The history
From an Egyptian scroll and a squealing pig to squid axons, dream experiments and a bridge across a broken spinal cord.
For two thousand years people knew the brain and nerves controlled the body, but thought nerves were hollow pipes full of spirits. Then a twitching frog showed they carry electricity, a stopwatch showed it takes time, and microscopes showed the wiring is made of separate cells that talk with chemicals across tiny gaps. The last century turned those ideas into treatments, from L-dopa to brain scans to devices that bridge injuries.
c. 1600 BCE
Written description of the brain
Edwin Smith Papyrus, Egypt
1791
Evidence of electricity in nerves
Luigi Galvani, Italy
1850
Speed of a nerve signal measured
Hermann von Helmholtz, Prussia
1921
Chemical transmission shown
Otto Loewi, Austria
1924
Human EEG recorded
Hans Berger, Germany
1949
Neurology and neurosurgery department in India
Jacob Chandy, CMC Vellore
1952
Mathematical model of the nerve spike
Hodgkin and Huxley, England
1600 BCE – 1700
Egyptian surgeons, Alexandrian anatomists, Ayurveda and Galen tie the brain and cord to movement, but think nerves carry spirits.
1600 BCE
c. 1600 BCE (copying a text perhaps 1,000 years older)
An Egyptian surgical scroll, now called the Edwin Smith Papyrus, describes 48 injuries. It mentions the folds of the brain, the fluid around it, and notes that a broken neck can leave a person unable to move or feel their arms and legs.
Why it mattered. It is the oldest known record linking the brain and spine to movement and feeling.
300 BCE
c. 300 BCE (attributed)
Ayurvedic texts describe a condition with tremor, stiffness and slow movement, later called kampavata, and treat it with seeds of kapikacchu (Mucuna pruriens). In 1937 Indian chemists found L-dopa in those seeds, the same drug doctors now use for Parkinson’s disease.
Why it mattered. An old remedy turned out to contain the medicine that replaces missing dopamine.
280 BCE
c. 300–250 BCE
Working in Alexandria, two Greek doctors dissected human bodies. Herophilus told nerves apart from tendons and traced them to the brain and spinal cord, and he and Erasistratus separated nerves for feeling from nerves for movement.
Why it mattered. For the first time nerves were seen as the body’s own wiring, rooted in the brain.
170
c. 160s–170s CE
Galen cut the small nerves that run beside a squealing pig’s windpipe, and the pig fell silent though it still struggled. He also showed that cutting the spinal cord at different levels paralysed the body below the cut. He thought nerves were hollow tubes carrying “animal spirits”.
Why it mattered. He proved that the brain controls the body through nerves, a view that lasted 1,500 years.
1664
Willis’s “The Anatomy of the Brain” mapped the brain and its nerves in careful detail, and he is credited with coining the word neurology. He also traced the nerves that serve the heart and gut.
Why it mattered. It moved the study of the mind into the brain itself.
1780 – 1860
Galvani’s frogs, the in-and-out roots of the cord, the signal caught on a meter and timed by Helmholtz.
1791
Galvani found that frog legs twitched when their nerve was touched with metal or sparked with electricity. He published his idea of “animal electricity” in 1791. His rival Alessandro Volta disagreed, and their argument led to the battery.
Why it mattered. Nerves, it turned out, work with electricity, not spirits.
1817
A London doctor described six people with a resting tremor, a stooped posture and a shuffling walk. The condition now carries his name.
Why it mattered. Naming a disease is the first step to studying it.
1822
1811 and 1822
Bell suggested in 1811, and Magendie proved in 1822, that the roots at the back of the spinal cord carry sensations in and the roots at the front carry commands out to the muscles.
Why it mattered. It is the wiring plan of every reflex.
1849
1843–1849
With very sensitive meters, du Bois-Reymond detected a brief change in a nerve’s electrical charge whenever it carried a signal. We now call it the action potential.
Why it mattered. It showed the nerve signal itself is electrical.
