Proceedings of the Natural Academy of Sciences

Proceedings of the National Academy of Sciences RSS feed -- current issue
  • Crossmodal working memory in monkey frontal cortex [Neuroscience]
    [Jan 2015]

    Previous studies have shown that neurons of monkey dorsolateral prefrontal cortex (DLPFC) integrate information across modalities and maintain it throughout the delay period of working-memory (WM) tasks. However, the mechanisms of this temporal integration in the DLPFC are still poorly understood. In the present study, to further elucidate the role...
    Categories: Journal Articles
  • Drosophila thermotaxis: Determinants of behavior [Neuroscience]
    [Jan 2015]

    Complex animal behaviors are built from dynamical relationships between sensory inputs, neuronal activity, and motor outputs in patterns with strategic value. Connecting these patterns illuminates how nervous systems compute behavior. Here, we study Drosophila larva navigation up temperature gradients toward preferred temperatures (positive thermotaxis). By tracking the movements of animals...
    Categories: Journal Articles
  • Extinction can be learned without retrieval [Psychological and Cognitive Sciences]
    [Jan 2015]

    In the present study we test the hypothesis that extinction is not a consequence of retrieval in unreinforced conditioned stimulus (CS) presentation but the mere perception of the CS in the absence of a conditioned response. Animals with cannulae implanted in the CA1 region of hippocampus were subjected to extinction...
    Categories: Journal Articles
  • Hematopoietic IKBKE and NLRP3 inflammasome priming [Immunology and Inflammation]
    [Jan 2015]

    Obesity increases the risk of developing life-threatening metabolic diseases including cardiovascular disease, fatty liver disease, diabetes, and cancer. Efforts to curb the global obesity epidemic and its impact have proven unsuccessful in part by a limited understanding of these chronic progressive diseases. It is clear that low-grade chronic inflammation, or...
    Categories: Journal Articles
  • Inducible RNAi in naive CD8+ T cells in vivo [Immunology and Inflammation]
    [Jan 2015]

    The differentiation of effector CD8+ T cells is critical for the development of protective responses to pathogens and for effective vaccines. In the first few hours after activation, naive CD8+ T cells initiate a transcriptional program that leads to the formation of effector and memory T cells, but the regulation...
    Categories: Journal Articles
  • Mucosal CD4+ T cells and SIV transmission [Immunology and Inflammation]
    [Jan 2015]

    An effective T-cell–based AIDS vaccine should induce strong HIV-specific CD8+ T cells in mucosal tissues without increasing the availability of target cells for the virus. Here, we evaluated five immunization strategies that include Human adenovirus-5 (AdHu5), Chimpanzee adenovirus-6 (AdC6) or -7 (AdC7), Vaccinia virus (VV), and DNA given by electroporation...
    Categories: Journal Articles
  • CTLA-4 regulates TFH generation [Immunology and Inflammation]
    [Jan 2015]

    Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is an essential regulator of T-cell responses, and its absence precipitates lethal T-cell hyperactivity. However, whether CTLA-4 acts simply to veto the activation of certain clones or plays a more nuanced role in shaping the quality of T-cell responses is not clear. Here we report that...
    Categories: Journal Articles
  • Tumor-tropic iPSC-MSCs are safer than BM-MSCs [Medical Sciences]
    [Jan 2015]

    Mesenchymal stem or stromal cells (MSCs) have many potential therapeutic applications including therapies for cancers and tissue damages caused by cancers or radical cancer treatments. However, tissue-derived MSCs such as bone marrow MSCs (BM-MSCs) may promote cancer progression and have considerable donor variations and limited expandability. These issues hinder the...
    Categories: Journal Articles
  • Beneficial metabolic actions of omega-3 epoxides [Medical Sciences]
    [Jan 2015]

    Soluble epoxide hydrolase (sEH) is an emerging therapeutic target in a number of diseases that have inflammation as a common underlying cause. sEH limits tissue levels of cytochrome P450 (CYP) epoxides derived from omega-6 and omega-3 polyunsaturated fatty acids (PUFA) by converting these antiinflammatory mediators into their less active diols....
    Categories: Journal Articles
  • Red meat-derived glycan promotes cancer [Medical Sciences]
    [Jan 2015]

    A well known, epidemiologically reproducible risk factor for human carcinomas is the long-term consumption of “red meat” of mammalian origin. Although multiple theories have attempted to explain this human-specific association, none have been conclusively proven. We used an improved method to survey common foods for free and glycosidically bound forms...
    Categories: Journal Articles
  • H9N2 evolution in the genesis of H7N9 virus [Microbiology]
    [Jan 2015]

