Editors' Choice

Science  01 Jan 2016:
Vol. 351, Issue 6268, pp. 38

    How brains get the full picture

    1. Peter Stern

    The brains of monkeys integrate face and body information to interpret social situations


    The visual system helps organisms make sense of their world. A network of brain areas called face patches helps monkeys identify other individuals and interpret their behavior. Fisher and Freiwald wanted to determine whether these regions only interpret face information or if they integrate body information, too. They scanned the brains of monkeys that were shown faces, bodies, faces on bodies, or faces on nonbody objects. Posterior face patches and adjacent body patches recognized faces and bodies, respectively. However, these networks could integrate face and body information to represent whole monkeys in the anterior face patches. Thus, the brain combines visual information from distinct but related objects to help organisms understand their social world.

    Proc. Natl. Acad. Sci. U.S.A. 112, 14717 (2015).


    More than one way to target a protein

    1. Valda Vinson

    Proteins have multiple binding sites that may contribute to their regulation


    The primary function of many proteins involves binding to another protein or small molecule. In some cases, however, a second molecule interacting with a distinct site on the protein regulates this primary binding. To identify such functional secondary sites, Ludlow et al. used x-ray crystallography to screen a library of molecules to detect binding to 24 protein targets. Two-thirds of the proteins had at least two binding sites. Sequence analysis of secondary sites showed that most were evolutionarily conserved, suggesting biological function. Moreover, their physicochemical properties indicated that secondary sites may be druggable. Targeting these sites could provide a way to increase protein activity in a therapeutically advantageous manner.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1518946112 (2015).


    The Drp, Drp, Drp of mitochondrial fission

    1. Stella M. Hurtley

    Mitochondria are very dynamic organelles and undergo regular fusion and fission reactions. Fission involves the dynamin GTPase Drp1, a cytosolic enzyme that is recruited to mitochondria, where it oligomerizes and contracts to cause the mitochondrial membrane to constrict. Ji et al. studied Drp1 dynamics in live cells. Contrary to current models, fission sites did not directly recruit Drp1 from the cytoplasm. Instead, mitochondria progressively added Drp1 molecules to form oligomers. Most mature Drp1 oligomers did not mediate fission. When the authors experimentally induced mitochondrial fission, actin and Drp1 accumulated sequentially at specific mitochondrial fission sites. Thus, the assembly of fission-productive Drp1 oligomers involves recruitment, maturation, and actin-dependent conversion.

    eLife 10.7554/eLife.11553 (2015).


    Asymmetrical circuits reduce anxiety

    1. Pamela J. Hines

    Brain asymmetry regulates anxiety in zebrafish


    Although fish are overall bilaterally symmetrical, the devil is in the details. For instance, in zebrafish, a part of the forebrain called the epithalamus exhibits asymmetry. However, this orientation is reversed in the brains of a small percentage of zebrafish. Facchin et al. asked whether this matters to the fish. They found that fish with brains of the minority configuration showed signs of increased anxiety when compared to their majority-configuration siblings. But their brains were not simply flipped. Within the epithalamus, neuronal axons projected in unusual patterns. The results suggest that asymmetries in how the brain processes rewards and aversions may favor neuronal circuits to organize in one way over another.

    J. Neurosci. 35, 15847 (2015).


    Peer + peer = increased learning

    1. Melissa McCartney

    In math education, the definition of “cooperative learning” is greater than the sum of these two words. Reinholz describes peer-assisted reflection (PAR) in an introductory calculus class, where students work together to attempt to solve a problem, reflect on their work, conference with a peer, and revise and submit a final solution. PAR emphasizes problem-solving processes, including explanation and justification, similar to an inquiry-based science class. The PAR model stresses peer interaction, with students analyzing their peers' work in order to develop analytic skills that they can then apply to their own learning. Student success through PAR was significant and comparable to similar active learning interventions in STEM (science, technology, engineering, and mathematics) courses. Most importantly, PAR resulted in students being less likely to drop introductory calculus.

    Int. J. Res. Undergrad. Math. Ed. 10.1007/s40753-015-0005-y (2015).


    Biogenic tools for singlecell surgery

    1. Marc S. Lavine

    Miniaturization has created a world of new medical tools, from pill-cams that can be swallowed and used to photograph the digestive tract, to tiny robots used for minimally invasive surgery. Srivastava et al. pursued this to the level of operating on single cells through the creation of microdaggers. They started with microneedles extracted from plants that are composed of porous calcium oxalate and calcium carbonate. Coating the microneedles with a layer of iron and titanium allowed their manipulation by means of a magnetic field. The tip of the microdagger could drill into a cell, and the porous nature of the needles should make it possible to preload them to deliver drugs to individual cells.

    Adv. Mat. 10.1002/adma.201504327 (2015).


    An asymmetric route to amino alcohols

    1. Jake Yeston

    Amines and alcohols are among the most common and versatile functional groups in organic chemistry. The nitroso variant of the Diels-Alder reaction is a convenient means of introducing both to the same molecule. Both ends of the N=O group form a bridge between the outer carbons in a C=C-C=C diene motif, after which the lingering N-O bond can be severed. Maji and Yamamoto present a highly selective asymmetric variant of this reaction, catalyzed by a copper complex bearing a chiral diphosphine ligand. The reaction couples a range of cyclic dienes with nitroso pyrimidines and pyridazines.

    J. Am. Chem. Soc. 10.1021/jacs.5b11273 (2015).