History of the brain
Encyclopedia
Early views on the function of the brain
, regarded it to be a form of “cranial stuffing” of sorts. In ancient Egypt
, from the late Middle Kingdom
onwards, in preparation for mummification, the brain was regularly removed, for it was the heart
that was assumed to be the seat of intelligence. According to Herodotus
, during the first step of mummification: ‘The most perfect practice is to extract as much of the brain as possible with an iron hook, and what the hook cannot reach is mixed with drugs.’ Over the next five thousand years, this view came to be reversed; the brain is now known to be the seat of intelligence, although colloquial variations of the former remain as in “memorizing something by heart”.
The Edwin Smith Surgical Papyrus, written in the 17th century BC, contains the earliest recorded reference to the brain. The word brain (adjacent), occurring eight times in this papyrus, describes the symptoms, diagnosis, and prognosis of two patients, wounded in the head, who had compound fractures of the skull.
During the second half of the first millennium BC, the Ancient Greeks
developed differing views on the function of the brain. It is said that it was the Pythagorean
Alcmaeon of Croton
(6th and 5th centuries BC) who first considered the brain to be the place where the mind was located. In the 4th century BC Hippocrates
, believed the brain to be the seat of intelligence (based, among others before him, on Alcmaeon's work). During the 4th century BC Aristotle
thought that, while the heart was the seat of intelligence, the brain was a cooling mechanism for the blood. He reasoned that humans are more rational than the beasts because, among other reasons, they have a larger brain to cool their hot-bloodedness.
During the Hellenistic period, Herophilus of Calcedonia (c.335/330-280/250 BC) and Erasistratus
of Ceos (c. 300-240 BC) made fundamental contributions not only to brain and nervous systems' anatomy and physiology, but to many other fields of the bio-sciences. Their works are now mostly lost, we know about their achievements due mostly to secondary sources. Some of their discoveries had to be re-discovered a millennium after their death.
During the Roman Empire
, the Greek anatomist Galen
dissected the brains of sheep, monkeys, dogs, swine, among other non-human mammals. He concluded that, as the cerebellum
was denser than the brain, it must control the muscle
s, while as the cerebrum
was soft, it must be where the senses were processed. Galen further theorized that the brain functioned by movement of animal spirits through the ventricles
.
(1514–1564) and René Descartes
(1596–1650) also made several fundamental contributions to theory and empirical knowledge in neuroscience.
and the development of a staining procedure by Camillo Golgi
during the late 1890s that used a silver chromate salt to reveal the intricate structures of single neurons. His technique was used by Santiago Ramón y Cajal
and led to the formation of the neuron doctrine
, the hypothesis that the functional unit of the brain is the neuron. Golgi and Ramón y Cajal shared the Nobel Prize in Physiology or Medicine
in 1906 for their extensive observations, descriptions and categorizations of neurons throughout the brain. The hypotheses of the neuron doctrine were supported by experiments following Luigi Galvani
's pioneering work in the electrical excitability of muscles and neurons. In the late 19th century, Emil du Bois-Reymond
, Johannes Peter Müller
, and Hermann von Helmholtz
showed neurons were electrically excitable and that their activity predictably affected the electrical state of adjacent neurons.
In parallel with this research, work with brain-damaged patients by Paul Broca
suggested that certain regions of the brain were responsible for certain functions. This hypothesis was supported by observations of epileptic
patients conducted by John Hughlings Jackson
, who correctly deduced the organization of motor cortex
by watching the progression of seizures through the body. Carl Wernicke further developed the theory of the specialization of specific brain structures in language comprehension and production. Modern research still uses the Korbinian Brodmann
's cytoarchitectonic (referring to study of cell structure) anatomical definitions from this era in continuing to show that distinct areas of the cortex are activated in the execution of specific tasks.
