CHICAGO (April 8, 2002) -- A person suffering from traumatic brain injury often loses cortical function, which controls their ability for conscious mental processing and the ability to obtain body equilibrium. Researchers have used a reproducible model system in rats to better understand the restoration of adult cortical function following traumatic brain injury. The study, "Immortalized Progenitor Cells Restore Barrel Cortex Function After Focal Injury," will be presented by Wylie H. Zhu, MD, PhD, David A. Carter, MD and Charles J. Hodge, Jr. MD, from the Upstate Medical University at Syracuse, on Tuesday, April 9, from 4:30 to 4:45 p.m., during the 70th Annual Meeting of the American Association of Neurological Surgeons (AANS).

The study uses rats as the reproducible model system. Adult rat whiskers are arranged in rows and columns. Their corresponding cortex (outer layer of the brain) is arranged in the same way. Each whisker has its own designated slot or space in the cortex. This slot is commonly called a barrel, because its shape resembles a barrel when viewed from the side (barrel cortex). Focusing on a single barrel, researchers used high-resolution intrinsic signal optical imaging (ISI) for testing the reflective signal of cerebral cortex. This testing helped to evaluate changes in cortical function after injury. One week following injury, researchers re-evaluated the function of the barrel cortex using ISI.

Following the re-evaluation, researchers grafted neuronal progenitor cells from mice into the injured barrel. Eight weeks after surgically implanting or grafting, the barrel cortex function was again studied using ISI. Control rats received an injection of culture medium instead of cell graft.

Researchers noted that at one-week post-injury, the injured barrel was functionally inactive. However, eight weeks after cell grafting, the altered area returned to its pre-injury state of function, with significant decrease in the functionally inactive area affecting the brain. In summary, the cell grafting technique helped to restore brain function.

"Although these preliminary results are very encouraging, much remains to be understood in cell transplantation before it can be successful in clinical use," said Wylie H. Zhu, MD PhD, an author of the study and member of the AANS. "The ongoing investigations are focused on conditions or factors that contribute to graft survival, migration and differentiation, as well as anatomical repair of injured cortex."

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons is a scientific and educational association with nearly 5,500 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system including the spinal column, spinal cord, brain and peripheral nerves.