Illuminating brain stimulation therapy

Biomedicine Stroke, the disruption in blood supply to the brain, affects approximately 15 million people worldwide each year. With few treatment options, strokes leave one third of their sufferers permanently disabled. Magnetic stimulation of the brain is one promising therapy,but it is relatively non-specific. To determine which cell types may promote recovery; Cheng et al. engineered mice to express light-activated protein receptors in their neurons. They then used light to activate specific neurons and found that while stimulating neurons in the ipsilesional primary motor cortex had no effect on healthy mice, it did help mice recover after stroke. Stimulating neurons in a targeted manner may be a promising therapy for stroke patients and cause fewer side effects. Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1404109111 (2014).