In 454, Emperor Valentinian III executed his brilliant but capricious commander Aetius, and a year later he himself was killed. The next twenty years proved to be a period of political chaos: no less than eight emperors were enthroned and deposed - either on the initiative of the Roman Senate aristocracy, or at the instigation of the Eastern emperor. On August 23, 476, German troops in Italy (which now formed the bulk of the Roman army) elected their commander Odoacer as king and deposed the last Western emperor, Romulus Augustulus (Augustulus’s government refused to allocate a third of the lands to the soldiers - that’s exactly how much the Roman “allies” in Gaul received) .

This event marked the end of the Roman Empire in the West. Formally, the entire territory of the empire was now ruled by the eastern emperor Zeno. In fact, Odoacer, hated by the Roman aristocracy and not recognized by Constantinople, became the independent ruler of Italy.

Ostrogoths in Italy

Zeno did not have the opportunity to reconquer Italy, but he still took revenge on Odoacer. The Ostrogoths, defeated and enslaved by the Huns, eventually, like the Visigoths, moved into the Balkan provinces of the empire. In 488, Zeno convinced their leader, Theodoric, to march from Moesia (modern Serbia) to Italy. This was a clever move on the part of the emperor: whoever won in Italy, the Eastern Empire would at least get rid of the last tribe of barbarians that was still in its provinces.

By 493, the Ostrogoths occupied Italy, Odoacer was dead (according to stories, Theodoric himself killed him). Formally, Theodoric, as the emperor's viceroy, received the title of patrician, but in reality he remained as independent as the other barbarian leaders.

Roman Empire in the East: Justinian

The departure of the Ostrogoths to Italy liberated the eastern part of the Roman Empire from the last barbarian tribe that invaded its territory in the 5th century. In the next, VI century. Graeco-Roman civilization once again demonstrated its vitality, and the military and administrative organization of the empire proved remarkably flexible and capable of responding effectively to the demands of the situation. The great cities of the empire - Alexandria, Antioch, Caesarea and Jerusalem - did not lose their power. The merchants of these cities continued to outfit ships throughout the Mediterranean and down the Red Sea to East Africa, Ceylon and even further.

Byzantine (i.e. Roman) gold coin- solidus (on which the image of the emperor was minted) - went throughout the civilized world, from Ireland to China. Caravans crossed the vast Asian continent along a route equipped with numerous inns. One of these caravans smuggled silkworms out of China, and soon their own silk production flourished in Cyprus and other parts of the empire. For the rich townspeople, life remained much the same as it had been for many centuries. Young people received both classical and religious education at academies and universities. Christianity, which had been under the protection and patronage of the state for three centuries, showed its wealth in hundreds of churches, decorated with luxurious lamps, sculptures and mosaics.

However, Constantinople, the capital of the empire, became the largest and richest city. Mindful of the fate that befell Rome in 410, the emperors surrounded Constantinople with a system of defensive walls with towers that protected it from both land and sea. These walls successfully withstood all attacks until 1204, when the Crusaders treacherously broke into the city and captured it. As before in Rome, so now in Constantinople, the emperors had to pursue a certain policy towards the inhabitants of the huge capital. As before, “bread and circuses” meant a public demonstration of the authorities’ interest in supporting the poorest masses. The fans at the hippodrome (a huge stadium for horse racing, chariot races and baiting of wild animals) were divided into “green” and “blue”. However, these were not just supporters of different teams, but also original parties that differed in political and religious views and were usually at odds. In 532, they united during anti-government riots and terrorized the city for several days. Justinian's advisers strongly recommended that he go into hiding. However, Justinian's wife, Theodora, convinced him to restore order, and the professional soldiers of the commander Belisarius mercilessly dealt with the rebels.

