The human brain has long puzzled scientists, as this part of the body that lies inside a fortified skull has enormous capabilities that enable it to perform extraordinary calculations, and to create and understand in ways never seen before in the known universe, all using enough energy to glow a 20-watt light bulb.

Man has been able to achieve major breakthroughs in the understanding of the human brain. In recent years, we've discovered that brain cells can be regenerated and we've identified what's happening in the brain when you start talking before we know what to say. However, the more we learn, the more we realize that there is much we don't know. In these lines, we will try to explore together the biggest puzzling questions about the brain to uncover the mechanisms and secrets of this wonder mass of precision manufacture.

What makes our brains special?

The human brain, as we like to claim, has enormous powers. Other animals can use tools or emerge from labyrinths, but can they invent computers or write poems like humans do? But despite our extraordinary mental prowess, it's not easy to explain what makes the human brain so special. The human brain weighs about 1.5 kg, which is about a third of the weight of an elephant's brain and a fifth of the sperm whale's brain.

However, if we take body size into account, our brains are unusually large, with the human brain between seven and eight times larger than what would be expected for mammals of the same size. But this primitive analogy is not enough to explain our intelligence. For example, the ratio of the brain-to-body size of a capuchin monkey is higher than that of a gorilla, yet gorillas are smarter.

Obviously, size isn't everything, but perhaps the most important metric is the number of neurons, which are the processing units in the brain. Brazilian neurologist Susanna Herculano-Husel of Vanderbilt University in Tennessee, who has developed new ways to calculate the number of neurons, said humans have about 86 billion neurons.

In fact, primate brains have more neurons than other mammals of similar size. Since humans have the largest brain size among all primates, they also have the largest number of neurons, and possibly among all other animals. This was likely achieved through the invention of cooking, which releases more calories from food to feed this energy-consuming organ in the human body.

However, it may not only be the number of neurons that matter, but also where they are located. Herculano-Husel points out that our remarkable abilities likely stem from the presence of a large number of neurons in the cerebral cortex — the surface layer of the brain made up of grooves and convolutions that help dramatically increase the area of the cortex — than other animals. This structural structure allows us to develop more complex behaviors rather than just responding to stimuli. So Herculanu-Huzel says, "If you have a cerebral cortex, you're no longer a slave to what's happening around you. You have the flexibility to choose to do other things."

Furthermore, her team recently discovered that across all warm-blooded animals, the number of neurons in the cerebral cortex is associated with longevity. Herculanu-Husel believes that this is also a major factor in our cognitive superiority, as it takes humans years to mature. She explains that "it takes a very long time for a person to build a brain, and during that time, he acquires and assimilates information from the world around him." This may not be attributed only to neurons alone, there is also another type of cell called astrocytes that play an important role in the development of human intelligence. But the enormous computing power offered by the 16 billion neurons in the cerebral cortex is likely the factor that contributes critically to our cognitive dominance.

What awareness?

The conscious mind can be visualized as a hearth. So when a person is deeply asleep, the flame of consciousness recedes to a low but steady level. In REM sleep, given that dreams occur precisely at this stage, the flame escalates and ignites brightly but irregularly. In a coma, the flame looks like a glowing flame.

In other words, awareness exists in a number of situations. One explanation for this is that full consciousness appears when many parts of the brain transmit information to a network of neurons known as the "overall working area." When this broadcast does not occur, the sensation remains in an unconscious state. If this broadcast is not complete, you feel different levels of awareness, such as when you dream or receive a blow to the head.

By studying these cases, we should one day be able to determine the mechanisms of brain functioning from which consciousness arises. Why, then, are attempts to explain consciousness described as a "difficult dilemma"?, how can a group of neurons weighing up to 1 kg or so evoke a series of thoughts and feelings that make up our mental experience? One of these reasons is the focus of philosophers on explaining how experiences are perceived. The term "perceptible qualities" coined by philosophers describes the properties of the experiences to which we are subjected, the state in which the qualities of things are viewed from a subjective perspective in a state of consciousness, such as the red color of strawberries or the feeling of the taste of wine. But trying to come up with explanations for perceived modalities causes endless confusion among neuroscientists.

