2023-05-16 13:52:58
In both neuroscience and astronomy, more and more answers to complex issues are emerging, but there are still many ‘loose ends’. Read here how things are in astronomy.
It depends a bit on where you’re looking: according to many websites and textbooks, our brains have about 100 billion neurons – nerve cells that are the building blocks of our brain. Elsewhere you will find the more precise number of 86 billion, following one of the few attempts to actually count them in a 2009 study. It says everything about the complexity of our brain.
Anyway, there are many, many.
If we really want to fully understand the brain, we have to understand all those billions of nerve cells. But even then, even if you know how each neuron works, you don’t know how they work together. And if you know how they work together, you don’t know exactly what they do together. And even if you know that, how do all those joint projects shape our character, our consciousness?
Jennifer Aniston
When you look at a famous actress and recognize them, the neurons that store that memory fire in your brain.
It seems like an almost impossible task. “On a molecular level, we are relatively advanced,” says neurobiologist Cyriel Pennartz of the University of Amsterdam. “How the proteins that make them work, how they ‘fire’ electrical signals, how they communicate with other neurons through ‘synapses’. That’s all actually very straight forward. We also quite understand the level above that: how small networks of nerve cells transfer signals to other networks.”
After that it gets tricky. Groups of these small networks together organize our memory, language, thoughts, actions and emotions. The translation of all kinds of smells, images and sounds into complete concepts with feelings, memories and meaning is a big open question. “For example, if someone looks at Jennifer Aniston, scientists can see that certain cells start firing when the person recognizes the actress. And deduce how groups of neurons transfer that information to other groups. But how do those cells ensure that our brain interprets such a concept, that we understand that we are looking at Jennifer Aniston and what this does to us?”
Looking into the brain
That’s what we really want to know in the end. Identifying those 86 billion puzzle pieces doesn’t say much. It only becomes interesting when large parts of that puzzle have been put together. And how nice would it be if we could see the whole puzzle in its entirety?
Then you end up with understanding our consciousness. According to neurophysicist David Norris of the Donders Institute, that is in fact the highest goal. “As humanity, we want to know who we are, what makes us unique.” It is precisely the larger questions that are popular with the general public. “People are tapping into themes such as mind reading, controlling dreams and improving memory. We are slowly learning little bits about this, but we are not yet close to the big picture. We slowly get to know the orchestra, but not the conductor.”
Technological developments, such as the use of MRI scans, are making more and more possible for brain researchers.
Roeland Segeren, via Envato
Roeland Segeren, via Envato
What we now see as small steps are giant steps compared to the past. Less than half a century ago, brain researchers mainly conducted their research by cutting the brains of deceased people and animals. Until the advent of techniques such as EEG, MEG and MRI. “We now have a whole army of non-invasive ways (without entering the body, ed.) to examine the brain, which allows us to look into the brains of living people. This has already yielded insights into the way our brain deals with numbers and what happens when we read or write. And those techniques have improved greatly in recent years.”
Brain scans show which parts of the brain come into action when, for example, a test subject looks at certain images, hears sounds or reads texts. Thanks to technological progress, we can do this more and more precisely. In the coming years, the heaviest MRI scanner in the world will be built in Nijmegen, under the leadership of Norris. “It will have a magnet strength of 14 Tesla (the unit for magnetic force, ed.), allowing us to look into the brain with a precision of 0.3 millimetres. This makes it possible to study small groups of neurons in living people.”
Turn cells on and off
According to neuroscientist Alexander Heimel of the Netherlands Institute for Neuroscience, the biggest breakthrough in brain sciences lies in that kind of technological progress. We may not immediately see how our consciousness works, but we can now see more closely what is happening. And in such a way confirm or disprove what we have thought for some time.
For example, scientists can now ‘turn on’ cells to see what they are doing. “We first did this with electrical pulses, now with light. This allows us to really turn memories on or off in rats and mice. We’ve suspected how this works for about forty years. We can confirm such theories with new techniques. Comparable to black holes in the universe: there was no great doubt, but nice if it is confirmed.”
Our brains have 86 billion neurons, each with hundreds to thousands of connections.
Roeland Segeren, via Envato
This technology will continue to develop for the time being. That will certainly help brain science advance, but it also creates a lot of new challenges. Heimel: “We are gaining more and more knowledge. How are we going to integrate and simplify that with each other? Because all the separate data doesn’t say much about the whole. We understand the basic principles of memory, for example: when a certain memory is triggered, the same neurons fire each time. But why exactly that one? And how exactly is that memory recorded by those cells?”
Resolving problems
Brain science is certainly no longer in its infancy, but it has not progressed much further than puberty. The way in which we tackle mental illness in 2023 is exemplary. “We can use electrodes to make a tremor (a contraction of muscle groups, ed.) disappear in Parkinson’s patients. There are medications for schizophrenia, depression, and ADHD. But these types of treatments are generally discovered by just trying. The solution is often not thought out in advance based on how the brain works.”
Nevertheless, according to Heimel, we are on track for both medical applications and the general understanding of our brain. “That is interrelated. These techniques will be refined because we know better what is happening in which area. If we understand the brain, we can search more specifically for solutions to problems such as depression and schizophrenia. With genetic technology, for example, we could one day replace damaged or dying brain cells. We are still a long way from a complete understanding of the brain, but we are slowly starting to fill it in.”
Brain remodeling
Will we ever understand our brains for the full one hundred percent? That would mean that our knowledge of ourselves and everyone else would be complete. According to the brain researchers, there is a limit precisely to those individual differences. “We are nowhere near our technological limits,” says Norris. “Understanding each individual’s brain, with all its differences, is always difficult, I think. But one day we will arrive at a fairly complete knowledge of a general, average brain.”
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Pennartz agrees, with the caveat that a different way of research is needed. After all, just like in astronomy, brain research can be divided into all kinds of disciplines, from psychology to biology to genetics. “Everyone has their own specialist knowledge. Moreover, all those researchers work within their own grants and for their own bosses.” A large umbrella project to understand or reconstruct the brain, such as the Human Brain Project, therefore requires far-reaching agreements to share knowledge and work together.
The greatest challenges to ever fully understand our brain may therefore lie in education and organization. “It would be nice if students and researchers were better trained in thinking bigger. Now they are often very deep in one subject. But I think we can eventually understand and even recreate the brain. There is now a common perception that our brains are too complex to ever understand in part. For those who share that opinion: speak for yourself.”
Also read about unsolved questions in astronomy
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