Is the human brain the most complex thing in the universe?

In this brief guide we are going to answer the question ‘’Is the human brain the most complex thing in the universe?’’ We will mention how the brain is divided and what its main functions are. In addition, we will highlight the main goals of neuroscience.

Is the human brain the most complex thing in the universe?

Yes, the human brain is the most complex thing we have discovered in the universe. It contains hundreds of trillions of cells that are connected through trillions of connections.

If we ask what is the most complex structure in the universe, the answer is categorical: the brain (let’s be anthropocentric and let’s say human). Why?

Astronomist Carl Sagan said: “The total number of stars in the universe is greater than all the grains of sand on all the beaches on planet earth.” We are talking about ten sextillion stars, a 1 followed by 22 zeros (1×10²²). In size, the universe studied ranges, according to estimates, between 13 and 48 million light years.

In comparison, the human brain has approximately 1×10¹¹ neurons that interconnect with each other 1×10¹⁵ times (in a changing manner). All this with a weight of around 1.5 kg and a volume of 1,300 cubic centimeters. That is enough to tell us who we are: beliefs, political preferences, sports predilections and who we fall in love with.

In parallel to its most important function, guaranteeing the survival of the body that houses it, its exponential development has led it to the paradox of being an organ that tries to understand itself. This is what we do, among others, neuroscientists, who try to answer the question that poses perhaps the greatest scientific challenge in history: how does the brain work?

How does the brain work?

Knowledge about how the brain works is enormous, but it’s still too fragmented. This has the consequence that, although it seems incredible, we know less about the brain than about the planet Mars.

However, it is known where and how some basic and fundamental processes of brain activity occur. This is particularly the case with the cortex (or cortex), which is understood as the “most human structure” of the organ of life.

Be that as it may, since the Nobel Prize winner Ramón y Cajal revealed more than 100 years ago the possibility of appreciating the landscapes of the brain, neuroscientists from around the world have not stopped advancing and studying the wonderful reality thanks to which we live. Let’s start.

Although we rarely stop to think about the importance it has within the regulation of our daily activities. Anatomically, the brain is the largest part of the brain and is divided by a central sulcus called the longitudinal fissure in the right and left hemispheres, both joined by the corpus callosum.

The surface of each hemisphere presents a set of folds that form a series of irregular depressions, these are grooves or fissures. The arrangement of these grooves is never the same between the brains of different people. They also adopt different dispositions on both sides of the same brain.

The Brain

Each cerebral hemisphere is divided into four lobes: the frontal, the parietal, the temporal, and the occipital. In general, the first four lobes are located below the bones of the same name.

Thus, the frontal lobe rests deep in the frontal bone, the parietal lobe under the parietal bone, the temporal lobe under the temporal bone, and the occipital lobe under the region corresponding to the occipital protuberance.

The brain contains trillions of cells, of which about 100 billion neurons, and has nearly 100 trillion interconnections in series and parallel that provide the physical basis for brain function. Thanks to the circuits formed by nerve cells or neurons, it is capable of processing sensory information from the outside world and from the body itself.

The brain performs less well defined sensory functions, motor functions, and integrative functions associated with various mental activities. Some processes that are controlled by the brain are memory, language, writing, and emotional response.

Neuron

The functioning of the brain is based on the concept that the neuron is an independent anatomical and functional unit.

The neuron is made up of a cell body from which numerous branches called dendrites emerge, capable of receiving information from other nerve cells. It also has a main extension, the axon, which conducts information to other neurons in the form of an electric current.

Neurons do not connect to each other by a continuous network formed by their processes, but rather by contacts separated by narrow spaces called synaptic spaces. The transmission of signals through synapses is carried out by chemicals known as neurotransmitters, of which more than twenty different classes are known today

Brain lobes

Today it’s known that visual information is received and analyzed in the occipital lobe. Certain visual and auditory sensations are governed in the temporal lobes. The voluntary movements of the muscles are governed by neurons located in the most posterior part of the frontal lobes, in the so-called motor cortex.

The frontal lobes are also related to language, intelligence and personality, although specific functions in this area are unknown. The parietal lobes are associated with the senses of touch and balance. At the base of the brain is the brain stem, which governs respiration, coughing, and heartbeat.

Behind the trunk is located the cerebellum, which coordinates body movement while maintaining posture and balance. The areas of the brain that govern functions such as memory, thinking, emotions, consciousness, and personality, are much more difficult to locate.

Limbic system, hippocampus, hypothalamus and cortex

Memory is linked to the limbic system, located in the center of the brain. When it comes to emotions, the hippocampus is known to control thirst, hunger, aggression, and emotions in general.

It’s postulated that the impulses from the frontal lobes are integrated into the limbic system, reaching the hypothalamus, a structure that in turn regulates the functioning of the pituitary gland, which produces several hormones.

It’s in the cortex where cognitive capacities are integrated where our ability to be aware, to establish relationships and to make complex reasoning is found. What we call gray matter is a small layer that covers the rest of the brain.

But the human cerebral cortex has one feature that sets it apart from all the others: it has numerous folds. This notably increases its surface area. If we extended it, it would occupy the area equivalent to four pages. By comparison, a chimpanzee’s would only be one page, a monkey’s would fit like a postcard, and a rat’s would be a postage stamp.

