History of the study of the human brain

Nowadays, the study of the brain is very advanced (but not as much as one would like, because the human brain still hides many questions). Indeed, in the last 20 years, more progress has been made in the study of the brain than in all previous millennia.

The History of Brain Study is Fascinating. How has this organ been considered by different times and cultures? From prehistory to the present day, passing through ancient Egypt and the European Middle Ages, the brain has passed through different states of appreciation.

    History of human brain research

    In this article, we offer you a brief journey through the study of the human brain.

    The brain in prehistory: the beginning of trepanaciones

    The brain and the skull area were already important for men and women in the first millennium. The earliest manifestations of cranial surgery date back to no less than the 6th millennium BC.

    Many human remains were found with obvious signs of trepanation; famous is the case of the 12 graves found in Rostov del Don, Russia, where at least 3 people showed holes in their skulls that had obviously been made with sharp instruments. But the practice was very common in other regions of the world which, in theory, were not culturally connected: cases have also been found in Africa and South America, where the pre-Inca civilizations (III millennium BC .-C.) practiced trepanation to relieve migraine or epilepsy. and, in addition, they used coca or other vegetables to dull the pain.

    This raised the question: Were trepanations part of a ritual or were they performed for medical reasons? The first case would mean that, during prehistory, the brain enjoyed a capital importance in the religion of these first human communities. In any case, despite the low survival rate, there have been cases where the patient survived at least 4 years after the operation.

      In Egypt, the brain is not important

      Ancient Egyptian funeral rituals are rich and elaborate. First, the organs of the deceased were extracted and deposited in the so-called canopic vessels. Then the body was dried with baking soda. The mummy was buried, after various rituals, with its canopic vessels, as the organs had an exceptional post-mortem function.

      But was the brain also saved? The answer is no. Mummification officials extracted the corpse’s brain through the nostrils, by means of an iron hook, then the organ was thrown in the trash. This means, of course, that Egyptian religion placed no importance on the brain, nor assumed any important function in the afterlife.

      However, although he does not give it any spiritual value, there is evidence that the ancient Egyptians knew about the morphology of the brain and its relation to certain injuries or diseases. Thus, in the call Edwin Smith papyrus (2nd millennium BC), we find a detailed analysis where, for the first time, the importance of the central nervous system, as well as of the brain as master of the functions of the organism, is highlighted. The document is of major importance, because it constitutes the first medical testimony based on empirical and objective observation.

      In fact, it is believed that in ancient Egypt, trepanaciones were performed to treat migraines, epilepsy, and other ailments. And, still as in prehistory, many patients survived. In some cases, their pain may even be relieved, since trephination could be relatively effective in relieving pressure from the brain or draining bruises.

        The classical era and the foundations of the study of the brain in the West

        All Western medicine, until very recent times, was based on the principles of the Greek physician Hippocrates (who, in turn, most likely drank in Egyptian knowledge). Knowledge was concentrated in Alexandria after the conquest of Egypt by Alexander the Great; The city’s world-famous library housed a wealth of books related to medicine and human anatomy.

        In fact, it was Herophilus of Chalcedon who established one of the currents that would prevail later in the Middle Ages. This Greek sage described the configuration of the cerebral cortex and its ventricles, in which he asserted that the higher functions were to be found. Gregor Reich collects this theory several centuries later, in his work Margarita Philosophica.

        Galen was one of the great figures of classical medicine. His works contain many errors (it is believed that due to the ban on dissecting human corpses, the doctor had to be content with animals). However, he sensed what would be another of the currents that would remain in force in medieval times: he placed the mind, and therefore the reasoning, in the brain tissue.

        The Middle Ages, the brain and the “stone of madness”

        Heir to classical wisdom, the medieval period includes, as we have already indicated, the main theories of Herophilus and Galen. In the Middle Ages it was thought that the higher functions (reasoning, emotions…) were found in the ventricles of the brain. Thus, madness or dementia is considered to be the manifestation of a problem in these areas of the brain.