One solution to this dilemma is to simply ignore it. Patricia Churchland, a philosophy professor at the University of California, San Diego, says that "'perceptible qualities' is an artistic term introduced by philosophers who want to make questions about the nature of consciousness subject only to vague explanations that are not based on biological evidence." After all, we're not usually talking about our perceived qualities, we're talking about things like feeling tired, needing to eat or even falling in love, all of which have a direct biological origin and are not mysterious.

The brain only brings to our consciousness the things that occupy a large part of our attention, and it does so in a way that we can understand

Philosopher Daniel Dennett of Tavats University, Massachusetts, explained that most people may not realize their perceived qualities until philosophers push them to think about it. What's more, Dennett not only believes that there is no difficult dilemma, but that consciousness itself is a kind of illusion. He explained, "It takes some objective persuasion and flattery to make people 'notice' their perceived qualities, and when they believe they have already noticed it, they fall into another illusion."

That delusion, according to Dennett, is that each of us thinks we have a special privilege to access some of the wonderful characteristics of our mental states, which we think we are intimately familiar with and consider as learned experiences. But the brain only delivers to our consciousness the things that occupy a lot of our attention, and it does so in a way that we can understand. For example, this is why we see things in certain colors. While the real world may not look that way, our visual system effectively assigns a color code to the world around us, in order to simplify it.

Illusions of the mind

Dennett claims that as much as color can be considered a mere illusion created by the brain to adapt to the world, so too can consciousness. He explained that "consciousness is a means of 'user illusion' that arose as a result of evolution to facilitate the life of the brain that must lead the body through a risky life."

Smartphone designers call the phone screen the term "illusion or user deception." The screen is the computer interface underneath, but the icons that appear on it, such as the envelope icon symbolizing the Messages app, are symbolic clues, unrelated to the actual hardware and software responsible for the functioning of the phone's messaging system. If we think that our brains are like smartphones, consciousness is the screen, which acts as the interface for our brains. But that metaphor is not accurate, says Churchland. For example, when we feel dizzy or determine where a sound comes from, it is caused by physical processes occurring in the brain. Perhaps awareness is like a smartphone screen that displays different apps according to how much power is left in the battery or how much the phone vibrates. In other words, consciousness is a partial illusion, representing an image that the brain brings its parts together as a result of all the input it receives and the complete transmission of information from parts of the brain to the network of neurons.

Are smart people's brains different?

The short answer to this question is yes. People vary in their intelligence, so how can we explain this difference if we don't attribute it to differences in brain structure or function? However, these particular differences are the subject of in-depth research. The first thing to notice is that people with big brains often already have a higher IQ, but there are more factors that control this than just size. To learn more about this, we need to look closely at the white matter and gray matter that make up our brain. Gray matter is made up of the main bodies of neurons, while white matter is mainly made up of axons that transmit electrical signals. Roger Kievit and colleagues from the Medical Research Council's Cognition and Brain Sciences Unit in Cambridge, UK, discovered that gray matter volume in the frontal lobe is linked to fluid intelligence, which is the ability to think logically and solve new problems without prior knowledge, by recognizing patterns and relationships and using deduction to solve problems. They also found that this was related to the amount of white matter bonds found between the frontal halves of the brain.

However, it doesn't just depend on the amount of tissue. One of the most surprising features of mammalian brains is the presence of deep grooves and convolutions of gray matter on their surface, giving them a walnut-like appearance. In addition, they help to significantly increase their surface area, bringing cells closer together and allowing them to communicate faster. To be sure, the amount of these grooves is related to the speed of thinking and working memory, as smarter people have more convolutions of brains.

However, we still don't know where intelligence resides in the brain. To explore this, we can rely on one of the most famous ideas about the location of intelligence, a theory known as the "frontal temporal integration theory." This theory suggests that the biological basis of intelligence is a network that connects different active brain regions. We can find evidence of these active areas in studies based on brain imaging. Ulrike Basten and colleagues at Goethe University in Frankfurt, Germany, have identified a network of 20 different frontal and temporal regions associated with intelligence by studying how parts of the brain are activated while performing cognitive tasks. They found that gray matter density or the strength of neural activity in these areas indicates a high IQ.