These riots were the last internal crisis of Justinian's reign. He went on to rule the empire as effectively as his predecessors, and even more autocratically, largely thanks to the advice of Empress Theodora. Justinian had complete control over the imperial bureaucracy and imposed taxes at his discretion. As supreme legislator and judge, he initiated the compilation of a code of imperial laws, the famous Corpus juris civilis(Vault civil law). In the first of its three parts, Codex Justinianus(Code of Justinian), all the decrees of the emperors from the time of Hadrian (117–138) to 533 were collected. Later edicts were introduced under the name novel lae(New laws). It was this last part of the “corpus” that contained the justification for the absolute power of the emperor. The second part, the Digests, or Pandects, in 50 books, included excerpts from the works and opinions of Roman jurists related to civil and criminal legislation. The third part, Institutions, was an abridged version of the first two parts, that is, a kind of law textbook. Probably no text of a secular nature had such a wide and lasting influence in Europe as Corpus juris civilis. In the subsequent period of the history of the Eastern Empire, it served as a comprehensive and rationally constructed system of legislation and the study of law. But the Code played a much more important role in the West, becoming the basis of canon and ecclesiastical law of the Roman Catholic Church. From the 12th century Justinian's legislation gradually began to dominate secular courts and law schools and eventually almost replaced common law in most European countries. Thanks to Roman law, Justinian's autocracy served as the intellectual basis for the absolutism of Western monarchies in the 16th, 17th, and 18th centuries. Even in countries like England, where customary local law has survived, the development of systematic and rational jurisprudence, legal science and legal philosophy would probably have been impossible without the historical model - Corpus juris civilis .

A visible expression of the greatness of the emperor and the Christian church (which was actually headed by the emperor) was the reconstruction of the Church of St. Sophia (Divine Wisdom), which burned down during the riots of 532. Justinian invited the best architects, mathematicians and craftsmen from all over the empire to the capital, who erected the most grandiose and the magnificent temple of Christendom. Even now, its huge flat dome dominates the panorama of Istanbul (the current name of Constantinople). Justinian's court historian Procopius of Caesarea left us a description of the stunning interiors of the temple, written in the characteristic rhetorical style of the time; it allows us to understand the specifics of Byzantine religiosity in the 6th century.

An unusual amount of sunlight penetrates into it, which is also reflected from the marble walls. Indeed, one could say that it is not so much illuminated by the sun from the outside as it shines from the inside - its altar is bathed in such an abundance of light... Its entire ceiling is entirely trimmed with pure gold - which makes its beauty majestic. However, most of all, the light is reflected from the stone surfaces, competing with the shine of gold... Who has enough words to adequately describe the galleries of the female side and the colonnades of the side chapels that surround the temple? Who can describe all the beauty of the columns and colored stones that adorn it? You can imagine that you are in the middle of a meadow, replete with the most beautiful flowers: some of them are distinguished by an amazing purple color, others are green, others glow crimson, others are dazzling white, and others, like an artist’s palette, sparkle with the most different colors. And when a person enters this temple to offer prayer, he immediately realizes that it was not through human strength or human skill, but through the care of God that this creation was born so beautiful. And then his spirit rushes to God and rises, feeling that He cannot be far away, but must willingly remain in the dwelling that He has chosen for Himself 24.

Majestic splendor, softened by beauty, light and divine love - such was the legacy of the emperor, who considered himself God's vicegerent on earth. This largely explains the long existence of the Roman Empire in the East.

The reconstruction shows what part of the great city looked like Ancient Rome.

The model of Ancient Rome shows the island of Tiberina, the Circus of Massimo and the Theater of Marcellus.

Thermae (that is, baths) of Caracalla, which once consisted of huge halls, including gymnastics and massage rooms, porticoes, fountains, gardens, and a library. There were pools with cool, warm and hot water.

A section of an ancient city road that has survived to this day. The road leads to the Arch of Titus.

Modern European civilization began and grew around the Mediterranean Sea. It is enough to look at a map or a globe to understand that this place is unique. The Mediterranean Sea is quite easy to navigate: its shores are very winding, there are many islands, especially in the eastern part, and they are located close to each other. And ships plied the Mediterranean Sea back in the days when the speed of sailing depended on the amount of bread and beer eaten and drunk by the rowers, and the sail was considered a fashionable novelty.

The inhabitants of the Mediterranean coast recognized each other early. Enterprising merchants and pirates (usually these were the same people) introduced the surrounding barbarians to the ingenious inventions of the Egyptians and Babylonians. This and complex rituals veneration of mysterious gods, and the technique of making metal weapons and beautiful pottery, and the amazing art of recording human speech.

Two and a half thousand years ago, the most developed people in the Mediterranean were the Greeks. They knew how to make very beautiful things, their merchants traded along the entire coast, and their warriors were considered almost invincible. From Spain to Arabia, many people spoke the Greek dialect Koine ("common"). Poems, plays and learned treatises, letters to friends and reports to kings were written on it. At the most different nations the townspeople went to gymnasiums, watched theatrical performances on Greek, running and wrestling competitions were held according to Greek models, and the palaces and temples of even minor kings and gods were decorated with Greek statues.

