neuron
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...
s, there is evidence of
neuroscience
Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, development ...
practice throughout the early periods of history. The early civilizations lacked adequate means to obtain knowledge about the human brain. Their assumptions about the inner workings of the mind, therefore, were not accurate. Early views on the function of the
brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...
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
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...
that was assumed to be the seat of intelligence. According to
Herodotus
Herodotus ( ; grc, , }; BC) was an ancient Greek historian and geographer from the Greek city of Halicarnassus, part of the Persian Empire (now Bodrum, Turkey) and a later citizen of Thurii in modern Calabria ( Italy). He is known f ...
, 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".
Antiquity
The earliest reference to the brain occurs in the
Edwin Smith Surgical Papyrus
The Edwin Smith Papyrus is an ancient Egyptian medical manual, medical text, named after Edwin Smith (Egyptologist), Edwin Smith who bought it in 1862, and the oldest known surgical treatise on trauma (medicine), trauma. From a cited quotation in ...
, written in the 17th century BC. The
hieroglyph
A hieroglyph ( Greek for "sacred carvings") was a character of the ancient Egyptian writing system. Logographic scripts that are pictographic in form in a way reminiscent of ancient Egyptian are also sometimes called "hieroglyphs". In Neoplatoni ...
for brain, 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. The assessments of the author (a battlefield surgeon) of the papyrus allude to ancient Egyptians having a vague recognition of the effects of head trauma. While the symptoms are well written and detailed, the absence of a medical precedent is apparent. The author of the passage notes "the pulsations of the exposed brain" and compared the surface of the brain to the rippling surface of copper slag (which indeed has a gyral-sulcal pattern). The laterality of injury was related to the laterality of symptom, and both aphasia ("he speaks not to thee") and seizures ("he shudders exceedingly") after head injury were described. Observations by ancient civilizations of the human brain suggest only a relative understanding of the basic mechanics and the importance of cranial security. Furthermore, considering the general consensus of medical practice pertaining to human anatomy was based on myths and superstition, the thoughts of the battlefield surgeon appear to be empirical and based on logical deduction and simple observation.
In
Ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...
, interest in the brain began with the work of Alcmaeon, who appeared to have dissected the eye and related the brain to vision. He also suggested that the brain, not the heart, was the organ that ruled the body (what Stoics would call the ''hegemonikon'') and that the senses were dependent on the brain. According to ancient authorities, Alcmaeon believed the power of the brain to synthesize sensations made it also the seat of memories and thought. The author of ''
On the Sacred Disease
''On the Sacred Disease'' is a work of the Hippocratic Corpus, written about 400 B.C. Its authorship cannot be confirmed, so is regarded as dubious. The treatise is thought to contain one of the first recorded observations of epilepsy in humans. ...
'', part of the Hippocratic corpus, likewise believed the brain to be the seat of intelligence.
The debate regarding the ''hegemonikon'' persisted among ancient Greek philosophers and physicians for a very long time. Already in the 4th century BC,
Aristotle
Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...
thought that the heart was the seat of
intelligence
Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can b ...
, while 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. On the opposite end, during the
Hellenistic period
In Classical antiquity, the Hellenistic period covers the time in Mediterranean history after Classical Greece, between the death of Alexander the Great in 323 BC and the emergence of the Roman Empire, as signified by the Battle of Actium in 3 ...
,
Herophilus
Herophilos (; grc-gre, Ἡρόφιλος; 335–280 BC), sometimes Latinised Herophilus, was a Greek physician regarded as one of the earliest anatomists. Born in Chalcedon, he spent the majority of his life in Alexandria. He was the first ...
and
Erasistratus
Erasistratus (; grc-gre, Ἐρασίστρατος; c. 304 – c. 250 BC) 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 th ...
of Alexandria engaged in studies that involved
dissecting
Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause of ...
human bodies, providing evidence for the primacy of the brain. They affirmed the distinction between the
cerebrum
The cerebrum, telencephalon or endbrain is the largest part of the brain containing the cerebral cortex (of the two cerebral hemispheres), as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In ...
and the
cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...
dura mater
In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...
''. Their works are now mostly lost, and 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 Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterr ...
, the Greek physician and philosopher
Galen
Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of ...
dissected the brains of
oxen
An ox ( : oxen, ), also known as a bullock (in BrE
British English (BrE, en-GB, or BE) is, according to Oxford Dictionaries, "English as used in Great Britain, as distinct from that used elsewhere". More narrowly, it can refer spec ...
, Barbary apes, swine, and other non-human mammals. He concluded that, as the cerebellum was denser than the brain, it must control the
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
s, while as the cerebrum was soft, it must be where the senses were processed. Galen further theorized that the brain functioned by the movement of animal spirits through the ventricles. He also noted that specific spinal nerves controlled specific muscles, and had the idea of the reciprocal action of muscles. Only in the 19th century, in the work of
François Magendie
__NOTOC__
François Magendie (6 October 1783 – 7 October 1855) was a French physiologist, considered a pioneer of experimental physiology. He is known for describing the foramen of Magendie. There is also a ''Magendie sign'', a downward ...
and
Charles Bell
Sir Charles Bell (12 November 177428 April 1842) was a Scotland, Scottish surgeon, anatomist, physiologist, neurologist, artist, and philosophical theologian. He is noted for discovering the difference between sensory nerves and motor nerves in ...