It seems that we are close to a conclusion, but this evidence not only means that smarter people have anatomically different brains, but they seem to have brains that work more efficiently as well. Emiliano Santarnici of Harvard Medical School explains: "Even if the brain had the right exoskeleton to achieve high performance levels, it wouldn't matter without an internal computer to regulate how energy is saved, and when resources are allocated at each moment." Santarniki's study suggests that magnetic stimulation may increase brain processing efficiency, and also underscores the importance of flexibility, or the ability to change. Some people may have brains that are inherently more flexible and better able to learn.

This is not to mention the genetic aspect. Although we know that hundreds of genes contribute to intelligence, it can take a long time to discover the nuances in their effect. But even then it will not be easy to find the center responsible for intelligence, the richest human trait found in the brain, which in turn is the most complex and mysterious thing known in the universe.

What happens when we think?

Think about the thought process, and it won't be long before your mind becomes confused. Ideas usually come naturally, but determining exactly what those ideas are is a more complex process. Previously, ideas were considered non-physical entities separate from the biological material of the brain. Now, we know that all our thoughts, whether simple or abstract, are the result of electrical signals traveling in the brain network of 86 billion neurons. Researcher Ethan Solomon of the University of Pennsylvania tried to simplify the concept of thinking by saying, "What the thought process represents to me is simply the process of converting input into results by the brain."

But if you ask a hundred neuroscientists about the definition of thought process, you'll get a hundred different answers, says researcher Evges Chesstig of the University of California, Berkeley. "Thinking is an umbrella term that falls under many different cognitive processes," she says. Some thoughts take the form of images, others are made up of words, and many are born in the unconscious level, without even realizing it.

The latest neurological studies have given us the opportunity to pick up the electrical signals that underlie thinking. It showed that even simple primitive thoughts involve a huge amount of activity, with different brain regions being excised and sending information to other regions, and some "central" areas directing the flow of that information.

The harder the process of remembering, the more active the prefrontal cortex, and the longer the response lasts, due to the time it takes for that region to activate other brain regions such as the networks in which memories are stored.

Last year, for example, Shsteig and her colleagues were able to record the journey individual thoughts take in the brain by measuring certain electrical signals when study subjects were asked to remember and say a word. The first areas to show electrical activity were the visual and auditory cortex, which receives signals from the eyes and ears. The brain's command center, the prefrontal cortex, then began to be active.

The harder the process of remembering, the more active the prefrontal cortex becomes, and the longer the response lasts, because of the time it takes for that region to activate other brain regions such as the networks where memories are stored. Finally, the motor cortex is activated to generate a spoken response. Surprisingly, this happens before the prefrontal cortex decides to respond. "That's why we sometimes start talking before we know what we want to say," says Schsteig.

The prefrontal cortex helps coordinate thought processes, but the signals in question also need to be coordinated. This is the function of brainwaves, which are waves of neural activity that oscillate at different frequencies through the brain. Solomon's research revealed that during a memory test, low-frequency theta waves in different brain regions involved become coordinated, and this synchronization may allow information to be communicated between regions.

Our new ability to monitor individual thoughts means that mind readers are no longer just fantastic. Earlier this year, brain-mounted electrodes were used to translate brainwaves into words spoken by a computer. Such techniques may help people with confinement syndrome, a condition in which the patient is awake and conscious but unable to communicate verbally with others due to being completely paralyzed of all his voluntary muscles except those of the eyes. All thanks to the power of thinking.

هل أنت شخص يميني أو يساري الدماغ؟

ربما اعتقدت من قبل أنك شخص يميني أو يساري الدماغ، أي يغلب عليك السمات العقلانية والمنطقية، أو الإبداعية والحيوية. ورغم جاذبية هذا المفهوم، فإنه أيضا محض خرافة. من السهل معرفة سبب نشوء هذه الفكرة. ففي حقبة الستينيات من القرن العشرين، اكتشفنا أن بعض الوظائف تحدث فقط على جانب واحد من الدماغ. إذ إن معظم الناس يعالجون اللغة في النصف الأيسر من الدماغ، بينما يضطلع النصف الأيمن من الدماغ في معالجة العواطف. وسرعان ما قيل إن النصف الأيسر يسيطر على المهام التي تشمل المنطق، واللغة، والتفكير التحليلي. في حين أن الجانب الأيمن من الدماغ هو المسؤول عن التحكم في العواطف، والذوق الموسيقي، والميل للتصرف باندفاع. ومنذ ذلك الحين ظهرت المقولة الشهيرة إن شخصيتك يُمكن أن تتحدد من خلال أي جانب من دماغك يهيمن على أفعالك.