But the Greeks did not create an empire. They did not strive to create it, just as, for example, ants do not strive to combine their cozy homes into one super anthill. The Greeks were accustomed to living in small communities - poleis. They felt like one people, but first of all they remained Athenians, Spartans, Ephesians, Phocians, etc. The newcomers could live in someone else's polis for several generations, but never became its citizens.

Rome is another matter. The Romans were excellent organizers. They fought courageously, did not get discouraged by failures, and also knew how to negotiate.

Initially, people from different tribes settled on the Roman hills, however, they quickly found mutual language and turned into respected patricians. With later settlers - plebeians- The patricians did not want to share power for a long time, but in the end they came to an agreement with them. By the time Rome began its large-scale conquests, patricians and plebeians had already merged into a single Roman people.

Gradually, its neighbors were drawn into the composition of this people - Italians. However, the largest source of replenishment of the Roman nation were foreign slaves.

In Greece, slaves were freed only in exceptional cases; in Rome this was rather the rule. Having received freedom, the former slave became freedman- a free person, although not independent, dependent on the former owner. Power over free people, from the Roman point of view, was much more honorable than power over slaves. Later, this view was inherited by the peoples who settled on the ruins of the Roman Empire. “In my country, government officials pride themselves on being servants of the public; to be its owner would be considered a disgrace,” said the famous English politician Winston Churchill in the 20th century.

It was also profitable to free slaves: for liberation, the master could set such a ransom that he would buy several slaves with the money received. In addition, Roman senators, who were not allowed by custom to earn money through “low” occupations, bought merchant ships and shares in companies through freedmen.

As for the former slaves, their grandchildren no longer bore the mark of slave origin and were equal to the freeborn.

What's the lesson here?

Only a big people can prove themselves. Thanks to the fact that the Romans did not hiss at the newcomers and did not shout “all sorts of people are here,” the Roman people remained numerous enough for several centuries to not only subjugate huge densely populated territories, but also keep them in obedience. If the Romans had been prone to disunity, like the Greeks, there would have been no trace of the Roman Empire. This means that there would not have been such a Europe as we see today, and in general the whole history would have gone differently.

And yet, every coin has two sides.

The new citizens adopted Roman customs. But they themselves influenced the indigenous Romans, who gradually dissolved among numerous strangers. The descendants of the freed slaves no longer wanted to risk their lives defending the Roman Empire. This ultimately led to her death.

True, this happened several centuries later. By that time, the Romans had left such a bright mark on history that it was no longer possible to erase it. (476 is considered to be the end date of the existence of the Western Roman Empire. The Eastern, called Byzantium, existed for another thousand years.)

Figures and facts

- The population of Ancient Rome at the peak of its power was a million people. Europe reached the same level only after 2000 years: at the beginning of the twentieth century, only a few European cities had a million inhabitants.

The Roman Empire, according to various estimates, built from 1500 to 1800 cities. For comparison: at the beginning of the twentieth century, throughout the entire territory Russian Empire there were about 700 of them. Almost all the major cities of Europe were founded by the Romans: Paris, London, Budapest, Vienna, Belgrade, Sofia, Milan, Turin, Bern...

14 aqueducts ranging from 15 to 80 kilometers long supplied water to the population of Ancient Rome. From them the water went to fountains, pools, public baths and toilets and even into individual houses of wealthy citizens. It was a real plumbing. In Europe, similar structures appeared more than 1000 years later.

The total length of the roads of the Roman Empire was, according to various estimates, from 250 to 300 thousand kilometers - this is seven and a half equators of the Earth! Of these, only 14 thousand kilometers ran through Italy itself, and the rest - in the provinces. Apart from dirt roads, 90 thousand kilometers were real highways - with hard surfaces, tunnels and bridges.

The famous Roman sewer - Cloaca Maxima - was built in the 7th-6th centuries BC and existed for 1000 years. Its dimensions were so large that workers could move by boat through the underground sewer channels.

Details for the curious

Roads of the Roman Empire

The powerful Roman Empire, huge in area (there are 36 states on its territory today) could not exist without roads. The ancient Romans were famous for their ability to build first-class roads, and they made them to last for centuries. It’s hard to believe, but part of the road network they built 2000 years ago in Europe was used for its intended purpose until the beginning of the twentieth century!

