Electrode loaded with drugs monitors brain, treats convulsions

Neuroscientists have designed a new polymer-coated electrode that can detect unusual brain activity and then deliver drugs straight to the brain cells.

One day, an epileptic seizure could be detected at the onset, and immediate treatment would be possible.

When implanted into the brain, microelectrode arrays – which have multiple neural interfaces – allow researchers to observe the electrical activity of our neurons.

Sometimes they can even manipulate the electrical activity... so why not chemically influence the brain while they’re at it?

So Xinyan Tracy Cui at the University of Pittsburgh and her colleagues did just that.

1. They coated microelectrodes with an electrically conductive film made of polypyrrole – a polymer that, well, conducts electricity.
2. Then they loaded up the pockets in the film with different drugs and neurotransmitters like dopamine.
3. They attached the array to rat brain tissue and applied an electrical current to the polymer.
4. With the voltages, the shape of the coating became warped and it released its pharmaceutical cargo, which then acted on the surrounding brain cells.

Polypyrrole-coated microelectrode arrays, like ordinary arrays, can monitor neurons for unusual electrical activity and also deliver electrical impulses to keep neurons firing at the right tempo. They’re like brain pacemakers for treating epilepsy.

However, with the new coating, the electrodes could release drugs when they detect unusual activity, such as the chaotic electrical firing of seizures. And since the electrodes reach into specific parts of the brain, only nearby neurons would be affected by the drugs.

"Theoretically you could use the electrode arrays to monitor neural activity and once you detect a sign of a seizure you could pump anticonvulsive drugs at just the right location," Cui says.

But right now, the polymer can only administer a limited amount of drugs to the brain. In order to avoid future procedures for resupplying the coating with drugs, the team would need to connect it to some drug reservoir; maybe carbon nanotubes.

Trials have begun with live animals to see if the new technology could help people with epilepsy control their unprovoked seizures.

The study was published in Journal of Neural Engineering earlier this month.

Via New Scientist.

Image of the brain from Gray's Anatomy via Wikimedia

This post was originally published on Smartplanet.com