published: May 2010

Background

In the bacterium Caulobacter crescentus, CtrA coordinates DNA replication, cell division, and polar morphogenesis and is considered the cell cycle master regulator. CtrA activity varies during cell cycle progression and is modulated by phosphorylation, proteolysis and transcriptional control. In a phosphorylated state, CtrA binds specific DNA sequences, regulates the expression of genes involved in cell cycle progression and silences the origin of replication. Although the circuitry regulating CtrA is known in molecular detail in Caulobacter, its conservation and functionality in the other alpha-proteobacteria are still poorly understood.

Results

Orthologs of Caulobacter factors involved in the regulation of CtrA were systematically scanned in genomes of alpha-proteobacteria. In particular, orthologous genes of the divL-cckA-chpT-ctrA phosphorelay, the divJ-pleC-divK two-component system, the cpdR-rcdA-clpPX proteolysis system, the methyltransferase ccrM and transcriptional regulators dnaA and gcrA were identified in representative genomes of alpha-proteobacteria. CtrA, DnaA and GcrA binding sites and CcrM putative methylation sites were predicted in promoter regions of all these factors and functions controlled by CtrA in all alphas were predicted.

Conclusions

The regulatory cell cycle architecture was identified in all representative alpha-proteobacteria, revealing a high diversification of circuits but also a conservation of logical features. An evolutionary model was proposed where ancient alphas already possessed all modules found in Caulobacter arranged in a variety of connections. Two schemes appeared to evolve: a complex circuit in Caulobacterales and Rhizobiales and a simpler one found in Rhodobacterales.
Amplified fragment length polymorphism (AFLP) analysis of closely related wild and captive tsetse fly (Glossina morsitans morsitans) populations
Authors: Lall Gurdeep K , Darby Alistair C , Nystedt Bjorn , MacLeod Ewan T , Bishop Richard P , Welburn Susan C
Published: May 2010

Background

Tsetse flies (Diptera: Glossinidae) are vectors of trypanosomes that cause sleeping sickness in humans and nagana in livestock across sub-Saharan Africa. Tsetse control strategies rely on a detailed understanding of the epidemiology and ecology of tsetse together with genetic variation within and among populations. High-resolution nuclear genetic markers are useful tools for elucidation of the genetic basis of phenotypic traits. In this study amplified fragment length polymorphism (AFLP) markers were developed to analyze genetic variation in Glossina morsitans morsitans from laboratory and field-collected populations from Zimbabwe.

Results

A total of seven hundred and fifty one loci from laboratory and field populations of G. m. morsitans from Zimbabwe were genotyped using AFLP with seven primer combinations. Analysis identified 335 polymorphic loci. The two populations could be distinguished by cluster and principal components analysis (PCA) analysis, indicating that AFLP markers can be used to separate genetically similar populations; at the same time differences observed between laboratory and field populations were not very great. Among the techniques investigated, the use of acetone was the most reliable method of preservation of tsetse for subsequent extraction of high molecular weight DNA. An interesting finding was that AFLP also enabled robust within-population discrimination of male and female tsetse flies due to their different X chromosome DNA complements.

