Controls thickness of myelin, essential to nervous system speed and accuracy
March 25, 2004
A gene has been found to control the thickness of nerve insulation that increases the speed and accuracy of nervous system communication.
The finding, by a team of international researchers led by Göttingen, Germany's Galin Michailov of the Max Planck Institute of Experimental Medicine and Michael Sereda of the University of Göttingen, focused on the gene Neuregulin-1.
Nrg1 was found to determine how much of the nerve insulation substance myelin was wrapped around axons—the primary transmission lines of the nervous system.
Myelin is an electrically insulating fatty layer that surrounds the axons of many neurons, especially those in the peripheral nervous system.
Myelin facilitates the smooth, high-speed transmission of electrochemical messages between the central nervous system and the rest of the body.
When myelin is lost, these signals become distorted or blocked, causing symptoms experienced by people with such diseases as multiple sclerosis and transverse myelitis.
Using transgenic mice, Michailov and colleagues found that overexpression of Nrg1 increases myelin thickness and reduced expression of Nrg1decreases it.
More specifically, the gene determines how many layers of myelin an axon orders from insulation-wrapping Schwann cells.
These cells begin forming the myelin sheath in mammals during fetal development, wrapping around axons with as many as 100 revolutions.
The researchers say that an important future goal for this line of study is to understand how neurons regulate Nrg1 expression.
The research is reported in the journal Science.
Copyright © 2004, Betterhumans