5:32 p.m. ET (2242 GMT) November 5, 1999
NEW YORK, Nov 05 (Reuters Health) - The success of a new technique in animal studies suggests that transplanted brain cells may one day be used to treat nervous system disorders such as multiple sclerosis, according to researchers.
In disease such as multiple sclerosis, areas of the central nervous system - the brain and spinal cord - become demyelinated, that is the myelin sheaths that enhance the conduction of nerve impulses are lost. The result is symptoms that include muscle weakness, visual disturbances, lack of coordination, and abnormal skin sensations.
Investigators at the University of Wisconsin School of Veterinary Medicine and the Promega Corporation, both in Madison, and the University of Bonn Medical Center in Germany, report that they have induced certain myelin-deficient rats to manufacture the material by placing undifferentiated progenitor or 'parent' brain cells into the ventricles of these animals during brain development. These cells give rise to specialized types of cells that support nerve functions.
From the ventricles - the cavities within the brain that are filled with cerebrospinal fluid - these cells "migrated into the white and gray matter and produced myelin at widespread sites,'' Dr. Randall D. Learish and colleagues write in the November Annals of Neurology.
The researchers also observed that some progenitor cells proceeded to differentiate into the myelin-producing oligodendrocyte cells when introduced into normal fetal rat brains as well.
Learish and his team write that utilizing the ventricular route to seed the brain with myelin-producing cells makes sense. "Access to (the ventricular system) is straightforward, numerous cells have been shown to survive when transplanted into the ventricles, but most important, the flow of cerebrospinal fluid could potentially distribute the cells widely throughout the central nervous system,'' they explain.
A ventricular therapeutic avenue becomes particularly attractive in the case of multiple sclerosis, for example, since the lesions associated with that disorder are often situated close to the ventricles.
However, in a statement, researcher Dr. Ian Duncan of the University of Wisconsin School of Veterinary Medicine stressed that this work is at a very early stage.
"We need to be able to promote migration of a greater number of cells into the brain and have them myelinate many more nerve fibers,'' said Duncan. "We also need to show that we can achieve similar results in the adult brain.''
SOURCE: Annals of Neurology 1999;46:716-722.