Conclusions

AFLP represents a useful additional tool to add to the suite of techniques currently available for the genetic analysis of tsetse populations and represents a useful resource for identification of the genetic basis of important phenotypic traits.
Early alterations of the innate and adaptive immune statuses in sepsis according to the type of underlying infection
Authors: Gogos Charalambos , Kotsaki Antigone , Pelekanou Aimilia , Giannikopoulos George , Vaki Ilia , Maravitsa Panagiota , Adamis Stephanos , Alexiou Zoi , Andrianopoulos George , Antonopoulou Anastasia , Athanassia Sofia , Baziaka Fotini , Charalambous Aikaterini , Christodoulou Sofia , Dimopoulou Ioanna , Floros Ioannis , Giannitsioti Efthymia , Gkanas Panagiotis , Ioakeimidou Aikaterini , Kanellakopoulou Kyriaki , Karabela Niki , Karagianni Vassiliki , Katsarolis Ioannis , Kontopithari Georgia , Kopterides Petros , Koutelidakis Ioannis , Koutoukas Pantelis , Kranidioti Hariklia , Lignos Michalis , Louis Konstantinos , Lymberopoulou Korina , Mainas Efstratios , Marioli Androniki , Massouras Charalambos , Mavrou Irini , Mpalla Margarita , Michalia Martha , Mylona Heleni , Mytas Vassilios , Papanikolaou Ilias , Papanikolaou Konstantinos , Patrani Maria , Perdios Ioannis , Plachouras Diamantis , Pistiki Aikaterini , Protopapas Konstantinos , Rigaki Kalliopi , Sakka Vissaria , Sartzi Monika , Skouras Vassilios , Souli Maria , Spyridaki Aikaterini , Strouvalis Ioannis , Tsaganos Thomas , Zografos George , Mandragos Konstantinos , Klouva-Molyvdas Phylis , Maggina Nina , Giamarellou Helen , Armaganidis Apostolos , Giamarellos-Bourboulis Evangelos J
Published: May 2010

Introduction

Although major changes of the immune system have been described in sepsis, it has never been studied whether these may differ in relation to the type of underlying infection or not. This was studied for the first time.

Methods

The statuses of the innate and adaptive immune systems were prospectively compared in 505 patients. Whole blood was sampled within less than 24 hours of advent of sepsis; white blood cells were stained with monoclonal antibodies and analyzed though a flow cytometer.

Results

Expression of HLA-DR was significantly decreased among patients with severe sepsis/shock due to acute pyelonephritis and intraabdominal infections compared with sepsis. The rate of apoptosis of natural killer (NK) cells differed significantly among patients with severe sepsis/shock due to ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) compared with sepsis. The rate of apoptosis of NKT cells differed significantly among patients with severe sepsis/shock due to acute pyelonephritis, primary bacteremia and VAP/HAP compared with sepsis. Regarding adaptive immunity, absolute counts of CD4-lymphocytes were significantly decreased among patients with severe sepsis/shock due to community-acquired pneumonia (CAP) and intraabdominal infections compared with sepsis. Absolute counts of B-lymphocytes were significantly decreased among patients with severe sepsis/shock due to CAP compared with sepsis.

Conclusions

Major differences of the early statuses of the innate and adaptive immune systems exist between sepsis and severe sepsis/shock in relation to the underlying type of infection. These results may have a major impact on therapeutics.
Delineating Biological Pathways Unique to Embryonic Stem Cell-Derived Insulin-Producing Cell Lines from Their Noninsulin-Producing Progenitor Cell Lines
Authors: Chen Tian Sheng , Tan Soon Sim , Yeo Ronne Wee Yeh , Teh Bao Ju , Luo Ruihua , Li GuoDong , Lim Sai Kiang
Published: May 2010

To identify unique biochemical pathways in embryonic stem cell-derived insulin-producing cells as potential therapeutic targets to prevent or delay β-cell dysfunction or death in diabetic patients, comparative genome-wide gene expression studies of recently derived mouse insulin-producing cell lines and their progenitor cell lines were performed using microarray technology. Differentially expressed genes were functionally clustered to identify important biochemical pathways in these insulin-producing cell lines. Biochemical or cellular assays were then performed to assess the relevance of these pathways to the biology of these cells. A total of 185 genes were highly expressed in the insulin-producing cell lines, and computational analysis predicted the pentose phosphate pathway (PPP), clathrin-mediated endocytosis, and the peroxisome proliferator-activated receptor (PPAR) signaling pathway as important pathways in these cell lines. Insulin-producing ERoSHK cells were more resistant to hydrogen peroxide (H2O2)-induced oxidative stress. Inhibition of PPP by dehydroepiandrosterone and 6-aminonicotinamide abrogated this H2O2 resistance with a concomitant decrease in PPP activity as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Clathrin-mediated endocytosis, which is essential in maintaining membrane homeostasis in secreting cells, was up-regulated by glucose in ERoSHK but not in their progenitor ERoSH cells. Its inhibition by chlorpromazine at high glucose concentration was toxic to the cells. Troglitazone, a PPARG agonist, up-regulated expression of Ins1 and Ins2 but not Glut2. Gene expression analysis has identified the PPP, clathrin-mediated endocytosis, and the PPAR signaling pathway as the major delineating pathways in these insulin-producing cell lines, and their biological relevance was confirmed by biochemical and cellular assays.
Mammary Ductal Growth Is Impaired in Mice Lacking Leptin-Dependent Signal Transducer and Activator of Transcription 3 Signaling
Authors: Thorn Stephanie R. , Giesy Sarah L. , Myers Martin G. , Boisclair Yves R.
Published: May 2010