, would the understanding of spinal function surpass that of Galen.
Medieval to Early Modern
Islamic medicine in the middle ages was focused on how the mind and body interacted and emphasized a need to understand mental health.
Circa 1000,
Al-Zahrawi
Abū al-Qāsim Khalaf ibn al-'Abbās al-Zahrāwī al-Ansari ( ar, أبو القاسم خلف بن العباس الزهراوي; 936–1013), popularly known as al-Zahrawi (), Latinised as Albucasis (from Arabic ''Abū al-Qāsim''), was ...
, living in
Islamic Iberia
Al-Andalus translit. ; an, al-Andalus; ast, al-Ándalus; eu, al-Andalus; ber, ⴰⵏⴷⴰⵍⵓⵙ, label=Berber, translit=Andalus; ca, al-Àndalus; gl, al-Andalus; oc, Al Andalús; pt, al-Ândalus; es, al-Ándalus () was the Mus ...
, evaluated neurological patients and performed surgical treatments of head injuries, skull fractures, spinal injuries, hydrocephalus, subdural effusions and headache. In
Persia
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
,
Avicenna
Ibn Sina ( fa, ابن سینا; 980 – June 1037 CE), commonly known in the West as Avicenna (), was a Persian polymath who is regarded as one of the most significant physicians, astronomers, philosophers, and writers of the Islamic G ...
(Ibn-Sina) presented detailed knowledge about skull fractures and their surgical treatments.
Avicenna is regarded by some as the father of modern medicine. He wrote 40 pieces on medicine with the most notable being the Qanun, a medical encyclopedia that would become a staple at universities for nearly a hundred years. He also explained phenomena such as, insomnia, mania, hallucinations, nightmares, dementia, epilepsy, stroke, paralysis, vertigo, melancholia and tremors. He also discovered a condition similar to schizophrenia, which he called Junun Mufrit, characterized by agitation, behavioral and sleep disturbances, giving inappropriate answers to questions, and occasional inability to speak. Avicenna also discovered the cerebellar vermis, which he simply called the vermis, and the caudate nucleus. Both terms are still used in neuroanatomy today. He was also the first person to associate mental deficits with deficits in the brain's middle ventricle or frontal lobe.
Abulcasis
Abū al-Qāsim Khalaf ibn al-'Abbās al-Zahrāwī al-Ansari ( ar, أبو القاسم خلف بن العباس الزهراوي; 936–1013), popularly known as al-Zahrawi (), Latinised as Albucasis (from Arabic ''Abū al-Qāsim''), was ...
,
Averroes
Ibn Rushd ( ar, ; full name in ; 14 April 112611 December 1198), often Latinized as Averroes ( ), was an
Andalusian polymath and jurist who wrote about many subjects, including philosophy, theology, medicine, astronomy, physics, psycholog ...
Maimonides
Musa ibn Maimon (1138–1204), commonly known as Maimonides (); la, Moses Maimonides and also referred to by the acronym Rambam ( he, רמב״ם), was a Sephardic Jewish philosopher who became one of the most prolific and influential Torah ...
, active in the Medieval Muslim world, also described a number of medical problems related to the brain.
Between the 13th and 14th centuries, the first
anatomy
Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...
textbooks in Europe, which included a description of the brain, were written by
Mondino de Luzzi
Mondino de Luzzi, or de Liuzzi or de Lucci,The family name is spelled variously: Liucci, Lucci, Luzzi or Luzzo (Latin: de Luciis, de Liuccis, de Leuciis); the ''dei'' may be contracted to ''de'' or ''de''. SeeGiorgi, P.P. (2004) "Mondino de' Li ...
and
Guido da Vigevano
Guido da Vigevano or Guido da Vigevano da Pavia (born c. 1280; died c. 1349) was an Italian physician and inventor. He is notable for his sketchbook ''Texaurus regis Francie'', a catalog of military equipment, and his ''Anothomia Philippi Septimi' ...
.
Renaissance
Work by
Andreas Vesalius
Andreas Vesalius (Latinized from Andries van Wezel) () was a 16th-century anatomist, physician, and author of one of the most influential books on human anatomy, ''De Humani Corporis Fabrica Libri Septem'' (''On the fabric of the human body'' ' ...
on human cadavers found problems with the Galenic view of anatomy. Vesalius noted many structural characteristics of both the brain and general nervous system during his dissections. In addition to recording many anatomical features such as the
putamen
The putamen (; from Latin, meaning "nutshell") is a round structure located at the base of the forebrain (telencephalon). The putamen and caudate nucleus together form the dorsal striatum. It is also one of the structures that compose the basal n ...
and
corpus callosum
The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental m ...