The Roman road is complicated engineering structure. First, they dug a trench 1 m deep and drove oak piles into the bottom (especially if the soil was damp). The edges of the trench were reinforced with stone slabs and inside it a “layer cake” was created from large stone, smaller stone, sand, stone again, lime, and tile powder. On top of this travel pillow actually put it road surface- stone slabs. Don't forget: everything was done by hand!

Along the edges of Roman roads there were stone mileposts. There were even road signs- tall stone columns indicating the distance to the nearest settlement and to Rome. And in Rome itself, the zero kilometer with a memorial sign was laid. There was a postal system on all highways. The speed of delivery of urgent messages was 150 km per day! Chernobyl was planted along the roads so that travelers could put its leaves in their sandals if their feet were sore.

For the Romans, nothing was impossible. They built roads on mountain passes and in the desert. In Northern Germany, ancient builders managed to lay cobblestone roads three meters wide even through swamps. To this day, tens of kilometers of Roman roads have been preserved there, along which a truck can drive without risk. And during the empire, these were military roads that could withstand heavy military equipment- siege weapons.

Action potential or nerve impulse, a specific response that occurs in the form of an exciting wave and flows along the entire nerve pathway. This reaction is a response to a stimulus. The main task is the transmission of data from the receptor to the nervous system, and after that it sends this information to the desired muscles, glands and tissues. After the passage of the pulse, the surface part of the membrane becomes negatively charged, while its inner part remains positive. Thus, a nerve impulse is a sequentially transmitted electrical change.

The exciting effect and its distribution are subject to physico-chemical nature. The energy for this process is generated directly in the nerve itself. This happens due to the fact that the passage of an impulse leads to the generation of heat. Once it has passed, the attenuation or reference state begins. In which just a fraction of a second the nerve cannot conduct a stimulus. The speed at which the pulse can be delivered ranges from 3 m/s to 120 m/s.

The fibers through which excitation passes have a specific sheath. Roughly speaking, this system resembles electrical cable. The composition of the membrane can be myelin or non-myelin. The most important component of the myelin sheath is myelin, which plays the role of a dielectric.

The speed of the pulse depends on several factors, for example, on the thickness of the fibers; the thicker it is, the faster the speed develops. Another factor in increasing conduction speed is the myelin itself. But at the same time, it is not located over the entire surface, but in sections, as if strung together. Accordingly, between these areas there are those that remain “bare”. They cause current leakage from the axon.

An axon is a process that is used to transmit data from one cell to the rest. This process is regulated by a synapse - a direct connection between neurons or a neuron and a cell. There is also a so-called synaptic space or cleft. When an irritating impulse arrives at a neuron, neurotransmitters (molecules) are released during the reaction process. chemical composition). They pass through the synaptic opening, eventually reaching the receptors of the neuron or cell to which the data needs to be conveyed. Calcium ions are necessary for the conduction of a nerve impulse, since without this the release of the neurotransmitter does not occur.

The autonomic system is provided mainly by non-myelinated tissues. Excitement spreads through them constantly and continuously.

The transmission principle is based on the occurrence electric field, therefore, a potential arises that irritates the membrane of the adjacent section and so on throughout the fiber.

In this case, the action potential does not move, but appears and disappears in one place. The transmission speed through such fibers is 1-2 m/s.

Laws of conduct

There are four basic laws in medicine:

• Anatomical and physiological value. Excitation is carried out only if there is no violation in the integrity of the fiber itself. If unity is not ensured, for example, due to infringement, drug use, then the conduction of a nerve impulse is impossible.
• Isolated conduction of irritation. Excitation can be transmitted along a nerve fiber without in any way spreading to neighboring ones.
• Bilateral conduction. The path of impulse conduction can be of only two types - centrifugal and centripetal. But in reality, the direction occurs in one of the options.
• Non-decremental implementation. The impulses do not subside, in other words, they are carried out without decrement.

Chemistry of impulse conduction

The irritation process is also controlled by ions, mainly potassium, sodium and some organic compounds. The concentration of these substances is different, the cell is negatively charged inside itself, and positively charged on the surface. This process will be called potential difference. When a negative charge oscillates, for example, when it decreases, a potential difference is provoked and this process is called depolarization.

