Much like the electrical wiring in your house, the nerves in your body need to be completely covered by a layer of insulation to work properly.
Instead of red, white or black plastic, however, the wiring in the nervous system is protected by layers of an insulating protein called myelin. These layers increase the speed that nerve impulses travel throughout the brain and the body. The critical role they play is dramatically illustrated by the symptoms of multiple sclerosis, which is caused by lesions that destroy myelin. These include: blindness, muscle weakness and paralysis, loss of coordination, stuttering, pain and burning sensations, impotence, memory loss, depression and dementia.
The formation of myelin sheaths during development requires a complex choreography generally considered to be one of nature's most spectacular examples of the interaction between different kinds of cells. Now, a group of Vanderbilt researchers has successfully produced movies that provide the first direct view of the initial stage of this process: the period when the cells that ultimately produce the myelin sheathing spread throughout the developing nervous system. The results were published online in the journal Nature Neuroscience on Nov. 12 and should aid in the design of new therapies to promote the repair of this protective layer following disease or injury.
"We discovered that this process is far more dynamic than anyone had dreamed," says Bruce Appel, the associate professor of biological sciences and Kennedy Center investigator who headed up the study.
In the central nervous system, the myelin membranes are produced by cells called oligodendrocytes. These cells must be distributed uniformly along axons the long, wire-like extensions from neurons that carry nerve impulses so that the membranes, which wrap the nerve fibers like millions of microscopic pieces of electrician's tape, can cover the axons completely and uniformly. The wra
Contact: David F. Salisbury