Mice lacking leptin (ob/ob) or its full-length receptor (db/db) are obese and reproductively incompetent. Fertility, pregnancy, and lactation are restored, respectively, in ob/ob mice treated with leptin through mating, d 6.5 post coitum, and pregnancy. Therefore, leptin signaling is needed for lactation, but the timing of its action and the affected mammary process remain unknown. To address this issue, we used s/s mice lacking only leptin-dependent signal transducer and activator of transcription (STAT)3 signaling. These mice share many features with db/db mice, including obesity, but differ by retaining sufficient activity of the hypothalamic-pituitary-ovarian axis to support reproduction. The s/s mammary epithelium was normal at 3 wk of age but failed to expand through the mammary fat pad (MFP) during the subsequent pubertal period. Ductal growth failure was not corrected by estrogen therapy and did not relate to inadequate IGF-I production by the MFP or to the need for epithelial or stromal leptin-STAT3 signaling. Ductal growth failure coincided with adipocyte hypertrophy and increased MFP production of leptin, TNFα, and IL6. These cytokines, however, were unable to inhibit the proliferation of a collection of mouse mammary epithelial cell lines. In conclusion, the very first step of postnatal mammary development fails in s/s mice despite sufficient estrogen IGF-I and an hypothalamic-pituitary-ovarian axis capable of supporting reproduction. This failure is not caused by mammary loss of leptin-dependent STAT3 signaling or by the development of inflammation. These data imply the existence of an unknown mechanism whereby leptin-dependent STAT3 signaling and obesity alter mammary ductal development.
Diabetes Prevention by Immunomodulatory FTY720 Treatment in the LEW.1AR1-iddm Rat Despite Immune Cell Activation
Authors: Jörns Anne , Rath Klaus Jan , Terbish Taivankhuu , Arndt Tanja , Meyer zu Vilsendorf Andreas , Wedekind Dirk , Hedrich Hans-Jürgen , Lenzen Sigurd
Published: May 2010

The prevention of diabetes by the immunomodulatory agent FTY720 (fingolimod) was studied in the LEW.1AR1-iddm (IDDM) rat, an animal model of human type 1 diabetes. Immune cell subtypes and cytokine profiles in pancreatic islets, secondary lymphoid tissue, and serum were analyzed for signs of immune cell activation. Animals were treated with FTY720 (1 mg/kg body weight) for 40 d starting on d 50 of life. Changes in gene and protein expression of cytokines, CD8 markers, monocyte chemoattractant protein-1, inducible NO synthase, and caspase 3 were evaluated. Treatment with FTY720 prevented diabetes manifestation and islet infiltration around d 60 of life, the usual time of spontaneous diabetes development. On d 120, 30 d after the end of FTY720 therapy, diabetes prevention persisted. However, six of 12 treated animals showed increased gene expression of IL-1β, TNF-α, and CD8 markers in pancreas-draining lymph nodes, indicating immune cell activation. In parallel, serum concentrations of these proinflammatory cytokines were increased. These six animals also showed macrophage infiltration without proinflammatory cytokine expression in a small minority (2–3%) of islets. Interestingly, regulatory T lymphocytes were significantly increased in the efferent vessels of the pancreas-draining lymph nodes only in animals without signs of immune cell activation but not in the rats with immune cell activation. This provides an indication for a lack of protective capacity in the animals with activated immune cells. Thus, FTY720 treatment prevented the manifestation of diabetes by promoting the retention of activated immune cells in the lymph nodes, thereby avoiding islet infiltration and β-cell destruction by proinflammatory cytokines.
Contribution of TNF-α and Nuclear Factor-κB Signaling to Type 2 Iodothyronine Deiodinase Activation in the Mediobasal Hypothalamus after Lipopolysaccharide Administration
Authors: Sánchez Edith , Singru Praful S. , Wittmann Gábor , Nouriel Shira S. , Barrett Perry , Fekete Csaba , Lechan Ronald M.
Published: May 2010