The processing of sensory information collected from the world around us and from our own body, motor and emotional responses, learning, consciousness, imagination and memory are functions that are carried out by circuits formed by interrelated neurons through the synaptic contacts.

It’s for this reason that brain function resembles, in part, a computer. But the brain is much more complex than a computer, since it is endowed with properties that only its biological nature provides.

The brain: a stranger in our head

It’s the most complex and least known organ. How do memories accumulate? Where are the ideas? Will it be possible to stop diseases like Parkinson’s or Alzheimer’s?

There are many challenges that the brain, with its 100,000 million neurons, poses to medicine and science. In fact, the number of unanswered questions still surrounding him may be around that same number of brain cells.

The ambitious “Brain” initiative – launched in 2012 by the Barack Obama administration – is just the latest attempt to draw a dynamic and comprehensive map of what its name makes clear. 

The task is not easy, not at all, so it will count on the joint work of the Pentagon, the National Institutes of Health, the Research Agency for Advanced Defense Projects and the National Science Foundation, Google, Microsoft and others.

In turn, the Human Brain Project is the European equivalent, in which all the existing knowledge about the brain is already being compiled in order to translate it into a supercomputer that, finally, would generate the most virtual simulation that has been done in the field of neuroscience.

This interdisciplinary project has the efforts of 80 partners, including professionals from medicine, pharmacy, computer science, microbiology and biotechnology, among others.

Collect and understand: those are the main tasks of anyone looking to get closer to the eternal unknown that humans carry in our heads.

Many specialists believe that it’s impossible to reach the final understanding of the brain, but it must be approached. Our great challenge is to know that there is no end, but to try to find it.

It’s ridiculous to pretend to simulate the brain as if it were something static, since it’s a variable organ over time and in each individual.

What is the north?

On the one hand, research in this area is aimed at objectively diagnosing and treating neurological disorders, neurodegenerative diseases and brain diseases in general.

Clinical research seeks treatments for Parkinson’s disease, Alzheimer’s disease, epilepsies, brain tumors, and cerebrovascular diseases. The aim is to identify the risk factors that allow prevention and not only cure.

In the clinical field, it’s intended to explore in greater depth everything related to neurotransmitters.

Whether serotonin, acetylcholine, endorphin, dopamine, norepinephrine, or other neurotransmitters, these are biomolecules that carry information from one neuron to another through the “synaptic space” that separates two brain cells. They are grouped according to the particular characteristics of each one and must not only be produced, but also degrade.

Some theorists argue that what is known so far about the brain is only 20%.

When these substances are lacking or in excess, imbalance problems are generated that can lead to ills such as those already mentioned. Even falling in love can be a neurotransmitter problem!

Another branch where there is much pending research aims to understand the “brain structure-function” duo, that is, how the different parts fit and work together.

There’s a dichotomy between the mind and the brain, and therefore, one of the challenges is trying to understand how ideas have a physical substrate and, every time one learns something, the nervous morphology is altered. Where do the ideas come from if all neurons work with sodium and potassium? 

The unanswered questions continue to grow: for example, some researchers argue that memories are stored in the form of proteins, while others claim that they are stored with modifications of the DNA of cells.

There are also thoughtful debates – still inconclusive – about how memories are subdivided. We talk about short-term memory (which is acquired, but is soon forgotten), medium-term memory (lasts for days) and long-term memory (lasts for years). To this list, working memory was recently added, which is short-term but requires processing.

In neuroscience, as in other medical fields, every research process takes years of study, testing, and verification. That’s why no immediate findings can be expected even in multi-million dollar initiatives like Brain or the Human Brain Project. The first firm discoveries of both initiatives may see the light of day in decades.

However, there is hope for neuroscience because, little by little, the picture is clearing up. For example, achievements such as those of radiosurgery, which, through gamma rays, access small lesions in inoperable areas of the brain from the outside, without causing damage to adjacent tissues.

Or the advances in neuronavigation (triangulation technique to find intracranial lesions or tumors more precisely), neuroendoscopy (treatment of brain pathologies through small holes in the skull), and epilepsy surgery…

There are other techniques under development – for now, in an experimental stage with mice – such as clarity, which bleaches the brain with dyes that allow us to see where brain connections are failing, or brainbow, which colors neurons with different fluorescent proteins.

It seems impossible to explore the details that explain the billion trillion connections that occur in our heads, but the challenge is exciting for science.

In the words of Story Landis, director of the United States National Institute of Neurological Disorders and Heart attacks:

“Exploring how the brain works is the last great frontier.”

Understanding an organ that has 80,000 million neurons, each of which makes, on average, more than a thousand connections between them, is an immense and long task. But the progress that has been made in the last 25 years has been spectacular. 

FAQS: Is the human brain the most complex thing in the universe?

References

Ackerman, S. (2020). Foreword. Retrieved October 23, 2020, from Nih.gov website: https://www.ncbi.nlm.nih.gov/books/NBK234155/#:~:text=The%20brain%20is%20the%20last,interlinked%20through%20trillions%20of%20connections.

Frackowiak, R. S. (2004). Human brain function. Elsevier.

Raichle, M. E. (2010). Two views of brain function. Trends in cognitive sciences, 14(4), 180-190.