PITTSBURGH -- Whiskers provide a mouse with essential information to negotiate a burrow or detect movement that could signal a predator's presence. These stiff hairs relay sensory input to the brain, which shapes neuronal activity. In a first, studies of this system by Carnegie Mellon scientists show just how well a mouse brain can compensate when limited to sensing the world through one whisker. Published April 4 in the Journal of Neuroscience, the results should help shape future studies of sensory deprivation that results from stroke or traumatic brain injury, say the authors.
"Our findings are the first to show this degree of brain adaptability in a setting with significantly limited sensory input," said Alison Barth, assistant professor of biological sciences and a member of the Center for the Neural Basis of Cognition (CNBC). "This finding tells us that brain function is plastic, or reparable, when a sense like touch has been profoundly diminished. Plasticity is an important indicator that the brain is reorganizing to compensate for an injury or deficit."
For a decade, neuroscientists have known that the brain can increase its plasticity, or adapt, in response to injury that limits bodily motion. This latest study is the first to show such an impressive enhancement of brain activity in an animal with sensory loss. Losing sight, hearing, taste, smell or touch are common disabling side effects of traumatic brain injury and stroke.
In her study, Barth recorded brain activity in mice with various degrees of whisker removal. As a first step in her research, Barth removed all but one whisker and recorded neural activity in a brain region located on the opposite side of the animal. (Flicking a whisker on one side of a mouse stimulates a part of the brain on the animal's opposite side). Over the course of a week, Barth found that one whisker could not only stimulate a predicted cluster of neurons inside the brain; it could also
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Carnegie Mellon University