Stimulation of Specific Neurons Enhances Recovery
Research at Stanford University examined recovery from stroke in mice, but its significance will affect future therapy for brain injuries in humans. The scientists were the first to use a relatively new technique, called “optogenetics,” for studies of the brain. They engineered mice to make a light-sensitive protein in the motor cortex of the brain. They also implanted an optical fiber so they could use light to stimulate that protein, and therefore those neurons specifically.
Stroke-impaired mice (stroke mice) that were stimulated with light recovered significantly more in tests of coordination, balance, and muscle mass than did stroke mice that were not stimulated. Unlike the only drug currently used for strokes, which works to dissolve a clot and must be given within a few hours of a clot-induced stroke, the neural stimulation was effective even five days after a stroke. There were no side effects from stimulating the brains of healthy mice in the same way.
The scientists also found that stimulated stroke mice showed better weight gain than did unstimulated stroke mice. Also, the brains of stimulated stroke mice showed enhanced blood flow, produced more natural neural growth factors, and made more of a protein that strengthens neural circuits during therapy, when compared to the brains of unstimulated stroke mice.
This research is just beginning. The objective is to identify specific neural circuits that have roles in the recovery of the brain to injury. Once the circuits are known, implants that stimulate specific neurons in humans (as is being done now to control epilepsy) and/or new therapies will enhance recovery from brain injury. (Full story)
(Clip Art compliments of Bing.)