Scientists at Washington University in St. Louis, StanfordUniversity and Columbia University have shown that the motorcortex's effects on movement can be much more easily understood bylooking at groups of motor cortex neurons instead of individualnerve cells. In the study, scientists identified rhythmic braincell firing patterns coordinated across populations of neurons inthe motor cortex. They linked those patterns to different kinds ofshoulder muscle movements. "Populations of neurons in the motor cortex oscillate inbeautiful, coordinated ways," says co-first author JohnCunningham, PhD, assistant professor of biomedical engineering atWashington University in St. Louis. "These patterns advanceour understanding of the brain's control of movement, which iscritical for understanding disorders that affect movement and forcreating therapies that can restore movement." Until now, scientists had based their studies of the motor cortexon decades-old insights into the workings of the visual cortex. Inthis region, orientation, brightness and other characteristics ofobjects in the visual field are encoded by individual nerve cells. However, researchers could not detect a similar direct encoding ofcomponents of movement in individual nerve cells of the motorcortex. "We just couldn't look at an arm movement and use that toreliably predict what individual neurons in the motor cortex hadbeen doing to produce that movement," Cunningham says. For the new study, conducted at Stanford University, scientistsmonitored motor cortex activity as primates reached for a target indifferent ways. They showed that the motor cortex generatedpatterns of rhythmic nerve cell impulses. "Finding these brain rhythms surprised us a bit, as thereaches themselves were not rhythmic," says co-first authorMark Churchland, PhD, who was a postdoctoral researcher at Stanfordat the time of the study and is now assistant professor ofneuroscience at Columbia University. "In fact, they weredecidedly arrhythmic, and yet underlying it all were theseunmistakable patterns." Cunningham compares the resulting picture of motor cortex functionto an automobile engine. The engine's parts are difficult tounderstand in isolation but work toward a common goal, thegeneration of motion. "If you saw a piston or a spark plug by itself, would you beable to explain how it makes a car move?" Cunningham asks."Motor-cortex neurons are like that, too -- they areunderstandable only in the context of the whole." Researchers are applying their new approach to understanding otherpuzzling aspects of motor cortex function. "With this model, the seemingly complex system that is themotor cortex can now be at least partially understood in morestraightforward terms," says senior author Krishna Shenoy,PhD, associate professor of electrical engineering at Stanford. We are high quality suppliers, our products such as China Bag Packaging Machines , China Screw Cap Machine for oversee buyer. To know more, please visits Piston Filling Machine.
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