Motor protein proves to be breathing protein

But this is now refuted by new findings by Uppsala University researchers who show that the protein is absolutely crucial to our respiration. The study is being published in the latest issue of the highly prestigious Journal of Neuroscience.

“These were entirely unexpected and extremely exciting findings. They clearly show that the protein we suspected was so important to mobility patterns in fact were not,” says Klas Kullander, a researcher in genetic developmental biology at Uppsala University and lead author of the study.

His research deals with the use of genetically modified mice to identify nerve circuits that govern various bodily functions. Above all, he has focused on motor movement, which is relatively simple, since it all starts in the spinal cord.

“It constitutes a sort of ‘mini-brain’ that produces rhythms and coordinates movements without any input from the brain,” Klas Kullander explains.

The protein VGLUT2 exists in two commonly occurring variants and is used in the communication between nerve cells. This protein is necessary for glutamate, which exists in tiny swellings in the ends of the nerve cells (synapses), to be released to relay signals from one nerve cell to the next. One variant, VGLUT1, has been shown by other scientists to be of no significance in motor patterns. Mice without this gene can move but evince certain other neurological defects. Using this fact as a point of departure, the Uppsala team examined the other variant instead, which moreover is much more prevalent in the spinal cord. It proved to be not at all important in movement patterns, but rather for breathing. As early as the fetal period, the musculature of the lungs is exercised by “water breathing.” But in mouse embryos without VGLUT2 the lungs were never used and therefore were unable to breathe air when the mice were born.

“This possibility of knocking out certain specific genes in mice, which are genetically very similar to humans, provides us with new and important genetic knowledge about the functions of the nervous system that may lead to tremendous medical advances,” says Klas Kullander.