To determine whether signaling through TNF and/or nuclear factor-κB contributes to bacterial lipopolysaccharide (LPS)-induced activation of type 2 iodothyronine deiodinase (D2) in tanycytes lining the floor and infralateral walls of the third ventricle, the effect of a TNF antagonist on D2 gene expression and LPS-induced Iκ-Bα expression in tanycytes were studied. Animals treated with soluble, rat, polyethylene glycol-conjugated TNF receptor type 1 (4 mg/kg body weight) before a single ip injection of LPS showed a significant reduction in circulating IL-6 levels but no effect on LPS-induced D2 mRNA in the majority of tanycytes with the exception of a subpopulation of α tanycytes in the wall of the third ventricle. LPS induced a rapid increase in Iκ-Bα mRNA in the pars tuberalis and a delayed response in α tanycytes but absent in all other tanycyte subsets. The LPS-induced increase in Iκ-Bα in the pars tuberalis was associated with increased TSHβ gene expression in this tissue, but cAMP response element-binding protein (CREB) phosphorylation was observed only in a subset of α tanycytes. These data suggest that TNF and nuclear factor-κB signaling are not the primary, initiating mechanisms mediating the LPS-induced D2 response in tanycytes, but may contribute in part to sustaining the LPS-induced D2 response in a subset of α tanycytes. We hypothesize that in addition to TSH, other factors derived from the pars tuberalis may contribute to LPS-induced D2 activation in tanycytes.
Regulation of BMP-dependent chondrogenesis in early limb mesenchyme by TGFβ signals
Authors: Karamboulas Konstantina , Dranse Helen J. , Underhill T. Michael
Published: May 2010

In the developing axial skeleton, sequential sonic hedgehog (SHH) and bone morphogenetic protein (BMP) signals are required for specification of a chondrogenic fate in presomitic tissue. A similar paradigm is thought to operate in the limb, but the signals involved are unclear. To investigate the nature of these signals, we examined BMP action in mesenchymal populations derived from the early murine limb bud (approximately embryonic day 10.5). These populations exhibited a graded response to BMPs, in which early limb mesenchymal cells (from the distal hind limb) displayed an anti-chondrogenic response, whereas BMPs promoted chondrogenesis in more mature cell populations (from the proximal fore limb). Under these conditions, multiple Gata genes were induced by BMPs and the extent of induction correlated with BMP anti-chondrogenic activity. A screen of limb-bud-expressed ligands revealed that prior short-term exposure to transforming growth factor β1 (TGFβ1) ameliorated the anti-chondrogenic response to BMP. Furthermore, brief activation of the TGFβ pathway was found to be necessary for subsequent induction of chondrogenesis by BMPs. Our findings indicate that, similar to axial skeletogenesis, induction of chondrogenesis in the appendicular skeleton is a two-step process. However, the programs differ in the transient signals driving chondrogenic responsiveness to BMPs, with SHH operating in the former and TGFβ activation in the latter.
Two-step colocalization of MORC3 with PML nuclear bodies
Authors: Mimura Yasuhiro , Takahashi Keiko , Kawata Kiyo , Akazawa Takashi , Inoue Norimitsu
Published: May 2010

