New dyes created for tracking neuronal activity

Researchers have created a new type of fluorescent dye that could be used to highlight electrical activity in neuronal membranes.

These next generation dyes function by penetrating only the membrane of neurons, meaning that the dye glows brightly when the neuron fires, creating a flash that can be captured using high-speed cameras.

It is thought that this technique would make it far easier to visualise small, fast-changing voltage differences between the interior and exterior of neurons, a potentially useful means of assessing how brain cells function and interact.

Currently, the most common method of accomplishing this is by measuring the movement of calcium ions into the cell, an indirect method that offers imprecise measurements.

Study author Evan Miller from the University of California, San Diego School of Medicine said: "The new dye gives big signals but is much faster and doesn't perturb the neurons. We essentially see no lag time between the optical signal and electrodes."

This follows Harvard research from last November which involved neurons being genetically altered so they light up naturally as they fire.