March 2 (UPI) -- A new optical nanosensor is helping scientists at the University of Lausanne in Switzerland more accurately map the brain. The nanosensor more accurately tracks ionized potassium, a byproduct of neural activity.
When neurons are activated, they release ionized potassium into the space between the cells. The potassium must be diffused and reabsorbed. Scientists measure potassium levels as a proxy for brain activity.