        For the medieval human being, insanity is caused by the formation of mineral strata that press on the brain or clog the ventricles. Therefore, it is quite common to find at that time supposed “doctors” who proposed to pierce “insane” (a rather ambiguous term in the Middle Ages) and thus extract the “stone of madness”. Famous is the painting by El Bosco, kept in the Museo del Prado, where the artist makes a caricature of such an activity: a charlatan extracts the stone from the head of a man, who allows himself to be deceived by the evil arts of the liar. In El Bosco’s painting, a tulip appears instead of the stone, a clear reference to the deception of which the man is a victim, as well as to his own need.

        In the Middle Ages, madness was confronted in a contradictory way. The “madman” can be a visionary, a being who sees things that others do not see (and this is why tributes are dedicated to him such as the Fiesta de los Locos, an authentic exaltation of madness) or he can be a demon possessed expel from the community.

        In all cases, the only solution is exorcism or the extraction of the stone that causes dementia.

        I forbid dissecting

        The Middle Ages were not the only time when the dissection of corpses for anatomical study was prohibited. Already in Greek and Roman times, there were prejudices in this regard; We have already commented on how Galen had to experiment with dead animals to reach his conclusions.

        Around the 13th century, dissections of human bodies began to become more frequent, although the scarcity of corpses fueled the assault on the tombs, so the authorities decided to put restrictions again. Already in the 15th century we find a more or less common activity concerning the dissection of corpses: Leonardo da Vinci himself practiced dissections to study human anatomy.

        This advance in direct exploration of the human body helped streamline the study of the brain, and early neurological studies began to proliferate.

        The scientific revolution

        In the 16th century, Andrés Vesalio published his De humani corpus fabrica, a major work that represents a turning point in the study of human anatomy and therefore of the brain. This large-scale work (no less than 10 volumes) laid the foundations of modern brain anatomy.

        Based on his lectures at the University of Padua, this compilation by Vesalius draws on dissections of corpses to present a detailed examination of various organs. Advances in printing have made it possible to accompany the books with high-quality engravings that perfectly illustrate the explanations. In this work, it is emphasized that the ventricles of the brain are the place where functions such as memory or emotions are located.

        A little later, Nicolás Steno, a doctor Danish, states that the brain is the most delicate part of the human body and therefore needs to be taken care of to avoid malfunction that culminates in madness. For his part, Thomas Willis used the term neurology for the first time, associating the Greek word neuro (rope) with logos. Willis is considered the father of modern neurology; in his book Cerebri Anatome, this English doctor makes a very precise description of the internal morphology of the brain.

        Already in the 18th century, Giambattista Morgagni links diseases to anatomical lesions for the first time; for example, he claimed that apoplexy was caused by damage to the veins of the brain. Morgagni is the author of the first book on pathological anatomy.

          The 19th century, a time of progress?

          The 19th century will mark an important advance in the study of the brain. Santiago Ramon y Cajal published his works on the nervous system, where he stated that it is composed of independent cells connected to each other at specific places (neurons). His work earned him the Nobel Prize for Medicine in 1906 and laid the foundations of current neuroscience.

          However, the so-called century of progress also had its black spots. Darwin’s theory of evolution led to the appearance of racist theories that attempted to “justify” the inferiority of races. In other words, the absurd theory spread that there were human groups more evolved than others. This idea reached its peak in the 20th century, when the Nazi party tried to “prove” the supremacy of the Aryan race by measuring skulls and other even more macabre experiments.

          The study of the brain continues its course. We are getting closer and closer to understanding this fascinating organ as a whole, but there are still many doors to open.

          Bibliographic references

          • Several authors, History of Neuroanatomy, Museo Archivo Histórico SEN, 2009
          • Various authors, The Edwin Smith papyrus and its medical and dental significance, Revista médica de Chile, 2012
          • Peñalta Catalán, Rocío, Locos and madness at the end of the Middle Ages, Revista de philología romanica, vol. 25 years old, Complutense University of Madrid, 2008

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