Researchers from Israel have discovered previously unknown functions of myelin, which facilitates signal transmission in the nervous system. The findings explain exactly how this substance helps maintain the high efficiency of the brain.
According to a study published in the journal Proceedings of the National Academy of Sciences (PNAS), myelin in the gray matter of the cerebral cortex serves an energy-saving function rather than accelerating communication. Scientists from Ben-Gurion University found that this protective sheath around nerve fibers reduces the brain's energy costs for signal transmission by 50 percent.
The work was conducted by doctoral student Oron Kotler under the supervision of Professor Ilya Fleidervish, in collaboration with the Soroka University Medical Center, the Weizmann Institute of Science, and New York Medical College.
Reduced energy consumption without loss of speed
By comparing thin nerve fibers with and without myelin, researchers found that the presence of the sheath does not change the speed of electrical signal transmission — in both cases, it is about 0.32 meters per second. However, myelinated axons allow 50 percent less sodium to pass through. Since neurons require energy in the form of adenosine triphosphate (ATP) to remove sodium, this halves the metabolic costs of sending signals.
The study authors note that myelin in the cerebral cortex differs from myelin in peripheral nerves. It has shorter insulated segments and flexible connections, which saves energy while maintaining normal electrical function.
Implications for medicine and technology
These findings could facilitate new research into multiple sclerosis and other diseases. Understanding how myelin damage increases the energy load on neurons may help in developing new treatments aimed at regulating energy and preserving chemical balance in cells.
Furthermore, the study results may be useful in developing energy-efficient artificial intelligence systems, demonstrating how the brain maintains high performance with low energy consumption.
Source: jns.org
