This month in Bio-Med Roundup:
This month’s Bio-Med Roundup is sponsored by: NEUROSCIENCE/PSYCHOLOGY Defusing the Childhood Vocabulary Explosion (3 August 2007) B. McMurray Toddlers express a burst of new words as a result of their parallel acquisition of words of varying complexity, not because they acquire a new cognitive skill. High-Speed Imaging Reveals Neurophysiological Links to Behavior in an Animal Model of Depression (10 August 2007) R. D. Airan, L. A. Meltzer, M. Roy, Y. Gong, H. Chen, K. Deisseroth Neural activity in the hippocampi of rats with depression-like symptoms reflects the degree of abnormal behavior, providing a clue to the brain circuits underlying depression. See related Perspective. Characterizing the Limits of Human Visual Awareness (10 August 2007) L. Huang, A. Treisman, H. Pashler Briefly examining a scene visually, humans can pay attention to only one color at a time but may be able to see it in multiple locations. Spatial Regulation of an E3 Ubiquitin Ligase Directs Selective Synapse Elimination (17 August 2007) M. Ding, D. Chao, G. Wang, K. Shen In developing worms, the pruning of excess synapses requires proteosome-mediated protein degradation and is selectively prevented by a neural adhesion molecule. See related Perspective. Rapid Erasure of Long-Term Memory Associations in the Cortex by an Inhibitor of PKMζ (17 August 2007) R. Shema, T. C. Sacktor, Y. Dudai Even long after consolidation of a stable memory in rats, the activity of a particular protein kinase isoform is required in the cortex for its persistence. When Fear Is Near: Threat Imminence Elicits Prefrontal–Periaqueductal Gray Shifts in Humans (24 August 2007) D. Mobbs, P. Petrovic, J. L. Marchant, D. Hassabis, N. Weiskopf, B. Seymour, R. J. Dolan, C. D. Frith Brain activity in fearful humans occurs in the cognitively advanced prefrontal cortex when the threat is far away but switches to the midbrain as the threat draws near. See related Perspective. Astrocytes Potentiate Transmitter Release at Single Hippocampal Synapses (24 August 2007) G. Perea and A. Araque Certain synapses strengthen upon coincident secretion of the neurotransmitter glutamate from a neighboring astrocyte, suggesting that astrocytes contribute to learning. The Experimental Induction of Out-of-Body Experiences (24 August 2007) H. H. Ehrsson Visual and sensory stimuli that mimic subjects viewing themselves from a distance produced a center of awareness (or sense of self) outside their bodies. Video Ergo Sum: Manipulating Bodily Self-Consciousness (24 August 2007) B. Lenggenhager, T. Tadi, T. Metzinger, O. Blanke Visual and sensory stimuli that mimic subjects viewing themselves from a distance produced a center of awareness (or sense of self) outside their bodies. Localization of a Stable Neural Correlate of Associative Memory (31 August 2007) L. G. Reijmers, B. L. Perkins, N. Matsuo, M. Mayford The neurons activated in the amygdala when a mouse learns to fear a particular location are also activated when the mouse recalls that fear. GENETICS Genome Transplantation in Bacteria: Changing One Species to Another (3 August 2007) C. Lartigue, J. I. Glass, N. Alperovich, R. Pieper, P. P. Parmar, C. A. Hutchison, III, H. O. Smith, J. C. Venter The intact DNA genome was isolated from one Mycoplasma species and transferred to another, replacing the recipient’s genome and conferring its own phenotype. Divergence of Transcription Factor Binding Sites Across Related Yeast Species (10 August 2007) A. R. Borneman, T. A. Gianoulis, Z. D. Zhang, H. Yu, J. Rozowsky, M. R. Seringhaus, L. Y. Wang, M. Gerstein, M. Snyder In yeast, gene regulatory elements evolve much more rapidly than the genes they control and so may be responsible for much of the diversity among species. See related Perspective. Human Genome Ultraconserved Elements Are Ultraselected (17 August 2007) S. Katzman, A. D. Kern, G. Bejerano, G. Fewell, L. Fulton, R. K. Wilson, S. R. Salama, D. Haussler Ultraconserved DNA sequences, unchanged in vertebrates for 300 million years, are maintained by selection four times as strong as that for coding genes. A Whole-Genome Association Study of Major Determinants for Host Control of HIV-1 (17 August 2007) J. Fellay, K. V. Shianna, D. Ge, S. Colombo, B. Ledergerber, M. Weale, K. Zhang, C. Gumbs, A. Castagna, A. Cossarizza et al. A survey of the whole human genome identifies variants in immune genes that are associated with differences in viral load during the early stages of HIV infection. CELL BIOLOGY Quantitative Mass Spectrometry Identifies Insulin Signaling Targets in C. elegans (3 August 2007) M.