, Vesalius proposed that the brain was made up of seven pairs of 'brain nerves', each with a specialized function. Other scholars furthered Vesalius' work by adding their own detailed sketches of the human brain.
Scientific Revolution
In the 17th century,
René Descartes
René Descartes ( or ; ; Latinized: Renatus Cartesius; 31 March 1596 – 11 February 1650) was a French philosopher, scientist, and mathematician, widely considered a seminal figure in the emergence of modern philosophy and science. Mathem ...
studied the
physiology
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
of the brain, proposing the theory of dualism to tackle the issue of the brain's relation to the mind. He suggested that the
pineal gland
The pineal gland, conarium, or epiphysis cerebri, is a small endocrine gland in the brain of most vertebrates. The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep, sleep patterns in both circadian rhythm, circ ...
was where the mind interacted with the body after recording the brain mechanisms responsible for circulating
cerebrospinal fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...
.
Jan Swammerdam
Jan Swammerdam (February 12, 1637 – February 17, 1680) was a Dutch biologist and microscopist. His work on insects demonstrated that the various phases during the life of an insect—egg, larva, pupa, and adult—are different forms of the ...
placed severed frog thigh muscle in an airtight syringe with a small amount of water in the tip and when he caused the muscle to contract by irritating the nerve, the water level did not rise but rather was lowered by a minute amount debunking balloonist theory. The idea that nerve stimulation led to movement had important implications by putting forward the idea that behaviour is based on stimuli.
Thomas Willis
Thomas Willis FRS (27 January 1621 – 11 November 1675) was an English doctor who played an important part in the history of anatomy, neurology and psychiatry, and was a founding member of the Royal Society.
Life
Willis was born on his pare ...
studied the brain, nerves, and behavior to develop neurologic treatments. He described in great detail the structure of the
brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is cont ...
, the cerebellum, the ventricles, and the cerebral hemispheres.
Giovanni Aldini
Giovanni Aldini (10 April 1762 – 17 January 1834) was an Italian physician and physicist born in Bologna. He was a brother of the statesman Count Antonio Aldini (1756–1826). He graduated in Physic at University of Bologna in 1782.
He became ...
in the second half of the 18th century. In 1811,
César Julien Jean Legallois
César Julien Jean (also "Julien Jean César) Legallois" (also ''Le Gallois;'') (1 February 1770 at Cherrueix, Bretagne – 10 February 1814 in Paris) was a French physician and physiologist.
Life
César Julien Jean Legallois was the son of ...
defined a specific function of a brain region for the first time. He studied respiration in animal dissection and lesions, and found the center of respiration in the medulla oblongata. Between 1811 and 1824,
Charles Bell
Sir Charles Bell (12 November 177428 April 1842) was a Scotland, Scottish surgeon, anatomist, physiologist, neurologist, artist, and philosophical theologian. He is noted for discovering the difference between sensory nerves and motor nerves in ...
and
François Magendie
__NOTOC__
François Magendie (6 October 1783 – 7 October 1855) was a French physiologist, considered a pioneer of experimental physiology. He is known for describing the foramen of Magendie. There is also a ''Magendie sign'', a downward ...
discovered through
dissection
Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause o ...
and
vivisection
Vivisection () is surgery conducted for experimental purposes on a living organism, typically animals with a central nervous system, to view living internal structure. The word is, more broadly, used as a pejorative catch-all term for Animal testi ...
that the ventral roots in spine transmit motor impulses and the posterior roots receive sensory input ( Bell-Magendie law). In the 1820s, Jean Pierre Flourens pioneered the experimental method of carrying out localized lesions of the brain in animals describing their effects on motricity, sensibility and behavior. He concluded that the ablation of the cerebellum resulted in movements that “were not regular and coordinated". At mid century,
Emil du Bois-Reymond
Emil Heinrich du Bois-Reymond (7 November 181826 December 1896) was a German physician and physiologist, the co-discoverer of nerve action potential, and the developer of experimental electrophysiology.
Life
Du Bois-Reymond was born in Berlin a ...
,
Johannes Peter Müller
Johannes Peter Müller (14 July 1801 – 28 April 1858) was a German physiologist, comparative anatomy, comparative anatomist, ichthyology, ichthyologist, and herpetology, herpetologist, known not only for his discoveries but also for his ability ...
, and
Hermann von Helmholtz
Hermann Ludwig Ferdinand von Helmholtz (31 August 1821 – 8 September 1894) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The Helmholtz Association, ...
showed neurons were electrically excitable and that their activity predictably affected the electrical state of adjacent neurons.
In 1848,
John Martyn Harlow
John Martyn Harlow (November 25, 1819 – May 13, 1907) was an American physician primarily remembered for his attendance on brain-injury survivor Phineas Gage, and for his published reports on Gage's accident and subsequent history.
Har ...
described that Phineas Gage had his frontal lobe pierced by an iron tamping rod in a blasting accident. He became a case study in the connection between the
prefrontal cortex
In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, ...
and
executive functions
In cognitive science and neuropsychology, executive functions (collectively referred to as executive function and cognitive control) are a set of cognitive processes that are necessary for the cognitive control of behavior: selecting and succe ...
