Catálogo de publicaciones - revistas

<jats:title>Responsible use of psychostimulants</jats:title> <jats:p> Psychostimulants have a place in the therapy of attentional disorders. However, they are also widely used off-label to enhance cognitive performance, and their mechanisms of action remain elusive. Westbrook <jats:italic>et al.</jats:italic> studied the effects of these drugs and concurrently measured striatal dopamine synthesis capacity in young, healthy participants (see the Perspective by Janes). They administered a placebo, methylphenidate (a dopamine and noradrenaline reuptake blocker), and sulpiride (a selective D2 receptor antagonist) while participants made explicit cost-benefit decisions about whether to engage in cognitive effort. Higher dopamine synthesis capacity in the caudate nucleus was associated with greater willingness to allocate cognitive effort. In addition, methylphenidate and sulpiride increased subjective values and motivation to work specifically for people with low dopamine synthesis capacity. Cognition-enhancing drugs may thus act at the motivational level rather than directly boosting cognition per se. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1362" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz5891">1362</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1300" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.abb0265">1300</jats:related-article> </jats:p>

<jats:title>PI(4)P regulates mitochondrial fission</jats:title> <jats:p> Mitochondria are dynamic intracellular organelles, the shape and number of which are regulated by various cell-signaling pathways. Mitochondrial division is driven by the recruitment of a constricting guanosine triphosphatase protein at sites of contact with the endoplasmic reticulum, but other factors, including lysosomes, are also involved. Nagashima <jats:italic>et al.</jats:italic> now document an essential role for Golgi-derived vesicles bearing a specific lipid—phosphatidylinositol 4-phosphate, or PI(4)P—in the final steps of mitochondrial division. Disruption of PI(4)P production results in mitochondrial morphological defects indicative of an inability to complete fission. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1366" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aax6089">1366</jats:related-article> </jats:p>

<jats:title>From genetics to material to behavior</jats:title> <jats:p> Introducing new genes into an organism can endow new biochemical functions or change the patterns of existing functions, but extending these manipulations to structure at the tissue level is challenging. Combining genetic engineering and polymer chemistry, Liu <jats:italic>et al.</jats:italic> directly leveraged complex cellular architectures of living organisms to synthesize, fabricate, and assemble bioelectronic materials (see the Perspective by Otto and Schmidt). An engineered enzyme expressed in genetically targeted neurons synthesized conductive polymers in tissues of freely moving animals. These polymers enabled modulation of membrane properties in specific neuron populations and manipulation of behavior in living animals. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1372" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay4866">1372</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1303" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.abb0216">1303</jats:related-article> </jats:p>

<jats:title>Choosing mates wisely</jats:title> <jats:p>Hybridization between species has long been seen as an accidental contributor to evolution in some cases and as a dead end in others. New evidence is emerging, however, that hybridization may have played important, and nonrandom, roles in adaptation. Chen and Pfennig describe just such a case where female Plains spadefoot toads preferentially choose males from another toad species, the Mexican spadefoot, as mates, but only under certain environmental conditions (see the Perspective by Zuk). The offspring of this preferred hybrid mating event have higher fitness than nonhybrids in the same environment. Thus, not only do hybrids have an advantage, but females of one species are exerting a selective influence on the other species.</jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1377" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz5109">1377</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1304" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.abb2398">1304</jats:related-article> </jats:p>

<jats:title>Macrophages cFLIP out</jats:title> <jats:p> Pathogens have evolved to survive within hosts in part by interfering with host signaling cascades. <jats:italic>Yersinia</jats:italic> bacteria use the effector protein YopJ to thwart MAP kinase signaling downstream of Toll-like receptor activation. In response to YopJ, host cells can release interleukin-1β and initiate pyroptosis by inhibition of the kinase TAK1 and subsequent caspase-8–directed cleavage of gasdermin D, a protein that forms cell membrane pores. Muendlein <jats:italic>et al.</jats:italic> report that cFLIP, a major antiapoptotic regulator, plays a central role in this process. Knockdowns of the long but not short cFLIP isoform in macrophages removes the requirement for TAK1 inhibition. Rather, deficiency of the long isoform fuels caspase-8 activation, mitochondrial complex II formation, pyroptosis, and interleukin-1β secretion in response to lipopolysaccharide alone, underscoring its importance for cell death and inflammation. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1379" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay3878">1379</jats:related-article> </jats:p>

<jats:title>Every twig and splinter used</jats:title> <jats:p> Plant-based production of commodity chemicals faces steep competition from fossil resources, which are often cheaper and easier to partition. Sustainable use of renewable resources requires strategies for converting complex and recalcitrant biomolecules into streams of chemicals with extraordinary efficiency. Liao <jats:italic>et al.</jats:italic> developed a biorefinery concept in which wood is eventually fully converted into useful chemicals: phenol, propylene, pulp amenable to ethanol production, and phenolic oligomers that can be incorporated into ink production (see the Perspective by Zhang). A life-cycle assessment and techno-economic analysis highlight the efficiency of the process and reveal the potential for such biorefinery strategies to contribute to sustainable chemicals markets. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1385" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aau1567">1385</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6484" page="1305" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.abb1463">1305</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>

<jats:p>Cryo-electron microscopy (cryo-EM) yields atomic-level structures of megacomplexes and tiny compounds. How can your lab get access to this versatile method?</jats:p>