Many functional subdomains, including promyelocytic leukemia nuclear bodies (PML NBs), are formed in the mammalian nucleus. Various proteins are constitutively or transiently accumulated in PML NBs in a PML-dependent manner. MORC3 (microrchidia family CW-type zinc-finger 3), also known as NXP2, which consists of GHL-ATPase, a CW-type zinc-finger and coiled-coil domains, is localized in PML NBs, where it recruits and activates p53 to induce cellular senescence. Interestingly, we found that MORC3 can form PML-independent nuclear domains (NDs) in mouse hematopoietic cells and even in Pml-deficient cells. Here, we show that MORC3 colocalizes with PML by a two-step molecular mechanism: the PML-independent formation of MORC3 NDs by the ATPase cycle, and the association of MORC3 with PML via the SUMO1-SUMO-interacting motif (SIM). Similarly to other members of the GHL-ATPase family, MORC3 functions as a ‘molecular clamp’. ATP binding induces conformational changes in MORC3, leading to the formation of MORC3 NDs, and subsequent ATP hydrolysis mediates the diffusion and binding of MORC3 to the nuclear matrix. MORC3 might clamp DNA or nucleosomes in MORC3 NDs via the CW domain. Furthermore, the SUMOylation of MORC3 at five sites was involved in the association of MORC3 with PML, and SUMO1-unmodified MORC3 formed NDs independently of PML.
Trafficking activity of myosin XXI is required in assembly ofLeishmaniaflagellum
Authors: Katta Santharam S. , Tammana Trinadh V. Satish , Sahasrabuddhe Amogh A. , Bajpai Virendra K. , Gupta Chhitar M.
Published: May 2010

Actin-based myosin motors have a pivotal role in intracellular trafficking in eukaryotic cells. The parasitic protozoan organism Leishmania expresses a novel class of myosin, myosin XXI (Myo21), which is preferentially localized at the proximal region of the flagellum. However, its function in this organism remains largely unknown. Here, we show that Myo21 interacts with actin, and its expression is dependent of the growth stage. We further reveal that depletion of Myo21 levels results in impairment of the flagellar assembly and intracellular trafficking. These defects are, however, reversed by episomal complementation. Additionally, it is shown that deletion of the Myo21 gene leads to generation of ploidy, suggesting an essential role of Myo21 in survival of Leishmania cells. Together, these results indicate that actin-dependent trafficking activity of Myo21 is essentially required during assembly of the Leishmania flagellum.
The spatial foundations of the conceptual system
Authors: Mandler Jean M.
Published: May 2010

This article proposes that the representation of concepts in infancy is in the form of spatial image-schemas. A mechanism that simplifies spatial information is described along with a small set of spatial primitives that are sufficient to account for the conceptualizations that preverbal infants use to interpret objects and events. This early system is important to understand because it organizes the adult conceptual system of objects and events and remains its core. With development, the system becomes enriched by language in several ways, and also by means of analogical extension to non-spatial information. Nonspatial bodily information, such as feelings of force and motor activity, is also added, but remains secondary. It becomes associated with spatial representations, but except for its spatial aspects is represented in a more inchoate and less accessible fashion.
Pacemaking in Dopaminergic Ventral Tegmental Area Neurons: Depolarizing Drive from Background and Voltage-Dependent Sodium Conductances
Authors: Khaliq Zayd M. , Bean Bruce P.
Published: May 2010