-Q. Dong, J. D. Venable, N. Au, T. Xu, S. K. Park, D. Cociorva, J. R. Johnson, A. Dillin, J. R. Yates, III Identifying the genetic and protein targets of the insulin signaling athway in C. elegans reveals mechanisms that potentially control the aging process. See related Perspective. Forced Unfolding of Proteins Within Cells (3 August 2007) C. P. Johnson, H.-Y. Tang, C. Carag, D. W. Speicher, D. E. Discher Fluorescent labeling of cysteines in living cells reveals how mechanical stress can cause force-induced conformational changes in cellular proteins. Augmented Wnt Signaling in a Mammalian Model of Accelerated Aging (10 August 2007) H. Liu, M. M Fergusson, R. M. Castilho, J. Liu, L. Cao, J. Chen, D. Malide, I. I. Rovira, D. Schimel, C. J. Kuo et al. Increased Wnt Signaling During Aging Alters Muscle Stem Cell Fate and Increases Fibrosis (10 August 2007) A. S. Brack, M. J. Conboy, S. Roy, M. Lee, C. J. Kuo, C. Keller, T. A. Rando In older mice, overexpression of a signaling pathway may inhibit muscle regeneration by accelerating stem cell senescence while decreasing their proliferation. Effects of Aneuploidy on Cellular Physiology and Cell Division in Haploid Yeast (17 August 2007) E. M. Torres, T. Sokolsky, C. M. Tucker, L. Y. Chan, M. Boselli, M. J. Dunham, A. Amon Yeast cells containing any extra chromosome all exhibit a similar phenotype despite the presence of supernumerary genes. See related Perspective. Detection of Near-Atmospheric Concentrations of CO2 by an Olfactory Subsystem in the Mouse (17 August 2007) J. Hu, C. Zhong, C. Ding, Q. Chi, A. Walz, P. Mombaerts, H. Matsunami, M. Luo Mice can sense near-atmospheric concentrations of CO2 using a subset of olfactory neurons that may utilize the catabolic enzyme carbonic anhydrase. BIOCHEMISTRY/STRUCTURAL BIOLOGY Mechanism of Na+/H+ Antiporting (10 August 2007) I. T. Arkin, H. Xu, M. Ø. Jensen, E. Arbely, E. R. Bennett, K. J. Bowers, E. Chow, R. O. Dror, M. P. Eastwood, R. Flitman-Tene et al. Molecular dynamics simulations of a Na+/H+ antiporter allow the proposal of an atomically detailed model for the mechanism of ion transport, pH regulation, and cation selectivity. Structure of the Membrane Protein FhaC: A Member of the Omp85-TpsB Transporter Superfamily (17 August 2007) B. Clantin, A.-S. Delattre, P. Rucktooa, N. Saint, A. C. Méli, C. Locht, F. Jacob-Dubuisson, V. Villeret Structure and Function of an Essential Component of the Outer Membrane Protein Assembly Machine (17 August 2007) S. Kim, J. C. Malinverni, P. Sliz, T. J. Silhavy, S. C. Harrison, D. Kahne Two structures of bacterial outer membrane proteins reveal how the polypeptide transport–associated domain can bind and transport diverse cellular proteins. See related Perspective. Anatomy and Dynamics of a Supramolecular Membrane Protein Cluster (24 August 2007) J. J. Sieber, K. I. Willig, C. Kutzner, C. Gerding-Reimers, B. Harke, G. Donnert, B. Rammner, C. Eggeling, S. W. Hell, H. Grubmüller, T. Lang Clusters of about 75 molecules of the membrane protein syntaxin result from weak attraction among the proteins balanced by steric repulsion induced by crowding. See related Perspective. Domain Architecture of Pyruvate Carboxylase, a Biotin-Dependent Multifunctional Enzyme (24 August 2007) M. St. Maurice, L. Reinhardt, K. H. Surinya, P. V. Attwood, J. C. Wallace, W. W. Cleland, I. Rayment Biotin activation of the enzyme pyruvate carboxylase decreases the distance between the two active sites, facilitating the transfer of a carboxyl group from one to the other. Replication Origin Recognition and Deformation by a Heterodimeric Archaeal Orc1 Complex (31 August 2007) E. L. C. Dueber, J. E. Corn, S. D. Bell, J. M. Berger Structural Basis of DNA Replication Origin Recognition by an ORC Protein (31 August 2007) M. Gaudier, B. S. Schuwirth, S. L. Westcott, D. B. Wigley The DNA-bound structures of two protein factors that initiate DNA replication in archaea show how they dramatically deform the DNA duplex, priming it for unwinding. See related Perspective. Structure of a Tyrosine Phosphatase Adhesive Interaction Reveals a Spacer-Clamp Mechanism (31 August 2007) This month’s Bio-Med Roundup is sponsored by: |