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
, regarded it to be a form of “cranial stuffing” of sorts. In ancient Egypt
Ancient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
, from the late Middle Kingdom
Middle Kingdom of Egypt
The Middle Kingdom of Egypt is the period in the history of ancient Egypt stretching from the establishment of the Eleventh Dynasty to the end of the Fourteenth Dynasty, between 2055 BC and 1650 BC, although some writers include the Thirteenth and Fourteenth dynasties in the Second Intermediate...
onwards, in preparation for mummification, the brain was regularly removed, for it was the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
that was assumed to be the seat of intelligence. According to Herodotus
Herodotus
Herodotus was an ancient Greek historian who was born in Halicarnassus, Caria and lived in the 5th century BC . He has been called the "Father of History", and was the first historian known to collect his materials systematically, test their accuracy to a certain extent and arrange them in a...
, during the first step of mummification: ‘The most perfect practice is to extract as much of the brain as possible with an iron hook, and what the hook cannot reach is mixed with drugs.’ Over the next five thousand years, this view came to be reversed; the brain is now known to be the seat of intelligence, although colloquial variations of the former remain as in “memorizing something by heart”.
Early views
During the second half of the first millennium BC, the Ancient Greeks
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
developed differing views on the function of the brain. It is said that it was the Pythagorean
Pythagoreanism
Pythagoreanism was the system of esoteric and metaphysical beliefs held by Pythagoras and his followers, the Pythagoreans, who were considerably influenced by mathematics. Pythagoreanism originated in the 5th century BCE and greatly influenced Platonism...
Alcmaeon of Croton
Alcmaeon of Croton
Alcmaeon of Croton was one of the most eminent natural philosophers and medical theorists of antiquity. His father's name was Peirithus . He is said by some to have been a pupil of Pythagoras, and he may have been born around 510 BC...
(6th and 5th centuries BC) who first considered the brain to be the place where the mind was located. In the 4th century BC Hippocrates
Hippocrates
Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...
, believed the brain to be the seat of intelligence (based, among others before him, on Alcmaeon's work). During the 4th century BC Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
thought that, while the heart was the seat of intelligence, the brain was a cooling mechanism for the blood. He reasoned that humans are more rational than the beasts because, among other reasons, they have a larger brain to cool their hot-bloodedness.
During the Hellenistic period, Herophilus of Calcedonia (c.335/330-280/250 BC) and Erasistratus
Erasistratus
Erasistratus was a Greek anatomist and royal physician under Seleucus I Nicator of Syria. Along with fellow physician Herophilus, he founded a school of anatomy in Alexandria, where they carried out anatomical research...
of Ceos (c. 300-240 BC) made fundamental contributions not only to brain and nervous systems' anatomy and physiology, but to many other fields of the bio-sciences. Their works are now mostly lost, we know about their achievements due mostly to secondary sources. Some of their discoveries had to be re-discovered a millennium after their death.
During the Roman Empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....
, the Greek anatomist Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
dissected the brains of sheep, monkeys, dogs, swine, among other non-human mammals. He concluded that, as the cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
was denser than the brain, it must control the muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s, while as the cerebrum
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
was soft, it must be where the senses were processed. Galen further theorized that the brain functioned by movement of animal spirits through the ventricles
Ventricular system
The ventricular system is a set of structures containing cerebrospinal fluid in the brain. It is continuous with the central canal of the spinal cord.-Components:The system comprises four ventricles:* right and left lateral ventricles* third ventricle...
.
Renaissance
VesaliusVesalius
Andreas Vesalius was a Flemish anatomist, physician, and author of one of the most influential books on human anatomy, De humani corporis fabrica . Vesalius is often referred to as the founder of modern human anatomy. Vesalius is the Latinized form of Andries van Wesel...
(1514–1564) and René Descartes
René Descartes
René Descartes ; was a French philosopher and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the 'Father of Modern Philosophy', and much subsequent Western philosophy is a response to his writings, which are studied closely to this day...
(1596–1650) also made several fundamental contributions to theory and empirical knowledge in neuroscience.