Dopaminergic neurons in the ventral tegmental area (VTA) fire spontaneously in a pacemaker-like manner. We analyzed the ionic currents that drive pacemaking in dopaminergic VTA neurons, studied in mouse brain slices. Pacemaking was not inhibited by blocking hyperpolarization-activated cation current (Ih) or blocking all calcium current by Mg2+replacement of Ca2+. Tetrodotoxin (TTX) stopped spontaneous activity and usually resulted in stable resting potentials near −60 mV to −55 mV, 10–15 mV below the action potential threshold. When external sodium was replaced byN-methyl-d-glucamine (NMDG) with TTX present, cells hyperpolarized by an average of −11 mV, suggesting a significant resting sodium conductance not sensitive to TTX. Voltage-clamp experiments using slow (10 mV/s) ramps showed a steady-state, steeply voltage-dependent current blocked by TTX that activates near −60 mV, as well as a sodium “background” current with little voltage sensitivity, revealed by NMDG replacement for sodium with TTX present. We quantified these two components of sodium current during the pacemaking trajectory using action potential clamp. The initial phase of depolarization, up to approximately −55 mV, is driven mainly by non-voltage-dependent sodium background current. Above −55 mV, TTX-sensitive voltage-dependent “persistent” Na current helps drive the final phase of depolarization to the spike threshold. Voltage-dependent calcium current is small at all subthreshold voltages. The pacemaking mechanism in VTA neurons differs from that in substantia nigra pars compacta (SNc) neurons, where subthreshold calcium current plays a dominant role. In addition, we found that non-voltage-dependent background sodium current is much smaller in SNc neurons than VTA neurons.
Perceptual Decisions Formed by Accumulation of Audiovisual Evidence in Prefrontal Cortex
Authors: Noppeney Uta , Ostwald Dirk , Werner Sebastian
Published: May 2010

To form perceptual decisions in our multisensory environment, the brain needs to integrate sensory information derived from a common source and segregate information emanating from different sources. Combining fMRI and psychophysics in humans, we investigated how the brain accumulates sensory evidence about a visual source in the context of congruent or conflicting auditory information. In a visual selective attention paradigm, subjects (12 females, 7 males) categorized video clips while ignoring concurrent congruent or incongruent soundtracks. Visual and auditory information were reliable or unreliable. Our behavioral data accorded with accumulator models of perceptual decision making, where sensory information is integrated over time until a criterion amount of information is obtained. Behaviorally, subjects exhibited audiovisual incongruency effects that increased with the variance of the visual and the reliability of the interfering auditory input. At the neural level, only the left inferior frontal sulcus (IFS) showed an “audiovisual-accumulator” profile consistent with the observed reaction time pattern. By contrast, responses in the right fusiform were amplified by incongruent auditory input regardless of sensory reliability. Dynamic causal modeling showed that these incongruency effects were mediated via connections from auditory cortex. Further, while the fusiform interacted with IFS in an excitatory recurrent loop that was strengthened for unreliable task-relevant visual input, the IFS did not amplify and even inhibited superior temporal activations for unreliable auditory input. To form decisions that guide behavioral responses, the IFS may accumulate audiovisual evidence by dynamically weighting its connectivity to auditory and visual regions according to sensory reliability and decisional relevance.
Amygdala-Specific Reduction of α1-GABAAReceptors Disrupts the Anticonvulsant, Locomotor, and Sedative, But Not Anxiolytic, Effects of Benzodiazepines in Mice
Authors: Heldt Scott A. , Ressler Kerry J.
Published: May 2010

The heterogeneity and distribution of GABAAreceptor subunits mediates differential roles in behavior. It is thought that particular behavioral responses to benzodiazepine (BZ) ligands might be associated with an action at a regionally defined receptor subtype. However, the role of specific GABAAreceptor subtypes in particular brain regions is less clear. Such detailed knowledge of regional α1-GABAAreceptor function will advance our understanding of the neural circuitry underlying the role of GABAAreceptors and the effects of GABAA-modulating drugs on behavior. By combining inducible, site-specific α1 subunit deletion, using a lentivirus expressing Cre-recombinase in mice with the α1 subunit gene flanked by loxP sites, we examine baseline and pharmacological effects of deletion of amygdala α1-GABAAreceptors. We find that amygdala-specific reduction of α1 receptor subunits does not affect mRNA or protein levels of amygdala α2 or α3 subunit receptors. Nor does this inducible reduction affect baseline locomotion or measures of anxiety. However, we also find that this inducible, site-specific deletion does disrupt the normal sedative-locomotor inhibition as well as the anticonvulsive effects, of two distinct BZ-site ligands, diazepam and zolpidem, which is relatively α1-subunit selective. These data, using inducible, region and subunit-specific deletion, combined with pharmacogenetic approaches, demonstrate that amygdala expression of the α1-GABAAreceptor subunit is required for normal BZ effects on sedation, locomotion, and seizure inhibition, but not for anxiolysis.
Parvalbumin Deficiency and GABAergic Dysfunction in Mice Lacking PGC-1α
Authors: Lucas Elizabeth K. , Markwardt Sean J. , Gupta Swati , Meador-Woodruff James H. , Lin Jiandie D. , Overstreet-Wadiche Linda , Cowell Rita M.
Published: May 2010

The transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) is a master regulator of metabolism in peripheral tissues, and it has been proposed that PGC-1α plays a similar role in the brain. Recent evidence suggests that PGC-1α is concentrated in GABAergic interneurons, so we investigated whether male and female PGC-1α −/− mice exhibit abnormalities in interneuron gene expression and/or function. We found a striking reduction in the expression of the Ca2+-binding protein parvalbumin (PV), but not other GABAergic markers, throughout the cerebrum in PGC-1α +/− and −/− mice. Furthermore, PGC-1α overexpression in cell culture was sufficient to robustly induce PV expression. Consistent with a reduction in PV rather than a loss of PV-expressing interneurons, spontaneous synaptic inhibition was not altered in PGC-1α −/− mice. However, evoked synaptic responses displayed less paired-pulse depression and dramatic facilitation in response to repetitive stimulation at the gamma frequency. PV transcript expression was also significantly reduced in retina and heart of PGC-1α −/− animals, suggesting that PGC-1α is required for proper expression of PV in multiple tissues. Together these findings indicate that PGC-1α is a novel regulator of interneuron gene expression and function and a potential therapeutic target for neurological disorders associated with interneuron dysfunction.
The Calmodulin-Stimulated Adenylate Cyclase ADCY8 Sets the Sensitivity of Zebrafish Retinal Axons to Midline Repellents and Is Required for Normal Midline Crossing
Authors: Xu Hong , Leinwand Sarah G. , Dell Alison L. , Fried-Cassorla Emma , Raper Jonathan A.
Published: May 2010

The chemokine SDF1 activates a cAMP-mediated signaling pathway that antagonizes retinal responses to the midline repellent slit. We show that knocking down the calmodulin-activated adenylate cyclase ADCY8 makes retinal axons insensitive to SDF1. Experimentsin vivousing male and female zebrafish (Danio rerio) confirm a mutual antagonism between slit signaling and ADCY8-mediated signaling. Unexpectedly, knockdown of ADCY8 or another calmodulin-activated cyclase, ADCY1, induces ipsilateral misprojections of retinal axons that would normally cross the ventral midline. We demonstrate a cell-autonomous requirement for ADCY8 in retinal neurons for normal midline crossing. These findings are the first to show that ADCY8 is required for axonal pathfinding before axons reach their targets. They support a model in which ADCY8 is an essential component of a signaling pathway that opposes repellent signaling. Finally, they demonstrate that ADCY8 helps regulate retinal sensitivity to midline guidance cues.
Dopaminergic Modulation of Endocannabinoid-Mediated Plasticity at GABAergic Synapses in the Prefrontal Cortex
Authors: Chiu Chiayu Q. , Puente Nagore , Grandes Pedro , Castillo Pablo E.
Published: May 2010