. In 1861, Paul Broca heard of a patient at the
Bicêtre Hospital
The Bicêtre Hospital is located in Le Kremlin-Bicêtre, a commune in the southern suburbs of Paris, France. It lies 4.5 km (2.8 miles) from the center of Paris. The Bicêtre Hospital was originally planned as a military hospital, with constr ...
who had a 21-year progressive loss of speech and paralysis but neither a loss of comprehension nor mental function. Broca performed an autopsy and determined that the patient had a
lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals.
Types
There is no designated classifi ...
in the
frontal lobe
The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove betwe ...
in the left
cerebral hemisphere
The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres ...
. Broca published his findings from the autopsies of twelve patients in 1865. His work inspired others to perform careful autopsies with the aim of linking more brain regions to sensory and motor functions. Another French neurologist,
Marc Dax
Marc Dax (27 December 1770 – 3 June 1837) was a French neurologist, sometimes credited for discovering the link between neurological damage to the left hemisphere, right-sided hemiplegia, and a loss of the ability to produce speech (aphasia). He ...
, made similar observations a generation earlier.Principles of Neural Science, 4th ed. Eric R. Kandel, James H. Schwartz, Thomas M. Jessel, eds. McGraw-Hill: New York, NY. 2000. Broca's hypothesis was supported by
Gustav Fritsch
Gustav Theodor Fritsch (5 March 1838 – 12 June 1927) was a German anatomist, anthropologist, traveller and physiologist from Cottbus.
Fritsch studied natural science and medicine in Berlin, Breslau and Heidelberg. In 1874 he became an ass ...
and
Eduard Hitzig
Eduard Hitzig (6 February 1838 – 20 August 1907) was a German neurologist and neuropsychiatrist of Jewish ancestryAndrew P. Wickens, ''A History of the Brain: From Stone Age Surgery to Modern Neuroscience'', Psychology Press (2014), p. 226 b ...
who discovered in 1870 that electrical stimulation of motor cortex caused involuntary muscular contractions of specific parts of a dog's body and by observations of
epileptic
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical ...
patients conducted by John Hughlings Jackson, who correctly deduced in the 1870s the organization of the
motor cortex
The motor cortex is the region of the cerebral cortex believed to be involved in the planning, control, and execution of voluntary movements.
The motor cortex is an area of the frontal lobe located in the posterior precentral gyrus immediately ...
by watching the progression of seizures through the body.
Carl Wernicke
Carl (or Karl) Wernicke (; ; 15 May 1848 – 15 June 1905) was a German physician, anatomist, psychiatrist and neuropathologist. He is known for his influential research into the pathological effects of specific forms of encephalopathy and also ...
further developed the theory of the specialization of specific brain structures in language comprehension and production.
Richard Caton
Richard Caton (1842, Bradford – 1926), of Liverpool, England, was a British physician, physiologist and Lord Mayor of Liverpool who was crucial in discovering the electrical nature of the brain and laid the groundwork for Hans Berger to disco ...
presented his findings in 1875 about electrical phenomena of the cerebral hemispheres of rabbits and monkeys. In 1878,
Hermann Munk
Hermann Munk (3 February 1839 – 1 October 1912) was a German physiologist. He was born at Posen, studied at Berlin and Göttingen, and in 1862 became docent in the former university. Seven years afterward he was promoted to assistant profess ...
found in dogs and monkeys that vision was localized in the occipital cortical area,
David Ferrier
Sir David Ferrier FRS (13 January 1843 – 19 March 1928) was a pioneering Scottish neurologist and psychologist. Ferrier conducted experiments on the brains of animals such as monkeys and in 1881 became the first scientist to be prosecuted ...
Harvey Cushing
Harvey Williams Cushing (April 8, 1869 – October 7, 1939) was an American neurosurgeon, pathologist, writer, and draftsman. A pioneer of brain surgery, he was the first exclusive neurosurgeon and the first person to describe Cushing's disease. ...
found in 1909 that the sense of touch was localized in the postcentral gyrus. Modern research still uses the
Korbinian Brodmann
Korbinian Brodmann (17 November 1868 – 22 August 1918) was a German neurologist who became famous for mapping the cerebral cortex and defining 52 distinct regions, known as Brodmann areas, based on their cytoarchitectonic (histological) char ...
'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.
Studies of the brain became more sophisticated after the invention of the
microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...
and the development of a staining procedure by
Camillo Golgi
Camillo Golgi (; 7 July 184321 January 1926) was an Italian biologist and pathologist known for his works on the central nervous system. He studied medicine at the University of Pavia (where he later spent most of his professional career) betwee ...
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 (; 1 May 1852 – 17 October 1934) was a Spanish neuroscientist, pathologist, and histologist specializing in neuroanatomy and the central nervous system. He and Camillo Golgi received the Nobel Prize in Physiology or Me ...
and led to the formation of the
neuron doctrine
The neuron doctrine is the concept that the nervous system is made up of discrete individual cells, a discovery due to decisive neuro-anatomical work of Santiago Ramón y Cajal and later presented by, among others, H. Waldeyer-Hartz. The term '' ...
, 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
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accord ...
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 Galvani's pioneering work in the electrical excitability of muscles and neurons. In 1898, British scientist
John Newport Langley
John Newport Langley (2 November 1852 – 5 November 1925) was a British physiologist, who made substantive discoveries about the nervous system and secretion.
Life
He was born in Newbury, Berkshire the son of John Langley, the local schoolmast ...
first coined the term "autonomic" in classifying the connections of nerve fibers to peripheral nerve cells. Langley is known as one of the fathers of the
chemical receptor
A chemoreceptor, also known as chemosensor, is a specialized sensory receptor which transduces a chemical substance (endogenous or induced) to generate a biological signal. This signal may be in the form of an action potential, if the chemorecept ...
theory, and as the origin of the concept of "receptive substance". Towards the end of the nineteenth century
Francis Gotch
Francis Gotch (13 July 1853 – 15 July 1913) was a British neurophysiologist who was professor of physiology at University College Liverpool and Oxford University.
He was educated at Amersham Hall School and then at London University graduati ...
conducted several experiments on nervous system function. In 1899 he described the "inexcitable" or "refractory phase" that takes place between
nerve impulse
An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, ...
s. His primary focus was on how nerve interaction affected the muscles and eyes.
Heinrich Obersteiner in 1887 founded the ‘‘Institute for Anatomy and Physiology of the CNS’’, later called Neurological or Obersteiner Institute of the Vienna University School of Medicine. It was one of the first brain research institutions in the world. He studied the cerebellar cortex, described the
Redlich–Obersteiner's zone
The Redlich–Obersteiner's zone, also known as the root entry zone, is a boundary between the central nervous system (CNS) and the peripheral nervous system (PNS).Róbert Bárány, who worked on the physiology and pathology of the vestibular apparatus, attended this school, graduating in 1900. Obersteiner was later superseded by
Otto Marburg
Otto Marburg (May 25, 1874 – June 13, 1948) was an Austrian neurologist known for his contributions to the understanding of multiple sclerosis and for advances in neurooncology.
Marburg was born in Römerstadt in Moravia, Austria-Hungary ...
.
Twentieth Century
Neuroscience during the twentieth century began to be recognized as a distinct unified academic discipline, rather than studies of the nervous system being a factor of science belonging to a variety of disciplines.
Ivan Pavlov
Ivan Petrovich Pavlov ( rus, Ива́н Петро́вич Па́влов, , p=ɪˈvan pʲɪˈtrovʲɪtɕ ˈpavləf, a=Ru-Ivan_Petrovich_Pavlov.ogg; 27 February 1936), was a Russian and Soviet experimental neurologist, psychologist and physiol ...
contributed to many areas of neurophysiology. Most of his work involved research in
temperament
In psychology, temperament broadly refers to consistent individual differences in behavior that are biologically based and are relatively independent of learning, system of values and attitudes.
Some researchers point to association of temperam ...
Institute of Experimental Medicine
The Institute of Experimental Education in St Petersburg is one of the oldest scientific establishments in Russia. It was founded by Alexander of Oldenburg in 1888 along the lines of Louis Pasteur's Pasteur Institute
The Pasteur Institute (f ...
in St. Petersburg to organize and direct the Department of Physiology. He published ''The Work of the Digestive Glands'' in 1897, after 12 years of research. His experiments earned him the 1904 Nobel Prize in Physiology and Medicine. During the same period,
Vladimir Bekhterev
Vladimir Mikhailovich Bekhterev ( rus, Влади́мир Миха́йлович Бе́хтерев, p=ˈbʲextʲɪrʲɪf; January 20, 1857 – December 24, 1927) was a Russian neurologist and the father of objective psychology. He is best know ...
discovered 15 new reflexes and is known for his competition with Pavlov regarding the study of conditioned reflexes. He founded the Psychoneurological Institute at the St. Petersburg State Medical Academy in 1907 where he worked with
Alexandre Dogiel
Alexander Stanislavovich Dogiel (russian: Александр Станиславович Догель; 1852 in Panevėžys – 1922 in Saint Petersburg), was a Russian Empire histologist and neuroscientist. The cells of Dogiel, bipolar neurons of t ...
Moscow
Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...
,
Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
was established on July 14, 1950.
Charles Scott Sherrington
Sir Charles Scott Sherrington (27 November 1857 – 4 March 1952) was an eminent English neurophysiologist. His experimental research established many aspects of contemporary neuroscience, including the concept of the spinal reflex as a system ...
