University of Maryland study uses rat whiskers to help break the brain’s code
Rats would be lost, if not blind, without their whiskers. Just as humans use sight, rats rely on their whiskers to navigate, search for food, find a mate, and sense the presence of predators. Now those same whiskers are helping scientists at the University of Maryland School of Medicine to understand the complex language used by the brain to interpret stimulation from the outside world. Researchers hope that learning this neural code might someday lead to the development of new treatments for neurological injuries or illness.
The study, published in the June 25 issue of the journal Science, measured how individual neurons within the brain responded to whisker stimulation. The whisker twitches, controlled by the researchers, produced a specific firing pattern in the neurons, which could be illustrated by spikes on a graph. The spike pattern represents the message received by the brain as a result of the whisker movement.
“From a single pattern of spikes, we can tell you exactly what happened to the whisker,” says Asaf Keller, Ph.D., professor of anatomy and neurobiology at the University of Maryland School of Medicine, and the primary investigator. “By understanding the exact relationship between the stimulus and the brain activity, we can begin to understand the complex code by which the brain operates.”
The ability to detect general brain activity in response to movement is not new, but the University of Maryland School of Medicine research goes a significant step further by showing a direct correlation between the stimulus and the corresponding neural activity at the cellular level. By reading the firing pattern, researchers can predict what the stimulus was.
“Learning a neural code is like learning a foreign language,” says Lauren Jones of the Program in Neuroscience at the University of Maryland School of Medicine and co-author of the study. “We have to start small and learn the alphabet before we can understand words and sentences. Once we know the language, we will be able to converse with the brain.”
By understanding the code, doctors may one day be able to use the brain’s own language to bridge neurological gaps resulting from injury or illness. For example, says Dr. Keller, “the neural code could be used to operate a robotic arm for a person who has lost a limb. Or, the code could be used to stimulate the brain of a blind person to simulate or restore sight. Such advances may be decades away, but beginning to understand the neural code is the first step.”
Researchers used a computer controlled device to stimulate the whiskers in complex patterns. Microscopic electrodes were used to record the electrical activity from the individual neurons that responded to the stimulated whisker. The scientists then analyzed the responses to predict whisker movements based on the electrical activity of a single neuron.
For patient inquiries, call 1-800-492-5538 or click here to make an appointment.