Well, the paper we thought would be out by now is still undergoing analysis before we submit it. It turns out that the first round of computer calculations we did had a small error, and now we have to do them all over again! This probably won’t change the final results by much, but we have to be very accurate in what we present, so it is better to go back and do things right, even if it slows us down a bit. Because other scientists might look at our work and try to replicate our study, we have to do the best we can to make sure that everything is accurate. But I felt like kicking myself when I realized we would have to go back and do this all again! Science can be frustrating!

On another front, we are excited about the possibility of continuing our experiments with slices of brain taken from human epileptic patients. We may have another opportunity to record from a human slice in the coming month. These experiments are very interesting, because they allow us to get a glimpse of how human neural networks operate. Even though the tissue is taken from near a tumor, it still can tell us a lot about how human tissue differs from animal tissue. Are humans fundamentally different from animals, or do we just have more gray matter?

We are very careful to make sure that such tissue is obtained in the most ethical manner possible. The parents of the child who is undergoing epilepsy surgery are usually very eager to see research on this disease progress, so they are often wiling to sign consent forms allowing us to perform experiments on the tissue before it is disposed. We are very grateful for their courage and for their generosity toward our research, and it makes us want to find out as much as we can about epilepsy.

When we get such a piece of tissue, it is tempting to think about what it was doing in the patient’s brain. Was it a place where memories were stored? Did this chunk of brain hold a record of the first time this boy rode a bicycle, or was it a network that contributed to his sense of compassion for others? How will this person be different now that this small piece of tissue is removed? Like Hamlet contemplating Yorick’s skull, it is haunting to peer into a piece of matter and realize that somehow it “housed” a mind, a personality, or even what we call a soul.

Sometimes the whole is more than the sum of its parts. A human brain is about 3 pounds of water and fat, with a few salts thrown in between. But if you put all that in blender and mixed it up, it wouldn’t be very interesting. There is something about the particular arrangement of the fats into lipid membranes, and the salts into conducting ion solutions that helps to give the brain its interesting properties. When these materials are organized into cells, and these cells are connected into networks, and these networks transmit electrical activity, then amazing things begin to happen. I want to know how simple things come together to form more complex things. More specifically, I want to know some pretty ordinary ingredients can be organized to form a brain that processes information. While I probably won’t be able to get the final answers to these questions in my lifetime, I can certainly have fun trying to chip away at these issues.

Although a single brain cell is very interesting, it is probably not responsible for higher-level thought. We think that somehow groups of brain cells interact in interesting ways to process information. To see how groups of neurons interact, we put small chunks of brain tissue on an electrode array and eavesdrop on the electrical signals that the cells send to each other. Here is a picture of a slice of brain tissue on one of our arrays:

Caption: It almost looks like the Goodyear Blimp’s view of a baseball park. And to follow the ballpark analogy, listen to Science Diary: Frontiers of the Brain - The Wave to hear John Beggs speak about how “the Wave” helps explain how brain cells function. So what are we looking at? The circle in the center of the picture is a tiny dish that holds fluid to keep the brain tissue moist. There are 60 tiny electrodes in the center of this circular dish that you can’s see at this magnification, but they are located where there seems to be an “X” in the middle. The brain slice is the grayish, pear-shaped piece that is placed on top of the X. The tubes you see coming from the upper left side of the picture are for carrying in fresh fluid, and carrying away old fluid. The gold colored posts you see attached to the charcoal colored box are electrical contacts which take the signals from the brain slice and carry them to an amplifier, and then to a computer. After they are stored to a computer disk, my students and I spend weeks and months analyzing them. We want to know what these brain cells are saying to each other…