When the eye tracks a birds flight across the sky, the visual experience is normally smooth, without interruption. But underlying this behavior is a complex coordination of neurons that has remained mysterious to scientists. Now, UCSF researchers have broken ground in understanding how the brain generates this tracking motion, a finding that offers a window, they say, into how neurons orchestrate all of the bodys movements.
The study, reported in the April 24 issue of Neuron, reveals that individual neurons do not fire independently across the entire duration of a motor function as traditionally thought. Rather, they coordinate their activity with other neurons, each firing at a particular moment in time.
Scientists have known that neurons that connect to muscles initiate movement in a coordinated fashion. But they have not known how the neurons we are studying which coordinate these front-line neurons -- commit the brain to move the eyes, says co-lead author David Schoppik, PhD, who conducted the study while a doctoral candidate in the laboratory of senior author Stephen Lisberger, PhD, at the University of California, San Francisco.
For decades, scientists have been asking, Do the signals involve a handful of neurons or thousands" What is the nature of the commands" The classical understanding has been that one class of neuron is responsible for one movement, such as generating eye movement to the left, and that it remains active across the entire duration of a behavior, he says.
The new findings suggest a totally different way of looking at how movement is controlled across time, says Lisberger, a Howard Hughes Medical Institute Investigator at UCSF, where he is professor of physiology, director of the W.M. Keck Foundation Center for Integrative Neuroscience, and co-director of the Sloan Center for Theoretical Neurobiology.
The findings, the researchers say, could inform efforts to develop neural prosthetics t
|Contact: Jennifer OBrien|
University of California - San Francisco