Q&A with neuroscientist Veronika Zlatkina
How much do we know about the brain?
We know very, very little about the brain, but much more then we knew say 200 years ago. I think what we know most about is probably anatomy, because anatomy is something that is seen with the eye. We can study the surface and folds of the brain; if we cut a brain, we can study it under the microscope and see its structures. As for the functions, we don’t know much about that.
What tools are there for studying the brain?
One of them is magnetic resonance imaging, which allows us to understand which parts of the brain are involved in the performance of different tasks—for example, which parts of the brain are involved when we see a red square or listen to an analogy.
And, what we know is that we can look at the brain or a portion of it (roughly a 1 cm by 1 cm area) and we can tell what this region is doing but we can’t see individual cells and we cannot say what individual cells are doing.
Is it because there are too many neurons in the brain that we can’t understand what they are all doing?
There are many neurons and they are very small so at this level—if we speak of the human brain—we can only record the activity of patches of neurons but not of a single neuron.
However, the information processing occurs at the level of the single cell. So, we know what the ensemble of cells is doing but not what the single cell is doing. To complicate things further, even if we were able to see the activity of a single cell, we would not know what to correlate it with:
For example, if a person is reading a text and see a cell fire, what exactly is the cell responding to? Is the cell responding to a picture, a letter or a thought? This is difficult to answer because most tasks (at least those that are remotely interesting) are very complex.
Which animals do scientists most typically use in the lab?
Scientists work a lot with, and study, rats and mice. When people study the activity of individual cells, they work with molluscs (such as snails). But we also study other types of animals such as frogs, which go together with molluscs in terms of individual neuronal activity. Sometimes, scientists also study cats and dogs. Which animal you choose to study depends on what you want to study. If you want to study the brain itself, you study mice, rats and monkeys. But if you study the physiology of the body, then you can work with dogs, pigs and other mammals larger than mice.
We hear a lot that only a certain percentage of our brain is used and the rest is not. So, what does it mean exactly?
People say we use 10% of our brain, but there is nothing that really suggests this is true. You can use an MRI scanner, which allows you to see which parts of the brain are active by showing you how much oxygen is supplied to that part of the brain. So if you place a patient there while they are sleeping or relaxing, and you look at the picture of the brain, every single part of the brain is doing something.
When we want to know which part of the brain is working more or harder, we always have to compare our results to the base line, which is when the subject is doing nothing.
Then you ask the person to perform a task such as reading a text, and you can identify the language area of the brain. However, all the brain is working at the moment because we know of very few areas in the brain where a damage to that area has no impact on the patient.
How far away is research for brain regeneration?
People are working on it, I believe it can be done soon. When people work on brain regeneration, they don’t just work with humans. What they do is get samples of neurons from rats or mice and put them in a petri dish and give them nutrients to let them grow and divide.
After that, they break them at certain points and try to use chemicals or other techniques borrowed from biomedical engineering to fix the broken points. They can see the results in the dish. But how to go from the dish to the actual specimen is something hard to do. I believe we will get there but it’ll take time.
Other than neurons, are there other kinds of cells in the brain?
Yes, neurons also have support cellsthat we call glia, of which we know 3types. So the brain functions because our neurons are able to conduct theimpulses, send and transform information.
But the glial cells keep the neurons alive and functioning. They are the cells that help the nutrients get to the neurons from the blood vessels. And to keep neurons together, we need glia, which translates to “glue” from Greek. In other words, glial cells are involved in maintenance, or house keeping, functions.
What kind of research do you do?
That’s my favourite question. I study the anatomy of the parietal lobe, which is one part of the brain. More specifically, I study the sulci, which are the folds on the brain surface.
People sometimes think they are just randomly arranged, while others think they aren’t random but are just very hard to study. What we know so far in terms of their anatomy dates back to the beginning of the 20th century.
What I do is try to go a bit further using MRI scans of many patients. I’ll study their sulci and try to subdivide the regions in terms of the patterns or irregularities that are formed in the human brain.
The reason for studying that is that we believe the sulci to be like landmarks. If you think of the human brain like the Earth, next to rivers, we usually have towns. In the case of the brain, next to the sulci (the rivers), we have different functional areas.
The question I‘m trying to answer is: If I subdivide the sulci into basic units, will I also be able to find basic functional units very close? One application of this research is for surgeons who are doing surgery and have a digital image of the brain. This would help them to find out how much of a tumor they can remove safely without affecting the patient’s capabilities