's work focused strongly on reflexes and his experiments led up to the discovery of motor units. His concepts centered around unitary behaviour of cells activated or inhibited at what he called synapses. Sherrington received the Nobel prize for showing that reflexes require integrated activation and demonstrated reciprocal innervation of muscles ( Sherrington's law). Sherrington also worked with
Thomas Graham Brown
Thomas Graham Brown FRS (usually known as T. Graham Brown; 27 March 1882 – 28 October 1965) was a Scottish mountaineer and physiologist, most famous for finding three new routes up the east face of Mont Blanc.
Life and academic work
Graham B ...
who developed one of the first ideas about
central pattern generators
Central pattern generators (CPGs) are self-organizing Neural circuit, biological neural circuits that produce rhythmic outputs in the absence of rhythmic input. They are the source of the tightly-coupled patterns of neural activity that drive rhyth ...
in 1911. Brown recognized that the basic pattern of stepping can be produced by the spinal cord without the need of descending commands from the cortex.
Acetylcholine was the first
neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell.
Neuro ...
to be identified. It was first identified in 1915 by
Henry Hallett Dale
Sir Henry Hallett Dale (9 June 1875 – 23 July 1968) was an English pharmacologist and physiologist. For his study of acetylcholine as agent in the chemical transmission of nerve pulses (neurotransmission) he shared the 1936 Nobel Prize in Ph ...
for its actions on heart tissue. It was confirmed as a neurotransmitter in 1921 by
Otto Loewi
Otto Loewi (; 3 June 1873 – 25 December 1961) was a German-born pharmacologist and psychobiologist who discovered the role of acetylcholine as an endogenous neurotransmitter. For his discovery he was awarded the Nobel Prize in Physiology or M ...
in
Graz
Graz (; sl, Gradec) is the capital city of the Austrian state of Styria and second-largest city in Austria after Vienna. As of 1 January 2021, it had a population of 331,562 (294,236 of whom had principal-residence status). In 2018, the popul ...
. Loewi demonstrated the ″humorale Übertragbarkeit der Herznervenwirkung″ first in
amphibian
Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...
s. He initially gave it the name
Vagusstoff
Vagusstoff (literally translated from German as "Vagus Substance") refers to the substance released by stimulation of the vagus nerve which causes a reduction in the heart rate. Discovered in 1921 by physiologist Otto Loewi, ''vagusstoff'' was ...
because it was released from the
vagus nerve
The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right ...
and in 1936 he wrote: ″I no longer hesitate to identify the ''Sympathicusstoff'' with adrenaline.″
One major question for neuroscientists in the early twentieth century was the physiology of nerve impulses. In 1902 and again in 1912,
Julius Bernstein
Julius Bernstein (18 December 1839 – 6 February 1917) was a German physiologist born in Berlin. His father was Aron Bernstein (1812—1884), a founder of the Reform Judaism Congregation in Berlin 1845; his son was the mathematician Felix ...
advanced the hypothesis that the action potential resulted from a change in the permeability of the axonal membrane to ions. Bernstein was also the first to introduce the
Nernst equation
In electrochemistry, the Nernst equation is a chemical thermodynamical relationship that permits the calculation of the reduction potential of a reaction ( half-cell or full cell reaction) from the standard electrode potential, absolute tempe ...
for
resting potential A relatively static membrane potential which is usually referred to as the ground value for trans-membrane voltage.
The relatively static membrane potential of quiescent cells is called the resting membrane potential (or resting voltage), as opp ...
across the membrane. In 1907, Louis Lapicque suggested that the action potential was generated as a threshold was crossed, what would be later shown as a product of the
dynamical system
In mathematics, a dynamical system is a system in which a Function (mathematics), function describes the time dependence of a Point (geometry), point in an ambient space. Examples include the mathematical models that describe the swinging of a ...
s of ionic conductances. A great deal of study on sensory organs and the function of nerve cells was conducted by British physiologist Keith Lucas and his protege
Edgar Adrian
Edgar Douglas Adrian, 1st Baron Adrian (30 November 1889 – 4 August 1977) was an English electrophysiologist and recipient of the 1932 Nobel Prize for Physiology, won jointly with Sir Charles Sherrington for work on the function of neurons. ...
. Keith Lucas' experiments in the first decade of the twentieth century proved that muscles contract entirely or not at all, this was referred to as the all-or-none principle. Edgar Adrian observed nerve fibers in action during his experiments on frogs. This proved that scientists could study nervous system function directly, not just indirectly. This led to a rapid increase in the variety of experiments conducted in the field of
neurophysiology
Neurophysiology is a branch of physiology and neuroscience that studies nervous system function rather than nervous system architecture. This area aids in the diagnosis and monitoring of neurological diseases. Historically, it has been dominated b ...
and innovation in the technology necessary for these experiments. Much of Adrian's early research was inspired by studying the way vacuum tubes intercepted and enhanced coded messages. Concurrently, Josepht Erlanger and Herbert Gasser were able to modify an
oscilloscope
An oscilloscope (informally a scope) is a type of electronic test instrument that graphically displays varying electrical voltages as a two-dimensional plot of one or more signals as a function of time. The main purposes are to display repetiti ...
to run at low voltages and were able to observe that action potentials occurred in two phases—a spike followed by an after-spike. They discovered that nerves were found in many forms, each with their own potential for excitability. With this research, the pair discovered that the velocity of action potentials was directly proportional to the diameter of the nerve fiber and received a Nobel Prize for their work.
