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Frontlines Image: Anna Powers Social thinking Planning a future, knowing your limitations, following moral rules--these and other uniquely human capacities will be the focus of a research project at California Institute of Technology funded by a million dollar grant from the David and Lucile Packard Foundation. Associate Professor of philosophy Steven Quartz will lead an interdisciplinary team of social scientists and neurobiologists who will use functional magnetic resonance imaging (fMRI) techniques in their quest to define the neurological underpinnings of economic and moral decision making. This study will be among the first to investigate brain activity while subjects are engaged in complex social interactions, according to Quartz. "Given the explosion of knowledge in brain science, we are now in a position where we can expand neuroscience into social science avenues," he says. The study will look at how the brain uses what Quartz calls a symbolic self to engage in social interactions. Quartz believes that humans' ability to understand how various kinds of social roles have symbolic obligations in part distinguishes humans from other animals. "We can see rudimentary forms of these behaviors in animals, but clearly there's been something that has allowed the human brain to get reorganized in a way that allows us to engage in symbolic forms of behavior," he said. Such thinking, Quartz says, "allows us to live in a very different kind of way, unlocked from the present. All the social institutions and rules of morality that we build depend upon us having the capacity to reason about the future and engage in long-term relationships." --Laura DeFrancesco Image: Erica P. Johnson Genetic Velcro The 500,000+ copies of the 300-base DNA repeat sequence Alu that dot the human genome have been mysteries for decades, sometimes even dubbed "junk." But, the elusive sequences may provide a chromosomal Velcro® of sorts, serving as attachment points for the cohesin protein complexes that bind newly replicated chromosomes before they segregate into daughter cells. Researchers at the Wistar Institute, Philadelphia, and at the University of California, Irvine, implicated Alu "by accident," says Ramin Shiekhattar, an associate professor at Wistar, when they used chromatin immunoprecipitation experiments to trace cohesin's activity (M.-A. Hakimi et al., "A chromatin remodeling complex that loads cohesin onto human chromosomes," Nature, 418:994-8, Aug. 29, 2002). "The only place cohesin bound to the chromosome was where sequences contain Alu repeats. We looked at Alu sequences on 22 chromosomes, and more than half bound ... cohesin," he says, adding that they cannot yet rule out a role for flanking sequences. But Alu fits the bill. "These sequences are very common. Multiple bridging sites throughout the DNA would be needed for this system to work. They couldn't be unique sequences. It makes sense that one of their roles is to bind to the bridging proteins, the cohesins, to keep the replicated DNA sisters together until it is time for them to separate," he explains. --Ricki Lewis Image: Anne MacNamara The eye wire act Scientists are a step closer to understanding how the eye transmits images to the brain, according to recent findings about the complicated set of neural connections that result in vision as we know it (R. Hindges et al., "EphB forward signaling controls directional branch extension and arborization required for dorsal ventral retinotopic mapping," Neuron, 35:475-87, August 2002). The research focuses on optic axons, the neurons that grow from four different parts of the retina--left, right, top, and bottom--and terminate into corresponding visual centers in the brain. It establishes how Eph receptors control neuronal wiring from the eye to the brain's visual centers. Previous reports had established that A-class Ephs are key in mapping the optic axons on the left-right axis of the eye into the brain. Now this report shows that B-class Ephs map the axons on the up-down axis of the eye into the brain. "The information in this paper is the first molecular and genetic information showing what controls mapping on this axis," says Dennis D.M. O'Leary, molecular biologist at the Salk Institute for Biological Studies. He and his group injected fluorescent dye into the optic axons of normal mice and Eph mutant mice, and then watched the cells' path to the brain using a confocal microscope. They saw that vertical axons in mice lacking proteins EphB2 and EphB3 failed to map correctly to the brain, and the mice had impaired vision. --Jennifer Fisher Wilson Artwork: Hunter O’Reilly Life posing as art Scientists and art aficionados may disagree about eye-pleasing imagery, but Hunter O'Reilly is bringing the two sides closer. The geneticist and internationally shown artist reinterprets science as art through abstractions, digital art, and installations, known as bioart. While making a routine trip down what she calls the "wrong path on the road to discovery" during her graduate studies, O'Reilly turned frustration in the lab into muse for her canvases. "At first I was using art as an escape, but cellular forms started to evolve in my paintings." Now, as an adjunct professor of the biological sciences at the University of Wisconsin-Parkside, O'Reilly has developed a course "Biology through Art" that uses science as an artistic medium. The course outlines the basics of DNA and the diversity of life. O'Reilly also lectures on how other contemporaries have integrated biology into their compositions. For their final project, students create biological self-portraits. The class--and the artwork that inspired it--stems from O'Reilly's belief that the public needs to understand biotechnology. "I think my art helps give a different perspective on biotechnology than one would normally see," O'Reilly says. "If my art makes someone think, I think that makes it successful." --Hal Cohen Image: Digital Vision Stressed mothers: a danger for kids For the first time in humans, researchers have been able to link the impact of maternal stress during infancy with subsequent behavior problems in the first grade. Children whose mothers were depressed during the first year of life had high levels of the stress hormone cortisol. Researchers from the University of Wisconsin-Madison have reported that this makes the children vulnerable to stressful situations (M.J. Essex et al., "Maternal stress beginning in infancy may sensitize children to later stress exposure: effects on cortisol and behavior," Biological Psychiatry, in press). The specific link between cortisol and behavior is not completely understood, says Ned Kalin, professor of psychiatry at the university, "but there are hypothetical, rational explanations. The brain has cortisol receptors in strategic positions that mediate arousal and motivation." The receptors are found in the hippocampus, involved in motivation, and the prefrontal cortex, which plays key roles in problem solving and emotion regulation. "The higher cortisol levels may be altering the individual's ability to stay focused or to inhibit a response. The ability to regulate emotion is somehow disrupted," Kalin says. "The paper is very impressive for having strengthened the relationship between family stress, depression and cortisol in the kids," comments Bruce McEwen, head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology at Rockefeller University. Chronically high levels of cortisol also damage neurons in the hippocampus, and can induce "insulin resistance, the demineralization of bone, and the breakdown of muscle protein," he adds. --Harvey Black Image: Anne MacNamara Nature's second nature Math, physics, chemistry, computer science, and engineering should be incorporated into biology courses and lab experiments to the degree that "interdisciplinary thinking and work become second nature," according to a new report from the National Academy of Sciences (NAS). While most colleges already require biology majors to take math and physical science courses, faculty often do not integrate these subjects into their biology curricula. "This can result in students with a shortsighted view of the connections between all the scientific disciplines involved in the study of the biological world," the report states. But, significant challenges await faculty and administrators seeking to round out their programs. Coaxing biology departments to move in the right direction will take time, says James Gentile, NAS committee member and dean of natural sciences at Hope College, in Holland, Mich. "You need to teach people first to crawl, then to walk, and then to run." Reforms also will require cooperation from faculty, administrators, professional societies, foundations, industry, and government. "We are asking faculty to develop and teach new kinds of courses. Far-reaching changes will be tough to accomplish," says Lubert Stryer, NAS committee chair and professor of neurobiology at Stanford University. The study, "BIO 2010: Undergraduate Education to Prepare Biomedical Research Scientists," was sponsored by the National Institutes of Health and the Howard Hughes Medical Institute. HHMI also plans to award $1 million (US) each to 20 US researchers in the fall of 2002 for creating innovative science curricula at the undergraduate level (hhmi.org/news/083101.html). --Ted Agres

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