    The emergence of human infection with a novel H7N9 influenza virus in China raises a pandemic concern. Chicken H9N2 viruses provided all six of the novel reassortant’s internal genes. However, it is not fully understood how the prevalence and evolution of these H9N2 chicken viruses facilitated the genesis of the...
    Categories: Journal Articles
  • EBNA3A genome landscape [Microbiology]
    [Jan 2015]

    Epstein–Barr Virus (EBV) conversion of B-lymphocytes to Lymphoblastoid Cell Lines (LCLs) requires four EBV nuclear antigen (EBNA) oncoproteins: EBNA2, EBNALP, EBNA3A, and EBNA3C. EBNA2 and EBNALP associate with EBV and cell enhancers, up-regulate the EBNA promoter, MYC, and EBV Latent infection Membrane Proteins (LMPs), which up-regulate BCL2 to protect EBV-infected...
    Categories: Journal Articles
  • Direct measurement of redox stress in Salmonella [Microbiology]
    [Jan 2015]

    Many significant bacterial pathogens have evolved virulence mechanisms to evade degradation and exposure to reactive oxygen (ROS) and reactive nitrogen species (RNS), allowing them to survive and replicate inside their hosts. Due to the highly reactive and short-lived nature of ROS and RNS, combined with limitations of conventional detection agents,...
    Categories: Journal Articles
  • Rhythmic, glycan-driven acidification in symbiosis [Microbiology]
    [Jan 2015]

    Glycans have emerged as critical determinants of immune maturation, microbial nutrition, and host health in diverse symbioses. In this study, we asked how cyclic delivery of a single host-derived glycan contributes to the dynamic stability of the mutualism between the squid Euprymna scolopes and its specific, bioluminescent symbiont, Vibrio fischeri....
    Categories: Journal Articles
  • Dialkylresorcinols as signaling molecules [Microbiology]
    [Jan 2015]

    It is well recognized that bacteria communicate via small diffusible molecules, a process termed quorum sensing. The best understood quorum sensing systems are those that use acylated homoserine lactones (AHLs) for communication. The prototype of those systems consists of a LuxI-like AHL synthase and a cognate LuxR receptor that detects...
    Categories: Journal Articles
  • Distinct reward signals in Drosophila [Neuroscience]
    [Jan 2015]

    Drosophila melanogaster can acquire a stable appetitive olfactory memory when the presentation of a sugar reward and an odor are paired. However, the neuronal mechanisms by which a single training induces long-term memory are poorly understood. Here we show that two distinct subsets of dopamine neurons in the fly brain...
    Categories: Journal Articles
  • Activation of the PPT or LDT induces REM sleep [Neuroscience]
    [Jan 2015]

    Rapid eye movement (REM) sleep is an important component of the natural sleep/wake cycle, yet the mechanisms that regulate REM sleep remain incompletely understood. Cholinergic neurons in the mesopontine tegmentum have been implicated in REM sleep regulation, but lesions of this area have had varying effects on REM sleep. Therefore,...
    Categories: Journal Articles
  • Odorant receptors as mechanosensors [Neuroscience]
    [Jan 2015]

    Mechanosensitive cells are essential for organisms to sense the external and internal environments, and a variety of molecules have been implicated as mechanical sensors. Here we report that odorant receptors (ORs), a large family of G protein-coupled receptors, underlie the responses to both chemical and mechanical stimuli in mouse olfactory...
    Categories: Journal Articles
  • Arcuate GABA innervation of GnRH neurons in PCOS [Neuroscience]
    [Jan 2015]

    Polycystic ovarian syndrome (PCOS), the leading cause of female infertility, is associated with an increase in luteinizing hormone (LH) pulse frequency, implicating abnormal steroid hormone feedback to gonadotropin-releasing hormone (GnRH) neurons. This study investigated whether modifications in the synaptically connected neuronal network of GnRH neurons could account for this pathology....
    Categories: Journal Articles
  • Stac regulation of Ca2+ channels [Physiology]
    [Jan 2015]

    Excitation–contraction (EC) coupling in skeletal muscle depends upon trafficking of CaV1.1, the principal subunit of the dihydropyridine receptor (DHPR) (L-type Ca2+ channel), to plasma membrane regions at which the DHPRs interact with type 1 ryanodine receptors (RyR1) in the sarcoplasmic reticulum. A distinctive feature of this trafficking is that CaV1.1...
    Categories: Journal Articles