Similar to dopamine (DA), cannabinoids strongly influence prefrontal cortical functions, such as working memory, emotional learning, and sensory perception. Although endogenous cannabinoid receptors (CB1Rs) are abundantly expressed in the prefrontal cortex (PFC), very little is known about endocannabinoid (eCB) signaling in this brain region. Recent behavioral and electrophysiological evidence has suggested a functional interplay between the dopamine and cannabinoid receptor systems, although the cellular mechanisms underlying this interaction remain to be elucidated. We examined this issue by combining neuroanatomical and electrophysiological techniques in PFC of rats and mice (both genders). Using immunoelectron microscopy, we show that CB1Rs and dopamine type 2 receptors (D2Rs) colocalize at terminals of symmetrical, presumably GABAergic, synapses in the PFC. Indeed, activation of either receptor can suppress GABA release onto layer 5 pyramidal cells. Furthermore, coactivation of both receptors via repetitive afferent stimulation triggers eCB-mediated long-term depression of inhibitory transmission (I-LTD). This I-LTD is heterosynaptic in nature, requiring glutamate release to activate group I metabotropic glutamate receptors. D2Rs most likely facilitate eCB signaling at the presynaptic site as disrupting postsynaptic D2R signaling does not diminish I-LTD. Facilitation of eCB–LTD may be one mechanism by which DA modulates neuronal activity in the PFC and regulates PFC-mediated behaviorin vivo.
A Specific Requirement of Arc/Arg3.1 for Visual Experience-Induced Homeostatic Synaptic Plasticity in Mouse Primary Visual Cortex
Authors: Gao Ming , Sossa Kenneth , Song Lihua , Errington Lauren , Cummings Laurel , Hwang Hongik , Kuhl Dietmar , Worley Paul , Lee Hey-Kyoung
Published: May 2010

Visual experience scales down excitatory synapses in the superficial layers of visual cortex in a process that provides anin vivoparadigm of homeostatic synaptic scaling. Experience-induced increases in neural activity rapidly upregulates mRNAs of immediate early genes involved in synaptic plasticity, one of which is Arc (activity-regulated cytoskeleton protein or Arg3.1). Cell biological studies indicate that Arc/Arg3.1 protein functions to recruit endocytic machinery for AMPA receptor internalization, and this action, together with its activity-dependent expression, rationalizes a role for Arc/Arg3.1 in homeostatic synaptic scaling. Here, we investigated the role of Arc/Arg3.1 in homeostatic scalingin vivoby examining experience-dependent development of layer 2/3 neurons in the visual cortex of Arc/Arg3.1 knock-out (KO) mice. Arc/Arg3.1 KOs show minimal changes in basal and developmental regulation of excitatory synaptic strengths but display a profound deficit in homeostatic regulation of excitatory synapses by visual experience. As additional evidence of specificity, we found that the visual experience-induced regulation of inhibitory synapses is normal, although the basal inhibitory synaptic strength is increased in the Arc/Arg3.1 KOs. Our results demonstrate that Arc/Arg3.1 plays a selective role in regulating visual experience-dependent homeostatic plasticity of excitatory synaptic transmissionin vivo.
Mental Imagery of Self-Location during Spontaneous and Active Self–Other Interactions: An Electrical Neuroimaging Study
Authors: Thirioux Bérangère , Mercier Manuel R. , Jorland Gérard , Berthoz Alain , Blanke Olaf
Published: May 2010

Substantial data from the cognitive neurosciences point to the importance of bodily processing for the development of a comprehensive theory of the self. A key aspect of the bodily self is self-location, the experience that the self is localized at a specific position in space within one's bodily borders (embodied self-location). Although the neural mechanisms of self-location have been studied by manipulating the spatial location of one's visual perspective during mental imagery, such experiments were conducted in constrained, explicit, and unecological contexts such as explicit instructions in a prone/seated position, although most human interactions occur spontaneously while standing/walking. Using a motor paradigm, we investigated the behavioral and neural mechanisms of spontaneous self-location and mental body transformations during active human interaction. Using own-body imagery using spontaneous and explicit changes in self-location in standing participants, we report that spontaneous interactions with an avatar are neurally indistinguishable from explicit own-body transformation with disembodied self-location but differ from explicit own-body transformation with embodied self-location at 400–600 ms after stimulus onset. We discuss these findings with respect to the neural mechanisms of perspective-taking and self-location in spontaneous human interaction.