Modern period
Studies of the brain became more sophisticated after the invention of the microscopeMicroscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
and the development of a staining procedure by Camillo Golgi
Camillo Golgi
Camillo Golgi was an Italian physician, pathologist, scientist, and Nobel laureate.-Biography:Camillo Golgi was born in the village of Corteno, Lombardy, then part of the Austrian Empire. The village is now named Corteno Golgi in his honour. His father was a physician and district medical officer...
during the late 1890s that used a silver chromate salt to reveal the intricate structures of single neurons. His technique was used by Santiago Ramón y Cajal
Santiago Ramón y Cajal
Santiago Ramón y Cajal ForMemRS was a Spanish pathologist, histologist, neuroscientist, and Nobel laureate. His pioneering investigations of the microscopic structure of the brain were original: he is considered by many to be the father of modern neuroscience...
and led to the formation of the neuron doctrine
Neuron doctrine
The neuron doctrine is a descriptive term for the fundamental concept that the nervous system is made up of discrete individual cells, a discovery due to decisive neuro-anatomical work of Santiago Ramon y Cajal and later presented, among others, by H. Waldeyer-Hartz...
, the hypothesis that the functional unit of the brain is the neuron. Golgi and Ramón y Cajal shared the Nobel Prize in Physiology or Medicine
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine administered by the Nobel Foundation, is awarded once a year for outstanding discoveries in the field of life science and medicine. It is one of five Nobel Prizes established in 1895 by Swedish chemist Alfred Nobel, the inventor of dynamite, in his will...
in 1906 for their extensive observations, descriptions and categorizations of neurons throughout the brain. The hypotheses of the neuron doctrine were supported by experiments following Luigi Galvani
Luigi Galvani
Luigi Aloisio Galvani was an Italian physician and physicist who lived and died in Bologna. In 1791, he discovered that the muscles of dead frogs legs twitched when struck by a spark...
's pioneering work in the electrical excitability of muscles and neurons. In the late 19th century, Emil du Bois-Reymond
Emil du Bois-Reymond
Emil du Bois-Reymond was a German physician and physiologist, the discoverer of nerve action potential, and the father of experimental electrophysiology.-Life:...
, Johannes Peter Müller
Johannes Peter Müller
Johannes Peter Müller , was a German physiologist, comparative anatomist, and ichthyologist not only known for his discoveries but also for his ability to synthesize knowledge.-Early years and education:...
, and Hermann von Helmholtz
Hermann von Helmholtz
Hermann Ludwig Ferdinand von Helmholtz was a German physician and physicist who made significant contributions to several widely varied areas of modern science...
showed neurons were electrically excitable and that their activity predictably affected the electrical state of adjacent neurons.
In parallel with this research, work with brain-damaged patients by Paul Broca
Paul Broca
Pierre Paul Broca was a French physician, surgeon, anatomist, and anthropologist. He was born in Sainte-Foy-la-Grande, Gironde. He is best known for his research on Broca's area, a region of the frontal lobe that has been named after him. Broca’s Area is responsible for articulated language...
suggested that certain regions of the brain were responsible for certain functions. This hypothesis was supported by observations of epileptic
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
patients conducted by John Hughlings Jackson
John Hughlings Jackson
John Hughlings Jackson, FRS , was an English neurologist.- Biography :He was born at Providence Green, Green Hammerton, near Harrogate, Yorkshire, the youngest son of Samuel Jackson, a yeoman who owned and farmed his land, and the former Sarah Hughlings, the daughter of a Welsh revenue collector...
, who correctly deduced the organization of motor cortex
Motor cortex
Motor cortex is a term that describes regions of the cerebral cortex involved in the planning, control, and execution of voluntary motor functions.-Anatomy of the motor cortex :The motor cortex can be divided into four main parts:...
by watching the progression of seizures through the body. Carl Wernicke further developed the theory of the specialization of specific brain structures in language comprehension and production. Modern research still uses the Korbinian Brodmann
Korbinian Brodmann
Korbinian Brodmann was a German neurologist who became famous for his definition of the cerebral cortex into 52 distinct regions from their cytoarchitectonic characteristics.-Life:...
's cytoarchitectonic (referring to study of cell structure) anatomical definitions from this era in continuing to show that distinct areas of the cortex are activated in the execution of specific tasks.
Further reading
- Rousseau, George S. (2004). Nervous Acts: Essays on Literature, Culture and Sensibility. Basingstoke: Palgrave Macmillan. ISBN 1-4039-3454-1 (Paperback) ISBN 1403934533