NeuroImage: multiplexing in the visual brain

Imagine sitting in a train at the railway station looking outside: without analysing the relative motion of object contours across many different locations at the same time, it is often difficult to decide whether it's your train that starts moving, or the one at the opposite track.

How is such diverse information conveyed simultaneously through the network of millions of activated nerve cells in the visual brain?

''Neurons synchronise with different partners at different frequencies'' says Dr Dirk Jancke, Neuroscientist at the Ruhr-University in Bochum, Germany. A new imaging technique enables showing that such functioning results in distinct activity patterns overlaid in primary visual cortex.

These patterns individually signal motion direction, speed, and orientation of object contours within the same network at the same time.

Together with colleagues at the University of Osnabrück, the Bochum scientists successfully visualised such brain multiplexing using a modern real-time optical imaging method that exploits a specific voltage-sensitive dye.

Imaging with voltage-sensitive dye: A method to capture real-time brain dynamics
The dye incorporates in the brain cells' membrane and changes fluorescence whenever these receive or send electrical signals.