A devastating neurodegenerative disease that first appears in toddlers just as they are beginning to walk has been traced to defects in mitochondria, the 'batteries' or energy-producing power plants of cells. This finding by a team of researchers, led by investigators from the Montreal Neurological Institute and Hospital – The Neuro- at McGill University, was published in this week's issue of the Proceedings of the National Academy of Sciences of the USA (PNAS). The research, which was highlighted as "Novel & Newsworthy" by the American Society for Cell Biology (ASCB), significantly increases understanding of the disease and reveals an important common link with other neurodegenerative diseases, providing renewed hope and potential new therapeutic strategies for those affected around the world.

What happens in the brain of right-handed people if their dominant hand is immobile for two weeks? This is the question addressed in the latest study led by Professor Lutz Jäncke and the Trauma Surgery Department at Zurich University Hospital. For the study, ten right-handed people with broken upper right arms were examined. Because of the plaster or sling, the test people's right hands were restricted to little or no movement for fourteen days. Therefore they used their left hands for daily activities such as eating, brushing their teeth or writing. The participants were given two MRI brain scans: one 48 hours after injury and a second 16 days after the arm was immobilized. Based on the scans, the neuropsychologists analyzed the test people's gray and white brain matter. They calculated the thickness of the cerebral cortex and the values of the corticospinal tract and measured the fine motor skills of the left, free-moving hand.

More than 500 million years ago, single-celled organisms on the Earth's surface began forming multicellular clusters that ultimately became plants and animals. Just how that happened is a question that has eluded evolutionary biologists.