What is neuroplasticity and why are scientists still unable to understand how the brain works?

The human brain is the true crown of evolution.This organ, weighing several kilograms, creates your personality every second. Billions of tiny neurons spark electricity, and our psyche is nothing more than a product of the brain. Needless to say, it is the brain that is the most unexplored organ of the human body and regularly leaves scientists at a loss. In fact, the brain is a powerful engine, thanks to which we stay afloat even in the most extreme situations. We are able to adapt to the harshest conditions - our brains are neuroplastic. Scientists define neuroplasticity (or brain plasticity) as the ability of the nervous system to change its activity in response to internal or external stimuli by reorganizing its structure. Research in the last century has shown that neural plasticity is a fundamental property of the nervous system in all species, from insects to humans. However, despite intensive research into the mechanisms governing plasticity, it is still not clear how exactly plasticity shapes the morphology and physiology of the brain. And the results of a recent study left scientists completely discouraged and unable to understand how the brain works.

The study of the brain often leaves scientists at a loss.

What is neuroplasticity?

Our brains are known for their flexibility or"Plasticity" because neurons can create new or stronger connections with each other. But if some connections become stronger, neurons must compensate for this so as not to be overloaded with input data. In a 2019 paper, researchers showed for the first time how this balance is achieved: when one connection, called a synapse, is strengthened, neighboring synapses are immediately weakened by the action of a critical protein called Arc.

In the course of work, the team discovered a simplea fundamental rule behind a complex system like the brain, where 100 billion neurons each have thousands of constantly changing synapses. This discovery, according to its authors, provides an explanation for how synaptic amplification and attenuation combine in neurons to create plasticity.

Our ability to reprogram individualneurons in an intact brain and to observe in living tissue a variety of molecular mechanisms that allow these cells to integrate new functions through synaptic plasticity is striking, the authors of the study write.

By the way, the hippocampus, for example, helps animals navigate their surroundings.

Seeing the new rule in action, researchersstill struggled to understand how neurons obey him. The work carried out at Sur Labs combines advanced imaging techniques and genetic tools to perfectly monitor the function of individual synapses within the brain. Thus, the information obtained by the researchers makes it possible to understand how neural connections develop and are reconstructed.

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Neuroscientists in confusion

So, if we want to finally understand how it worksthe brain, then, must focus their efforts on the study of synaptic plasticity. Interestingly, until the nineteenth century, the brain was primarily considered by philosophers, and therefore it was not until the late 1800s and early 1900s that the foundations of modern neuroscience were laid. In the last decade of this century, several scientists have made key contributions to our current understanding of synaptic plasticity.

But, alas, there are no fewer questions.The point is that the brain has to be flexible, but not too flexible. It is constantly being rebuilt through new experiences, but how? A relatively simple explanation can be obtained, for example, from neurologists. For example, an article for The Atlantic says that certain groups of neurons are reliably fired when their owner smells a rose, sees a sunset, or hears a bell.

Scientists are facing a very difficult task, whatever one may say

These patterns of neural response patterns are assumed to remain the same from one moment to the next. But as the authors of the new study and others have found, sometimes this is not the case.

In the course of the work, a team of researchersColumbia University allowed mice to sniff the same odors for several days and weeks and recorded the activity of neurons in the rodents' piriform cortex, an area of ​​the brain involved in smell recognition. At a certain point, each smell triggered a specific group of neurons in this area.

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Mysterious neurons

Over time, however, something strange began to happen - some neurons stopped responding on smells, while others started.The neurons that represented the smell of an apple in May and those that presented the same smell in June were just as different from each other as those that represent the smells of apples and grass at any given time.

It should be noted that this is a new and only study in this area. However, other scientists have previously shown that the same phenomenon, called representative drift, occurs in various areas of the brain besides the piriform cortex. Its existence is clear; everything else is a mystery.

Here's what the study authors themselves saidto reporters: Scientists need to know what's going on, but in this particular case we are deeply confused. We expect it will take many years to sort this out.

The brain can change throughout our lives

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If neurons in the piriform cortex react to a certain smell, then the likelihood that it will react to it in a month, is only one in 15! At any given time in response to every smellthe same number of neurons fires, but their identity changes. But how does the brain know what the nose is feeling or what the eyes are seeing when neural responses to smell and vision are constantly changing?

Ultimately the drift that is talked aboutspecialists, it may just be a mistake of the nervous system - a problem that needs to be addressed. “Connections in many parts of the brain are constantly being formed and destroyed, and each neuron itself constantly processes cellular material,” the scientists explain. And yet, some call their work flawed - mainstream neuroscience relies on very specific methods and results and transforms them into a cloud of vague concepts.

Where would modern science be without these rodents?

In many areas of neuroscience, the premises remain unexplored, but everything else is flawless, the scientists explain. There is a real demand for new ideas in this area, the researchers say.

And for good reason, for we need new theories andideas. Neuroscience is so immature and conceptual today that scientists are, in fact, at the stage of gathering information and facts. However, I think that in the coming decades we will finally be able to say: “we understand how the brain works, glory to science”.

Ultimately, the latest research inareas of brain development as we get older, inspire optimism and make our lives better. But about how the brain of adolescents differs from the brain of an adult, I talked about in this article, I recommend reading!