Our brains are just about the most complex electrical circuits imaginable. For starters, each of us has about 86 billion different electrically active brain cells. Amongst these 86 billion, we have all different kinds of cells, with different ones doing different things in the brain.

And then we have to consider that these cells aren’t lone rangers. They work together, sending tiny electrical signals to their neighbours, to give rise to our brain function. It’s hard to say exactly, but there could be something like an estimated one thousand trillion (that’s 1,000,000,000,000,000!) electrical connections between cells in our brains.

In epilepsy, we know that seizures can happen when our brain cells don’t get things quite right, and send too many electrical signals or ones that are too big. So, as researchers, we need a way to be able to measure exactly what brain cells are doing during seizures. If we can see what’s gone wrong, we can then get to work on trying to fix it.

That’s where a handy research technique called electrophysiology comes in.

Using tiny recording electrodes, combined with very sensitive measuring devices, we can directly measure electrical signals in the brain.

Electrophysiology is used in different ways and on different scales. For example, we can grow brain cells in a dish, and measure the electrical signals from just one of them. Some of these cells are 100 times smaller than a millimetre! We can also measure two cells at the same time, and understand the signals that they are using to ‘talk’ to each other.

On a bigger scale, we can measure the overall signals created by a big group of brain cells. But, this has the drawback that we can’t see what exactly what each individual cell in the group is doing.

In a research setting, we often use a combination of different electrophysiology techniques, depending on the type of question that we want to answer.

The power to measure electrical signals in the brain makes electrophysiology a key tool in epilepsy research. Not only can we use it to visualise how our brain cells are behaving (or misbehaving!) during a seizure, but we can also use it to test new drugs and treatments which might help people with epilepsy.