Kenneth Cole joined
Columbia University
Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...
in 1937 and remained there until 1946 where he made pioneering advances modelling the electrical properties of nervous tissue. Bernstein's hypothesis about the action potential was confirmed by Cole and Howard Curtis, who showed that membrane conductance increases during an action potential. David E. Goldman worked with Cole and derived the
Goldman equation
The Goldman–Hodgkin–Katz voltage equation, more commonly known as the Goldman equation, is used in cell membrane physiology to determine the reversal potential across a cell's membrane, taking into account all of the ions that are permeant t ...
in 1943 at Columbia University.
Alan Lloyd Hodgkin
Sir Alan Lloyd Hodgkin (5 February 1914 – 20 December 1998) was an English physiologist and biophysicist who shared the 1963 Nobel Prize in Physiology or Medicine with Andrew Huxley and John Eccles.
Early life and education
Hodgkin was ...
spent a year (1937–38) at the Rockefeller Institute, during which he joined Cole to measure the D.C. resistance of the membrane of the
squid giant axon
The squid giant axon is the very large (up to 1.5 mm in diameter; typically around 0.5 mm) axon that controls part of the water jet propulsion system in squid. It was first described by L. W. Williams in 1909, but this discovery was fo ...
in the resting state. In 1939 they began using internal electrodes inside the giant nerve fibre of the squid and Cole developed the
voltage clamp
The voltage clamp is an experimental method used by electrophysiologists to measure the ion currents through the membranes of excitable cells, such as neurons, while holding the membrane voltage at a set level. A basic voltage clamp will itera ...
technique in 1947. Hodgkin and
Andrew Huxley
Sir Andrew Fielding Huxley (22 November 191730 May 2012) was an English physiologist and biophysicist. He was born into the prominent Huxley family. After leaving Westminster School in central London, he went to Trinity College, Cambridge ...
later presented a mathematical model for transmission of electrical signals in neurons of the giant axon of a squid and how they are initiated and propagated, known as the
Hodgkin–Huxley model
The Hodgkin–Huxley model, or conductance-based model, is a mathematical model that describes how action potentials in neurons are initiated and propagated. It is a set of nonlinear differential equations that approximates the electrical charact ...
. In 1961–1962, Richard FitzHugh and J. Nagumo simplified Hodgkin–Huxley, in what is called the
FitzHugh–Nagumo model
The FitzHugh–Nagumo model (FHN), named after Richard FitzHugh (1922–2007) who suggested the system in 1961 and J. Nagumo ''et al''. who created the equivalent circuit the following year, describes a prototype of an excitable system (e.g., a n ...
neurotransmission
Neurotransmission (Latin: ''transmissio'' "passage, crossing" from ''transmittere'' "send, let through") is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron (the presynaptic neuron), ...
across the space between neurons known as synapses. Beginning in 1966, Eric Kandel and collaborators examined biochemical changes in neurons associated with learning and memory storage in ''
Aplysia
''Aplysia'' () is a genus of medium-sized to extremely large sea slugs, specifically sea hares, which are one clade of large sea slugs, marine gastropod mollusks.
These benthic herbivorous creatures can become rather large compared with most ...
''. In 1981 Catherine Morris and Harold Lecar combined these models in the Morris–Lecar model. Such increasingly quantitative work gave rise to numerous
biological neuron model
Biological neuron models, also known as a spiking neuron models, are mathematical descriptions of the properties of certain cells in the nervous system that generate sharp electrical potentials across their cell membrane, roughly one millisecon ...
s and
models of neural computation
Models of neural computation are attempts to elucidate, in an abstract and mathematical fashion, the core principles that underlie information processing in biological nervous systems, or functional components thereof. This article aims to provide ...
.
Eric Kandel
Eric Richard Kandel (; born Erich Richard Kandel, November 7, 1929) is an Austrian-born American medical doctor who specialized in psychiatry, a neuroscientist and a professor of biochemistry and biophysics at the College of Physicians and Surge ...
and collaborators have cited
David Rioch David McKenzie Rioch (July 6, 1900 – September 11, 1985) was a psychiatric research scientist and neuroanatomist, known as a pioneer in brain research and for leading the interdisciplinary neuropsychiatry division at the Walter Reed Army Institute ...
,
Francis O. Schmitt
Francis Otto Schmitt (November 23, 1903 – October 3, 1995) was an American biologist and Institute Professor at the Massachusetts Institute of Technology.
Schmitt was born November 23, 1903 to Otto and Clara Schmitt, in South St. Louis, Missou ...
