Author: Gowda Shilpa
Date: July 2007
Researchers from the Weizmann Institute of Science in Israel collaborated with the Department of Neurology at the University of Pennsylvania and the Department of Neuroscience at the University of Connecticut to investigate the types of cell-to-cell interactions that play a role in myelination. The results published this week in Nature Neuroscience reported that an interaction between two molecules on axons and "helper" Schwann cells is necessary for myelination, with important implications for the treatment of the host of human diseases affected by the loss of myelin.
Myelination refers to the coating of axons, or the part of the neuron extending away from the cell body, with the protein myelin, which helps to speed up nerve impulses. As nerve impulses regulate vital bodily functions, the effects of the loss of myelin are severe; indeed such loss can cause several neurodegenerative autoimmune diseases, such as multiple sclerosis (MS), leading to paralysis.
The researchers identified two types of molecules mediating the interaction between Schwann cells and axons: Necl1 and Necl4. Necl1 was found to be on the axon, while Necl4 was found to be on the Schwann cell. The researchers ran experiments by disrupting the interaction between Necl1 and Necl4, each time preventing myelination. This suggests a vital role for the interaction of Necl1 and Necl4 in promoting myelination. It should be noted however, as the helper "Schwann" cells are found mainly in the peripheral nervous system (PNS), or the part of the nervous system in the body that does not include the brain or the spinal cord, the finding applies to only these areas.
The findings only spark further research according to Ivo Spiegel, the graduate student at the Weizmann Institute, who is also the first author of the paper published in Nature Neuroscience. "Our findings so far just indicate that we found a molecule that seems to play an important role in Schwann cell-axon interactions and myelination in the PNS--now we of course want to know what exactly this molecule does during myelination and how it does that," the scientist wrote in an e-mail to JYI. In other words, the scientists hope to further investigate the specific molecular interactions between Necl1 and Necl4, so as to better understand their role in allowing interaction between axons and Schwann cells.
- By Shilpa Gowda.