1850
1849–1850 (reported January 1850)
His teacher had said nerve signals were too fast ever to measure. Helmholtz stimulated a frog’s nerve at two different distances from the muscle and timed the twitches. The difference gave a speed of about 27 metres a second (his runs gave roughly 25 to 43).
Why it mattered. Thought and feeling became physical processes that take time.
1870 – 1910
Golgi’s stain, Cajal’s neurons, Sherrington’s synapse and reflexes, and the automatic system named.
1873
Working in a hospital kitchen turned laboratory, Golgi found that silver staining turns a few whole nerve cells jet black, branches and all, against a clear background.
Why it mattered. For the first time single neurons could be seen complete.
1878
described in the 1870s (published 1878)
Ranvier described regular bare gaps in the fatty sheath around nerve fibres. They are now called nodes of Ranvier.
Why it mattered. Much later they were shown to be where the signal jumps.
1888
Using and improving Golgi’s stain, Cajal showed that nerve cells are separate units that touch but do not join, and that signals flow one way through them. In 1906 the two men shared a Nobel Prize, though Golgi still thought the nerves formed one continuous net.
Why it mattered. The neuron doctrine is the foundation of all brain science.
1897
Writing for a physiology textbook, Sherrington needed a word for the place where one neuron hands its message to the next. He chose synapse, from Greek for “to clasp”, suggested by a classics scholar.
Why it mattered. The gap he named turned out to be where most of the nervous system’s work is done.
1898
Langley coined the term autonomic nervous system for the nerves that run the organs by themselves, and later named its parasympathetic branch.
Why it mattered. It split the wiring into the part you control and the part you don’t.
1906
In “The Integrative Action of the Nervous System” Sherrington showed how reflexes combine, including how one muscle is told to relax while its partner contracts. He shared a Nobel Prize in 1932 with Edgar Adrian, who recorded single nerve fibres firing.
Why it mattered. It explained how simple circuits build smooth movement.
1906
3 November 1906
Alzheimer described Auguste Deter, a woman in her fifties with severe memory loss, and the plaques and tangles he found in her brain after she died.
Why it mattered. Today Alzheimer’s disease is the most common cause of dementia.
1910 – 1950
Fight or flight, Loewi’s dream, brain waves and the speed classes of nerve fibres.
1915
Cannon described how fear and rage make the sympathetic nerves and adrenaline speed the heart, raise blood sugar and pause digestion, preparing the body to fight or run. He later coined the word homeostasis.
Why it mattered. It gave the automatic system a purpose everyone could understand.
1921
Easter 1921
Loewi woke with an idea, lost it, dreamed it again and went straight to his lab. He stimulated the vagus nerve of one frog heart, which slowed, then dripped the fluid around it onto a second heart. That heart slowed too: the nerve had released a chemical. It proved to be acetylcholine.
Why it mattered. It proved nerves talk with chemicals, earning Loewi and Henry Dale the 1936 Nobel Prize.
1924
1924 (published 1929)
Berger recorded the first human electroencephalogram (EEG) through the scalp, finding a rhythm of about 10 waves a second when people rested with their eyes shut. He waited five years to publish.
Why it mattered. EEG is still how doctors diagnose epilepsy.
1937
1920s–1930s
Using the new cathode-ray oscilloscope, Erlanger and Gasser showed that a nerve holds fibres of different widths, and that thicker fibres carry signals faster. They won the 1944 Nobel Prize.
Why it mattered. Their A, B and C fibre classes are still used today.
1945 – today
The squid-axon model, ion channels, L-dopa, MRI, deep brain stimulation, and India’s neuro centres.
1949
Trained in Montreal under Wilder Penfield, Chandy returned to start the first department of neurology and neurosurgery in India, at the Christian Medical College. In 1958 he began India’s first training programme for neurosurgeons, whose students went on to found departments across the country.
Why it mattered. It began modern brain and spine surgery in India.
1952
Squid have a giant axon up to about 1 mm wide, big enough to put a wire inside. Hodgkin and Huxley measured how sodium rushes in and potassium flows out, and wrote equations that predict the shape and speed of the spike.
Why it mattered. Their model is still the basis of how we understand every nerve signal.
1952
1951–1953
Eccles put fine electrodes inside spinal motor neurons and recorded how some synapses push the voltage up and others pull it down. He shared the 1963 Nobel Prize with Hodgkin and Huxley.
Why it mattered. It showed a neuron decides by adding up go and stop signals.
1960
1957–1967
Carlsson showed dopamine is a transmitter in its own right. Hornykiewicz found it missing in the brains of people who had Parkinson’s disease, and Cotzias made high-dose L-dopa an effective treatment by 1967.
Why it mattered. It was the first time a brain disease was treated by replacing a missing transmitter.
1974
27 December 1974
The Mental Hospital in Bangalore, with roots in an asylum of 1847, and the All India Institute of Mental Health, opened in 1954, were joined into the National Institute of Mental Health and Neuro Sciences.
Why it mattered. It became India’s leading centre for brain, nerve and mental health care, teaching and research.
1976
By sealing a tiny glass pipette onto a cell, they recorded the current through one ion channel as it snapped open and shut. They won the 1991 Nobel Prize.
Why it mattered. It proved the gates Hodgkin and Huxley imagined are real molecules.
1987
Benabid found that steady high-frequency pulses from an electrode deep in the brain could calm a tremor without destroying tissue. It is now used for Parkinson’s disease and some other conditions.
Why it mattered. A pacemaker for the brain, switchable and adjustable.
1990
1973–1990
MRI grew from 1970s experiments into scanners that show the brain and spinal cord in sharp detail without X-rays. In 1990 Seiji Ogawa showed MRI can also track where blood oxygen changes, so functional MRI can see which areas are busy.
Why it mattered. Doctors can now see strokes, tumours and cord injuries inside a living person.
2023
A man paralysed in a cycling accident received implants over his brain and spinal cord that read his intention to move and stimulate the cord below the injury. He could stand and walk with a frame, and some control returned even with the device off.
Why it mattered. It hints that a cut in the cable may one day be bridged.
By the numbers
MoRTH annual reports. Head and spinal injuries are among the main causes of death and disability in crashes; helmets and seat belts protect the brain and cord.
Did you know?
Your brain has about 86 billion neurons, but your spinal cord is only about 45 cm long and ends at your waist.
The fastest nerve fibres carry signals at about 120 metres a second, faster than a racing car; the slowest crawl at walking pace.
Squid giant axons, up to about 1 mm wide, are so big that scientists could slide a wire inside one. That is how the nerve spike was first explained.
Otto Loewi’s famous experiment came to him in a dream, twice: the first night he could not read the note he had scribbled.
Galvani’s twitching frogs helped inspire Mary Shelley’s Frankenstein, and his argument with Volta led to the first battery.
The people
c. 129 – c. 216 · Physician · Pergamon (now Turkey), worked in Rome
Showed by experiment that nerves from the brain and cord control voice and movement.
1737 – 1798 · Physician and physicist · Bologna, Italy
Made frog legs twitch with electricity and proposed animal electricity.
1821 – 1894 · Physicist and physiologist · Potsdam, Prussia
First to time a nerve signal.
1852 – 1934 · Neuroscientist and artist · Petilla de Aragón, Spain
Showed the nervous system is built from separate neurons, and drew them beautifully.
1857 – 1952 · Physiologist · London, England
Named the synapse and explained how reflexes work together.
1873 – 1961 · Pharmacologist · Frankfurt, Germany
Proved with two frog hearts that nerves release chemicals.
1910 – 2007 · Neurosurgeon · Kerala, India
Founded India’s first neurology and neurosurgery department and training programme.
1914 – 1998 and 1917 – 2012 · Physiologists · England
Explained the nerve spike with a squid axon and a set of equations.
Where it happened
Sources
Dates marked “c.” are approximate, and historians sometimes disagree about who was first. If you spot a mistake, tell us.
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