Stimulation of a neuron entails the opening of sodium channels at the site of stimulation. This may facilitate the entry of positively charged particles into the cell. Accordingly, the negative charge is reduced and an action potential or nerve impulse occurs. After this, the sodium channels close again.

It is often found that it is the weakening of polarization that promotes the opening of potassium channels, which provokes the release of positively charged potassium ions. This action reduces the negative charge on the cell surface.

The resting potential or electrochemical state is restored when potassium-sodium pumps are activated, with the help of which sodium ions leave the cell and potassium ions enter it.

As a result, we can say that when electrochemical processes are resumed, impulses occur that travel along the fibers.

Information is transferred between neurons like current in wires. Electrical impulses are transmitted from cell to cell, from the dendrite in which they originate to the axon through which they pass. But there is also a difference from electrical networks- impulses are transmitted not through electrons, but through ions.

Synapse

Despite their large number, neurons never touch each other. But electrical impulses cannot be transmitted unless there is physical contact. Therefore, messages transmitted from neuron to neuron must be converted from electrical to another form. The nervous system uses chemicals to transmit information between neurons.

A synapse is a point of contact between two neurons or between a neuron and a cell receiving a signal.

The synaptic space has the shape of a cleft. When an electrical impulse arrives at a neuron, it releases chemical molecules called neurotransmitters from the synapse. Through diffusion, they move across the synaptic cleft and enter the receptors of another neuron specially designed for them. As a result, another electrical impulse occurs.

Two types of neurotransmitters

The brain produces about fifty types of neurotransmitters, which can be divided into two types. Excitatory mediators contribute to the generation of a nerve impulse. Inhibitory neurotransmitters, on the contrary, slow down its occurrence. In most cases, a neuron releases only one type of neurotransmitter.

Excitation limit

Each neuron is capable of receiving hundreds of messages per second. He judges the degree of its significance and makes a preliminary analysis of it. In a neuron, excitatory impulses are added and inhibitory impulses are subtracted. For a neuron to generate its own impulse, the resulting sum must be greater than a certain value.

The Role of Repetition

Similar ideas, similar memories fire the same neurons and synapses. Frequently used synapses work faster. Therefore, we quickly remember what we have seen or repeated several times. However, these connections can disappear if they are not used enough, and new ones can appear in their place.

Glial cells

Another type of nerve cell is glial cells. There are 10 times more of them than neurons themselves. They are called “nurses of neurons” because they contribute to their nutrition, removal of their waste products and protection from external enemies. But the latest research suggests that they are needed for more than just caring for neurons. Apparently, they are also involved in information processing, in addition, they are necessary for memory function!

Nerve fibers

The processes of neurons are surrounded by membranes and combined into bundles called nerve fibers. The number of nerve fibers in various nerves ranges from 10 2 to 10 5.

The nerve fiber sheath is made up of glial cells and facilitates the passage of nerve impulses throughout the body. It's called the myelin sheath.

The role of hormones in brain function

To exchange information, the brain uses special chemical compounds - hormones. Some of them are produced by the brain itself, and some by the endocrine glands. Hormones cause various physiological reactions.

3. HUMAN BRAIN

The outer layer of the brain consists of two cerebral hemispheres, which hide deeper formations. The surface of the hemispheres is covered with grooves and convolutions, which increase their surface.

Main parts of the brain

The human brain can be roughly divided into three main parts:

forebrain

brain stem

cerebellum

Gray and white matter

The brain matter consists of gray and white areas. Gray areas are clusters of neurons. There are more than 100 billion of them, and they are the ones who process information. The white matter of the brain is made up of axons. Through them, information is transmitted that is processed by neurons. The inner part of the spinal cord also contains gray matter.

Brain nutrition

The brain needs nutrition to function properly. Unlike other cells in the body, brain cells can only process glucose. The brain also needs oxygen. Without it, mitochondria will not be able to produce enough energy. But since blood supplies glucose and oxygen to the brain, to maintain brain health, nothing should interfere with normal blood flow. If blood stops flowing to the brain, within ten seconds the person loses consciousness. Although the brain weighs only 2.5% of the body's weight, it constantly receives 20% of the blood circulating in the body and a corresponding amount of oxygen, day and night.