بيد أن الحقيقة مختلفة بعض الشيء. فعلى سبيل المثال، على الرغم من أن النصف الأيسر من الدماغ هو المسؤول عن إصدار الكلمات التي قد تتسم بالتعقيد، يسمح النصف الأيمن بفهم المحتوى العاطفي والمجازي لتلك الكلمات، إذ إنه يمنحك بعض المهارات اللغوية. ومن ناحية أخرى، يُنشط التفكير الإبداعي شبكة واسعة من الخلايا التي لا تحفز أيًّا من نصفي الدماغ.

علاوة على ذلك، لا يوجد دليل على أن أحد جانبي الدماغ أكثر نشاطا من الآخر. فقد أجرى جيفري أندرسون من جامعة يوتا فحوصات شملت أدمغة أكثر من ألف شخص، أثناء قيامهم بأداء مهام مختلفة، وكشفت النتائج أن أيًّا منهم لم يظهر هيمنة لجانب واحد من الدماغ على حساب الآخر.

إننا جميعا نستخدم كل أجزاء أدمغتنا طوال الوقت، لكن هناك من يعتمد أكثر على الأنظمة الدماغية العلوية أو السفلية بعض الشيء، ويؤثر هذا بالتبعية على سلوكياتنا

من الأعلى إلى الأسفل

ثمة أفكار أخرى سائدة حول طريقة عمل الدماغ. إذ ترى "نظرية الأنماط الإدراكية" التي وضعها ستيفين كوسلين من جامعة هارفارد أن طريقة تفكيرنا تتحدد بما إذا كانت أدمغتنا أمامية أم خلفية (مخطط صفحة 37). جدير بالذكر أن الأجزاء العلوية من أدمغتنا مسؤولة عن إعداد وتنفيذ المخططات وإعادة النظر فيها إذا سارت بشكل خاطئ. أما الأجزاء السفلية فهي مسؤولة في معظمها عن معالجة مُدخلات الحواس وتصنيف الأشياء والوقائع وإضفاء معنى عليها.

ويقول كوسلين إننا جميعا نستخدم كل أجزاء أدمغتنا طوال الوقت، لكن هناك من يعتمد أكثر على الأنظمة الدماغية العلوية أو السفلية بعض الشيء، ويؤثر هذا بالتبعية على سلوكياتنا. فالشخص الذي تهيمن الأنظمة الدماغية العلوية على دماغه سيكون أكثر إبداعا وأكثر ميلا إلى المغامرة، لكنه يصبح غير كفء أحيانا لأنه لا يُحدث خططه بناء على الظروف الراهنة. في المقابل، يفكر الشخص الذي تهيمن الأنظمة الدماغية السفلية على دماغه كثيرا في تفاصيل خططه، لكنه أقل ميلا لبَدء المشاريع والمخططات المعقدة.

مع ذلك، يفترض أندرسون أن شخصياتنا تتكوّن على الأرجح من الطريقة التي تتصل بها الأنظمة الدماغية المختلفة ومدى ثراء الروابط بينها. فعلى سبيل المثال، غالبا ما يتأثر الأشخاص المنفتحون على خوض تجارب جديدة للغاية (وتنتابهم القشعريرة) عند مراقبتهم لغروب بديع للشمس. ويُظهر التصوير العصبي للدماغ أن لدى هؤلاء الأشخاص روابط كثيرة بين الأجزاء المسؤولة عن معالجة المعلومات الحسيّة والأجزاء المسؤولة عن الوجدان أو الضمير.

يبدو أحيانا وكأن دماغك قد توقف عن العمل عندما تستريح. لكن ذلك ليس صحيحا. فطالما أنك حي، ستستمر خلاياك العصبية في العمل بنشاط

ويقول أندرسون إن بمقدورنا الاستفادة من هذه المعلومات بتوظيفها في آليات التعلّم العميق والذكاء الاصطناعي التي يمكنها تقديم تنبؤات دقيقة حول السمات الشخصية للمرء استنادا إلى التصوير العصبي للدماغ. مضيفا: "لا يتعلق الأمر بما إذا كان المرء يستخدم الجزء الأيسر أم الأيمن من الدماغ أكثر، وإنما بالفوارق الدقيقة في الروابط التي تصل بين جميع أجزاء الدماغ".

