Insight into the brain

The parts of the brain that enable you to do a familiar task are different from those that learn that task, a new study confirms.

School of Medicine researchers reached this conclusion after obtaining positron emission tomography (PET) images of people tracing maze patterns. PET is one of the techniques that can reveal which areas of the brain are active.

"Our volunteers used some areas of the brain to learn the maze task but shifted to other areas after practice," said lead researcher Steven E. Petersen, Ph.D., professor of neurology, neurobiology and radiology.

The researchers reported their results in the October issue of the Journal of Neurophysiology. Research assistant professor Hanneke van Mier, Ph.D., is first author.

Thirty-two right-handed volunteers took part in the study. They had to move a pen through cut-out mazes while keeping their eyes closed. Half traced with the left hand, half with the right.

When the volunteers first traced a maze, they moved the pen slowly and made many false turns. During this learning period, parts of the brain called the right premotor cortex, the right parietal cortex and the left cerebellum became active, PET images revealed.

After 10 minutes of practice, the volunteers provided another set of images. As they moved the pen through the maze quickly and without making errors, the supplementary motor area, near the junction of the brain's two hemispheres, became active. The areas that were active during learning were quiescent once the volunteers had gained expertise.

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Avioli and research team to study communication between bone cells

A research team led by Louis V. Avioli, M.D., the Shoenberg Professor of Medicine and professor of orthopedic surgery, has received a four-year $5 million program project grant from the National Institute of Arthritis and Musculoskeletal Diseases. This grant will allow four teams of investigators to continue studying the biological control of bone cells that maintain a healthy skeleton.

The integrity of the skeleton relies on complex interactions in the bone centered around cells called osteoclasts and osteoblasts. Osteoclasts tear down aging bone, while osteoblasts work to rebuild it. When the balance between these cells is disrupted, diseases such as osteoporosis result. "Our research findings will help in developing therapies to overcome these imbalances and restore new bone formation," said Avioli, who directs the Division of Bone and Mineral Diseases at the medical school.

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Wilson to sequence intestinal pathogens

Richard K. Wilson, Ph.D., associate professor of genetics, has received a three-year $1.9 million grant from the National Institute of Allergy and Infectious Diseases. The grant will enable him to determine the DNA sequences of several Salmonella bacteria.

One member of the Salmonella family causes typhoid fever, while others cause foodborne intestinal infections called salmonellosis. About 40,000 cases of salmonellosis are reported each year in the United States, and 1,000 are fatal.

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