Monday, December 5, 2011

The Nanomembrane Probe Brings Us Closer to a Cure for Epilepsy

This new device allows researchers to record brain activity over a much larger area and with higher resolution than anything previously used. Recording signals from the brain has just become a whole lot easier. And a lot more flexible. A new, ultra-thin device capable of recording brain activity without having to use penetrating electrodes could potentially allow researchers to learn information about the brain's electrical activity without invasive implants.

The device is comprised of 720 silicon nanomembrane transistors in an array consisting of 360 different channels. The silicon enables it to be more flexible and foldable than a conventional rigid electrode array. This means it can be placed not only on the brain surface, but inside the grooves or sulci and the deeper fissures as well as between the brain's hemispheres.

The array eliminates the requirement for each sensor to have its own separate wire. This arrangement allows the device to cover a much larger brain area with higher resolution than standard electrode arrays currently used by neuroscience laboratories around the world.

The team demonstrated the feasibility of the flexible electrode array by performing in vivo recordings on 10 cats using the new device. The investigators used the flexible array to observe responses to visual stimuli, electrical signals during sleep, and brain activity during induced epileptic seizures. In all three experiments, the researchers recorded types of signals that had previously only been recorded from brain slice preparations of brain, never from intact brain.

The signals observed during the seizures gave the researchers new insight into the pattern of activity that exists during epilepsy. The array recorded abnormal spiral waveforms that were very similar to the electrical signals produced by the heart during cardiac arrhythmias. The investigators, from the University of Pennsylvania School of Medicine and Bioengineering, believe that by preventing these abnormal spiral waves by breaking some of the neural connections that cause them, doctors could possibly cure epilepsy in humans.

This article was published online on Nov. 13, 2011, in the journal Nature Neuroscience.