, and
Stephen Kuffler
Stephen William Kuffler (August 24 Táp, Austria-Hungary, 1913 – October 11, 1980) was a pre-eminent Hungarian-American neurophysiologist. He is often referred to as the "Father of Modern Neuroscience". Kuffler, alongside noted Nobel La ...
as having played critical roles in establishing the field. Rioch originated the integration of basic anatomical and physiological research with clinical psychiatry at the
Walter Reed Army Institute of Research
The Walter Reed Army Institute of Research (WRAIR) is the largest biomedical research facility administered by the U.S. Department of Defense (DoD). The institute is centered at the Forest Glen Annex, in the Forest Glen Park part of the uni ...
, starting in the 1950s. During the same period, Schmitt established a neuroscience research program within the Biology Department at the
Massachusetts Institute of Technology
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...
, bringing together biology, chemistry, physics, and mathematics. The first freestanding neuroscience department (then called Psychobiology) was founded in 1964 at the
University of California, Irvine
The University of California, Irvine (UCI or UC Irvine) is a public land-grant research university in Irvine, California. One of the ten campuses of the University of California system, UCI offers 87 undergraduate degrees and 129 graduate and pr ...
Stephen Kuffler
Stephen William Kuffler (August 24 Táp, Austria-Hungary, 1913 – October 11, 1980) was a pre-eminent Hungarian-American neurophysiologist. He is often referred to as the "Father of Modern Neuroscience". Kuffler, alongside noted Nobel La ...
started the Department of Neurobiology at
Harvard Medical School
Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consi ...
in 1966. The first official use of the word "Neuroscience" may be in 1962 with
Francis O. Schmitt
Francis Otto Schmitt (November 23, 1903 – October 3, 1995) was an American biologist and Institute Professor at the Massachusetts Institute of Technology.
Schmitt was born November 23, 1903 to Otto and Clara Schmitt, in South St. Louis, Missou ...
's "
Neuroscience Research Program The Neuroscience Research Program (NRP) is an inter-university and international organisation founded during 1962 by Francis O. Schmitt, Francis Otto Schmitt and others, which marked a key moment in the foundation of neuroscience as a discipline.
A ...
", which was hosted by the
Massachusetts Institute of Technology
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...
.
Over time, brain research has gone through philosophical, experimental, and theoretical phases, with work on brain simulation predicted to be important in the future.
Neuroscience Institutes and Organizations
As a result of the increasing interest about the nervous system, several prominent neuroscience institutes and organizations have been formed to provide a forum to all neuroscientists. The largest professional neuroscience organization is the
Society for Neuroscience
The Society for Neuroscience (SfN) is a professional society, headquartered in Washington, DC, for basic scientists and physicians around the world whose research is focused on the study of the brain and nervous system. It is especially well kn ...
(SFN), which is based in the United States but includes many members from other countries.
In 2013, the
BRAIN Initiative
The White House BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies) is a collaborative, public-private research initiative announced by the Obama administration on April 2, 2013, with the goal of supporting the devel ...
was announced in the US. A International Brain Initiative was created in 2017, currently integrated by more than seven national-level brain research initiatives (US,
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
History of catecholamine research
The catecholamines comprise the endogenous substances dopamine, noradrenaline (norepinephrine), and adrenaline (epinephrine), as well as numerous artificially synthesized compounds such as isoprenaline, an anti-bradycardiac medication. Their inv ...
*
History of neuraxial anesthesia
The history of neuraxial anesthesia goes back to 1885.
19th century
In 1855, Friedrich Gaedcke (18281890) became the first to chemically isolate cocaine, the most potent alkaloid of the coca plant. Gaedcke named the compound "erythroxyline". ...
*
History of neurology and neurosurgery
The study of neurology and neurosurgery dates back to prehistoric times, but the academic disciplines did not begin until the 16th century. From an observational science they developed a systematic way of approaching the nervous system and possible ...
*
History of psychiatry
History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well ...
*
History of psychology
Psychology is defined as "the scientific study of behavior and mental processes". Philosophical interest in the human mind and behavior dates back to the ancient civilizations of Egypt, Persia, Greece, China, and India.
Psychology as a field of ...
History of science
The history of science covers the development of science from ancient times to the present. It encompasses all three major branches of science: natural, social, and formal.
Science's earliest roots can be traced to Ancient Egypt and Meso ...
*
List of neurologists
This is a list of neurologists and neurosurgeons, with their year of birth and death and nationality. This list compiles the names of neurologists and neurosurgeons with a corresponding Wikipedia biographical article, and is not necessarily a refle ...
*
List of neuroscientists
Many famous neuroscientists are from the 20th and 21st century, as neuroscience is a fairly new science. However many anatomists, physiologists, biologists, neurologists, psychiatrists and other physicians and psychologists are considered to be n ...
References
Further reading
* Rousseau, George S. (2004). ''Nervous Acts: Essays on Literature, Culture and Sensibility.'' Basingstoke: Palgrave Macmillan. (Paperback)
* Wickens, Andrew P. (2015) ''A History of the Brain: From Stone Age Surgery to Modern Neuroscience.'' London: Psychology Press. (Paperback), 978-84872-364-1 (Hardback), 978-1-315-79454-9 (Ebook)