هل يتوقف دماغك عن العمل؟

يبدو أحيانا وكأن دماغك قد توقف عن العمل عندما تستريح. لكن ذلك ليس صحيحا. فطالما أنك حي، ستستمر خلاياك العصبية في العمل بنشاط. يقول دنيز فاتنسيفر، وهو عالم أعصاب إدراكي في جامعة فودان الصينية: "يعالج دماغك الكثير من الأشياء، حتى عندما لا تفعل ظاهريا أيّ شيء على الإطلاق". لا يمكن بأيّ حال تصور إمكانية توقف الدماغ. فقد كان الاستعداد الدائم في كل اللحظات مسألة حياة أو موت عند أجدادنا. ربما حاليا لا يشغل بال معظمنا هجمات الفهود المفاجأة من بين الشجيرات، لكن ما زال علينا البقاء في حالة تأهب حتى لا نتعرض للخطر أو تضيع علينا الفرص، ويتطلب هذا عقلا يعمل على الدوام.

في التسعينيات، لاحظ علماء الأعصاب أنه رغم تمدد الأشخاص في سكون مغلقين أعينهم عند إجراء التصوير العصبي، أظهرت أدمغتهم مستويات مفاجئة من النشاط. وسرعان ما حدد الباحثون أجزاء الدماغ الأكثر نشاطا خلال فترات الراحة، وأطلقوا عليها اسم "شبكة الوضع الافتراضي" أو (Default Mode Network). تُظهر هذه الشبكة نشاطا ضعيفا عندما نقوم بمهام تتطلب انتباهنا، لكنها تنشط للغاية عندما لا نفعل أيّ شيء على الإطلاق، سامحة لعقولنا بالشرود.

تُشير بعض الأدلة إلى أن "شبكة الوضع الافتراضي" مسؤولة عن التفكير في التجارب السابقة والتخطيط للمستقبل. ومن هذا المنطلق، تعد تلك الحالة ضرورية لأن أحلام اليقظة واحدة من القدرات التي تميزنا عن باقي الحيوانات. لكن مهام "شبكة الوضع الافتراضي" تتجاوز ذلك بكثير. أثبت فاتنسيفر وزملاؤه في عام 2017 أنها السبب وراء قدرتنا على أداء الأمور الروتينية دون انتباه منا، مثل ربط شريط الحذاء أو القيادة على طول طريق مألوف، أيّ إنها تُمثّل "وضع الطيار الآلي" لدينا.

إيقاف التشغيل

يتحوّل الدماغ إلى خلية من النشاط خلال النوم أيضا. وبمجرد فقدان الوعي، يبدأ الدماغ العمل على جميع المهمات مثل طرد الجزيئات السامة (الفضلات) وتنظيم مستويات الهرمونات وبناء الأحلام، والتي يُعتقد أنها توفر بيئة آمنة لمحاكاة سلوكيات جديدة من شأنها مساعدة المرء خلال فترة يقظته. كما يقوم الدماغ النائم بأرشفة بعض التجارب لاستحضارها في وقت لاحق.

حتى عندما يكون شخص ما في حالة إنباتية وفاقدا للوعي وغير متجاوب بوضوح لفترة طويلة، تواصل دماغه العمل بقدر معين. فعلى سبيل المثال، عندما يُطلب من أشخاص في تلك الحالة تخيل أنفسهم وهم يلعبون التنس، يزداد تدفق الدم في أجزاء الدماغ المسؤولة عن المهارات الحركية، وهو ما يعني أن الخلايا العصبية في تلك المناطق في حالة نشاط كبير. في إحدى الحالات، نشطت تلك الأجزاء عند مريض طُلب منه الرد على مجموعة أسئلة إجاباتها بنعم أو لا.

لا تتوقف الخلايا العصبية تماما عن العمل إلا عند الموت. وحتى في تلك الحالة الاستثنائية، توجد دفعة نهائية من النشاط تنتجها الدماغ البشرية، كما أظهر جيد هارتنغز وزملاؤه بجامعة سينسيناتي في أوهايو مؤخرا لأول مرة في البشرية. فعندما يتوقف القلب عن ضخ الدم إلى الدماغ، حارما إياه من الأكسجين، تعتمد الخلايا العصبية على طاقة احتياطية مخزنة لمواصلة العمل لمدة تصل إلى ثلاث دقائق قبل أن تنتج دفعة أخرى أخيرة من الطاقة الكهروكيميائية، وعندها فقط يتوقف الدماغ نهائيا عن العمل.

غالبا ما ننسى أن الأمعاء جهاز استقبال حسيّ، حيث يستكشف العناصر الغذائية والسموم ومسببات الأمراض الداخلة إلى الجسم، ويرحّل هذه المعلومات إلى أدمغتنا

هل تؤثر الأمعاء على الدماغ؟

نشعر في بعض المواقف بألم في أمعائنا، يدفعنا إلى اتخاذ قرارات بناء على هذا الإحساس. وربما يكون هذا الأمر أكثر واقعية مما نتصور. فعلى سبيل المثال، يرتبط الإحساس بالغثيان بالحكم القاسي على بعض الانتهاكات الأخلاقية [فهو كناية عن الشعور بالاشمئزاز]. وما هذه إلا واحدة من الطرق العديدة التي تؤثر بها الأمعاء على ما يدور في رؤوسنا.

We often forget that the gut is a sensory receiver, exploring nutrients, toxins, and pathogens entering the body, and relaying this information to our brains. The gut contains about 500 million neurons that coordinate digestion. The gut is also home to about 2 kilograms of bacteria, which create our gut microbiome, which affect every organ in the body including the brain. A large body of studies in mice has also shown that changing gut bacteria can change behavior. This made the mice isolated and asocial in some cases.

The microbiome is particularly important in childhood, when the brain is still developing. For example, mice that lack a type of bacteria called bifidobacterium in their gut during infancy are poor at gaining and learning new experiences. Evidence for this is also mounting in humans. One imaging study concluded that consuming fermented milk containing different types of live bacteria had a significant impact on resting people's brain activity and their reactions to seeing faces that show certain emotions. A study this year in Belgium involving 1054,<> people found that certain types of gut bacteria are rare in people with depression.

There are also exciting indications that certain neurological conditions such as autism and Alzheimer's disease may have originated in the gut. In Parkinson's disease, synuclein fibres, a type of protein found in abundance in this disease and a hallmark of the disease, first begin to appear in the intestines before spreading into the brain. We still don't know what causes it, but a microbe or toxin (a protoxin biotoxin) may be unknown. In epilepsy, changes in the microbiome may explain why high-fat diets (such as keto) prevent seizures in some people.

Research on the relationship between the gut and the brain is still in its infancy, but it has sparked the idea of developing drugs that target the microbiome to improve our mental health, called psychobiotics. John Crayan of University College Cork in Ireland thinks this is an exciting possibility, but we still need extensive work to figure out which bacteria are beneficial for each particular case and how to grow them in the gut.

How bacteria actually affect the brain is also still a mystery, but the picture is clearer. Tens of trillions of bacteria in our gut form a cell of metabolic activity, which produces a huge amount of chemicals that our bodies can absorb. Current research is focused on figuring out exactly which one reaches and affects the brain. Some bacteria feed on GABA or gamma-aminobutyric acid, a brain chemical that has an effect on depression.

It's probably surprising that our brains are affected by what's in our gut, but it wouldn't be so strange if you consider that these microbes have always been with us, says Crean. "I consider them friends with social benefits because they actually influence the social brain during childhood and development. This is also a very important relationship and I think it was an evolutionary tool."

What is the brain made of?

A few years ago, scientists took cells from the human brain and inoculated mice with them. A year later, those cells multiplied and the mice became smarter, learning more efficiently than mice with normal brains. This probably doesn't surprise you until you know that those brain cells weren't neurons. As brain cell building continues, neurons have the lion's share. There are about 86 billion of these slender cells that carry electrical impulses in the brain, helping us control our bodies and keep thinking. However, there are many electrically inactive brain cells, glial cells that number at least the same number of neurons. The brains of mice have been inoculated with the stellar type of glial cells, which indicates their importance in learning processes, and this is not the first time scientists have reached this conclusion.

Astroglia take care of the environment around neurons, controlling levels of chemicals known as neurotransmitters, and also helping to repair damage.

These glial cells were previously considered mere fillers for voids, but that has changed today. Anne Kwok, executive director of the British Neuroscience Society, said: "There is growing evidence that it is more than just an adhesive. These cells are unknown soldiers inside the brain." There are several types of these cells: some of them, for example, are small and called microglia, and they roam the brain, devouring foreign substances, protecting neurons.

Astroglia also take care of the environment around neurons, controlling levels of chemicals known as neurotransmitters, and also helping to repair damage. There is growing evidence that these cells also play a role in the development of human intelligence; we know that young children are released with many connections between their neurons, and that these connections are gradually trimmed to create fewer stronger signaling pathways; astroglia appear to have a role in this trimming process.

Ed Lane, of the Allen Institute for Brain Science in Seattle, said: "While neurons are still very important, glial cells appear to have a role in determining electrical gain in the brain system." It's not just about cells, spaces also have a role. Deep in the brain there are small chambers called ventricles, which produce fluid that floods brain cells. Every day, 500 milliliters of cerebrospinal fluid are produced that keeps things running and stable by providing supports and nutrients and driving waste away.

There is no doubt that there is more to discover. Last year, researchers identified a new type of brain cell they called "rose geran-type neurons" because they resemble the shape of rosehip fruit; they suggested they may only be present in the human brain. There are other secrets that Line's efforts to create a map of all types of brain cells may reveal, a painstaking discovery that tracks the genes expressed by each individual cell. He recently began studying the neocortex of the cerebral cortex, the outer part of the human brain, which handles higher processes and makes up about 80% of brain mass, and discovered 75 different types of cells in that cortex alone.

What makes some brains more resistant to weakness and wilting?

There's a shocking fact of life that as you get older your cognitive abilities begin to decline. Why do some people reach old age with only "fleeting moments of dementia" while others suffer from significant mental and mental decline?

The brain begins to shrink at the age of forty, with cells degrading faster in the frontal lobe, striatum nucleus, and hippocampus. They are areas that have their role in shaping our most complex thoughts, movements and memory. Your ability to resist the effects of this decline is likely to be related to your cognitive/cognitive reserve. This is something like a mental barrier that allows the brain to withstand the most damage before you start noticing changes in your cognitive abilities.

Cognitive reserve isn't just how much one has more neurons, but it also means how closely those cells are connected to each other across different networks in the brain. This allows the brain to make up for the deficiency when age-related deterioration or disease occurs, and helps redirect information so that the brain can continue to function at its best. This is a bit like increasing a computer's processing power, as many things can go wrong before you notice their slowdown.

The environment may also affect cognitive reserve. Higher levels of education provide one of the greatest degrees of increasing that reserve, while poor health conditions such as obesity and IR resistance reduce it. Many genes also help us fight cognitive decline. Small genetic differences are related to our susceptibility to Alzheimer's disease, as well as to how the brain employs energy reserves and reacts to injuries and pathogens.

Mind exercise

There are ways to improve cognitive reserve. One of the best ways is to continue your education throughout your life.

The shrinkage of the brain over time sounds engaging, but there is some good news. Although most brain cells are born after birth, our brains can generate certain types of neurons until the age of ninety and tenth decade of life. This ability may explain to some extent why the brains of some succeed in resisting the ravages of aging.

There are other ways to improve cognitive reserve. One of the best ways is to continue learning throughout your life, but there are other things that help, including playing an instrument, socializing, getting plenty of sleep, and mastering more than one language. However, do not rely on this too much; the proverb "a healthy mind is in a healthy body" has become true.

Steve Harridge, director of the Centre for Humanistic and Applied Physiological Sciences at King's College London (King's College, University of London), says that "if you're looking to maintain your mental health, you need to train and exercise." Regular training brings about noticeable improvements in memory, attention, processing speed, and executive functions such as planning and multitasking.

Don't leave it until it's too late. Richard Henson and his colleagues at the University of Cambridge have discovered that the things we do in middle age – outside of work and education – make a unique contribution to improving brain health as we age. However, the activities of retirees at the end of their lives have less impact. "Middle age seems like a good time to step in to get people to contribute to more activities — physical, intellectual/mental and social — that may have promising effects 20 or 30 years later," Henson says.

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Translation: Translation team.

This article is translated from New Scientist and does not necessarily reflect Meydan's website.