As a result of evolution nervous system humans and other animals arose complex information networks, processes in which are based on chemical reactions. The most important element the nervous system are specialized cells neurons. Neurons consist of a compact cell body containing a nucleus and other organelles. Several branched processes extend from this body. Most of these processes, called dendrites, serve as contact points for receiving signals from other neurons. One process, usually the longest, is called axon and transmits signals to other neurons. The end of an axon can branch multiple times, and each of these smaller branches is able to connect to the next neuron.

The outer layer of the axon contains a complex structure formed by many molecules that act as channels through which ions can flow both into and out of the cell. One end of these molecules, deflecting, attaches to the target atom. Energy from other parts of the cell is then used to push that atom out of the cell, while the process in the opposite direction brings another molecule into the cell. Highest value has a molecular pump that removes sodium ions from the cell and introduces potassium ions into it (sodium-potassium pump).

When a cell is at rest and not conducting nerve impulses, the sodium-potassium pump moves potassium ions into the cell and removes sodium ions out (imagine a cell containing fresh water and surrounded by salt water). Because of this imbalance, the potential difference across the axon membrane reaches 70 millivolts (approximately 5% of the voltage of a regular AA battery).

However, when the state of the cell changes and the axon is stimulated by an electrical impulse, the equilibrium on the membrane is disturbed, and the sodium-potassium pump begins to work in the opposite direction for a short time. Positively charged sodium ions enter the axon, and potassium ions are pumped out. For a moment, the internal environment of the axon acquires a positive charge. In this case, the channels of the sodium-potassium pump are deformed, blocking further sodium influx, and potassium ions continue to flow out, and the original potential difference is restored. Meanwhile, sodium ions spread inside the axon, changing the membrane at the bottom of the axon. At the same time, the state of the pumps located below changes, promoting further propagation of the impulse. A sharp change in voltage caused by rapid movements of sodium and potassium ions is called action potential. When an action potential passes through a certain point on the axon, the pumps turn on and restore the resting state.

The action potential travels quite slowly—no more than a fraction of an inch per second. In order to increase the speed of impulse transmission (since, after all, it is not good for a signal sent from the brain to take a minute to reach the hand), the axons are surrounded by a sheath of myelin, which prevents the influx and outflow of potassium and sodium. The myelin sheath is not continuous - at certain intervals there are breaks in it, and the nerve impulse jumps from one “window” to another, due to this the speed of impulse transmission increases.

When the impulse reaches the end of the main part of the axon body, it must be transmitted either to the next underlying neuron, or, if we're talking about about the neurons of the brain, through numerous branches to many other neurons. For such transmission, a completely different process is used than for transmitting an impulse along the axon. Each neuron is separated from its neighbor by a small gap called synapse. The action potential cannot jump across this gap, so some other way must be found to transmit the impulse to the next neuron. At the end of each process there are tiny sacs called ( presynaptic) bubbles, each of which contains special compounds - neurotransmitters. When an action potential occurs, these vesicles release neurotransmitter molecules that cross the synapse and bind to specific molecular receptors on the membrane of underlying neurons. When a neurotransmitter attaches, the balance on the neuron membrane is disrupted. We will now consider whether a new action potential arises with such an imbalance (neuroscientists continue to search for an answer to this important question still).

After neurotransmitters transmit a nerve impulse from one neuron to the next, they can simply diffuse, or undergo chemical breakdown, or return back to their vesicles (this process is awkwardly called recapture). At the end of the 20th century, an amazing thing was done scientific discovery- it turns out that drugs that affect the release and reuptake of neurotransmitters can radically change mental condition person. Prozac* and similar antidepressants block the reuptake of the neurotransmitter serotonin. It appears that Parkinson's disease is associated with a deficiency of the neurotransmitter dopamine in the brain. Researchers studying borderline states in psychiatry are trying to understand how these compounds affect human reasoning.

There is still no answer to the fundamental question of what causes a neuron to initiate an action potential - in the professional language of neurophysiologists, the mechanism of “firing” of a neuron is unclear. Particularly interesting in this regard are neurons in the brain, which can receive neurotransmitters sent by a thousand neighbors. Almost nothing is known about the processing and integration of these impulses, although many research groups are working on this problem. We only know that the neuron carries out the process of integrating incoming impulses and makes a decision whether or not to initiate an action potential and transmit the impulse further. This fundamental process controls the functioning of the entire brain. It is not surprising that this greatest mystery of nature remains, at least today, a mystery for science!