Crohn’s disease is a chronic relapsing inflammatory disorder of the intestinal tract that affects an estimated 0.15% of people in the developed world. Common symptoms include abdominal pain and diarrhea, but the disorder is often associated with debilitating clinical complications. Researchers from the University of Liège, Belgium, have now uncovered an important clue to the susceptibility of individuals to this disease.

Serotonin is a major signaling chemical in the brain, and it has long been thought to be involved in aggressive behavior in a wide variety of animals as well as in humans. Another brain chemical signal, neuropeptide Y (known as neuropeptide F in invertebrates), is also known to affect an array of behaviors in many species, including territoriality in mice. A new study by Drs. Herman Dierick and Ralph Greenspan of The Neurosciences Institute in San Diego shows that these two chemicals also regulate aggression in the fruit fly, Drosophila melanogaster.

Mayo Clinic researchers, along with collaborators from the National Institutes of Health (NIH) and University of Oslo, Norway, have discovered that a miscue of the body’s genetic repair system may cause Huntington’s disease, a fatal condition that affects 30,000 Americans annually by destroying their nervous system. Until now, no one knew how Huntington’s begins, only that it is incurable. The findings appear in the online issue of the journal Nature.

The most recent census of mountain gorillas in Uganda’s Bwindi Impenetrable National Park—one of only two places in the world where the rare gorillas exist—has found that the population has increased by 6 percent since the last census in 2002, according to the Uganda Wildlife Authority, the Wildlife Conservation Society, the Max Planck Institute of Anthropology and other groups that participated in the effort.

Runners in today's London Marathon may be tempted to down several litres of water to keep their cool and achieve their best time, but large fluid intake does not achieve either, according to a sports scientist from the University of Exeter.

With today's temperatures expected to reach 19 degrees, the average runner will potentially lose almost a litre of sweat every hour and reach a body temperature of over 39 degrees, two degrees above normal. The sporting community has long assumed that drinking large amounts of water helps to keep the body's temperature down, which improves performance. A recent study led by Dr Chris Byrne of the University of Exeter shows that the level of fluid intake has absolutely no effect on body temperature or performance.

Scientists are questioning whether peer review, the internationally accepted form of scientific critique, is able to meet the challenges posed by the rapid changes in the research landscape. A report published by the European Science Foundation (ESF) has showcased a number of options that could lead to a greater openness to innovative research.

The report "Peer review: its present and future states", which draws on ideas from an international conference in Prague in October 2006, reflects some concern on the shortcomings of peer review while outlines some possible measures to cope with them.

Researchers of the heart and headaches at Thomas Jefferson University Hospital are combining efforts to determine if a common heart defect may be the cause of some forms of migraine headaches.

Investigators from the Jefferson Heart Institute and the Jefferson Headache Center are enrolling participants in a blinded study to determine if closing a Patent Foramen Ovale (PFO), a small hole or flap that can allow blood to flow between the right and left sides of the heart, can stop migraines. In newborns, the PFO closes at or shortly after birth, but in 20 percent of adults the gap remains open to some degree.

Contrary to popular belief, lemmings do not commit mass suicide by leaping off of cliffs into the sea. In fact, they are quite fond of staying alive. A bigger threat to the rodents is climate change, which could deprive them of the snow they need for homes and lock up their food in ice, according to the Wildlife Conservation Society, which is launching a study to examine how these tiny but important players in the ecological health of the far North will fare in the age of global warming.

The rise of the central nervous system (CNS) in animal evolution has puzzled scientists for centuries. Vertebrates, insects and worms evolved from the same ancestor, but their CNSs are different and were thought to have evolved only after their lineages had split during evolution. Researchers from the European Molecular Biology Laboratory (EMBL) in Heidelberg now reveal that the vertebrate nervous system is probably much older than expected. The study, which is published in the current issue of Cell, suggests that the last common ancestor of vertebrates, insects and worms already had a centralised nervous system resembling that of vertebrates today.