Human epilepsy paper is published!
Our work on human epilepsy is finally published at Cell Reports!
The popular science blog post is coming, in the meantime I will explain in a few words what this work is all about.
Human epilepsy is a devastating disorder, it affects nearly 1% of human population. With the recent rise of humans on the planet, there are about 8 billion of us and 1%, i.e 80 000 000 people worldwide suffer from epilepsy. It is really devastating disorder, people could not drive a car, live a normal life and are usually living in the constant threat of having seizures at unpredictable times. Despite many years of developing drugs against epilepsy, about 30% of patients do not respond to any drugs, which gives little hope for these patients.
One way to create better drugs against epilepsy is to better understand the disorder first. There is a lot of research going on, but what exactly happens on the level of single cells in human brain during seizure is not well known. It is very hard to see what happens on the cellular level during seizure, because we could not record activity of single cells during this process. We know a lot about human brain at different levels, but it is often hard to put things together to understand the whole picture of disease mechanisms.
In our work we studied the tissue that has been resected from epilepsy patients suffering from seizures. These patients were undergoing the surgery to remove the area of the brain where seizures are being generated. For patients suffereing from epilepsy that is resistant to drugs brain surgery is often the only way get rid of seizures. This tissue allowed us a rare opportunity to study what happens with human neurons in the place where epileptic seizure get started. In our patients, seizures have started in hippocampus, the area of the brain that is normally responsible for new memory formation, but in case of epilepsy it goes wild and starts generating hyper synchronous activity that drives the whole brain crazy. Why is is happening with neurons specifically in hippocampus is not well known.
In our work we analyzed the data that comes from brain surgeries to answer simple question: why seizures start there? We recorded the activity and structure of single neurons derived from brain slices removed during the surgery. To be specific, we analzyed neurons called granule cells from the hippocampus. We found that cells in the epileptic brain become larger and receive more synaptic input from other neurons. This leads to the increase of excitability, i.e. neurons generate more spikes and become much more active than normal. Using computer models of single neurons and neural networks we found that even slight increase in neural activity and synaptic inputs in the hippocampus could lead to seizures that we studied using the computer model of human hippocampus. These results are also consistent with other findings showing that patients with more severe epilepsy tend to have more fast responding neurons, which we were able to explain using mathematical models we developed.
Of course, curing epilepsy is not be as easy as making perfect models of cells and networks of cells. But integration of the knowledge derived on different levels would help us to develop more efficient cures against epilepsy in the future. I hope our models and the data we generated would help to develop better treatments and therapies for people suffering from epilepsy. All models and data are available for other researchers for free: